Johnson & Starley HI-SPEC J50 User guide

132
16
15
1
6
2
5
9
10
13
8
7
14
12
4
3
11
Fig.1
FEATURES
1 Air circulation fan
2 Fuse/s
3 Electronicsmodule(MODAIRFLOW)
4 Spillagemonitoring device (TTB) (atrear)
5 Multifunctional control
6 LimitSwitch
7 Airflow sensor (Modairflow models)
8 Fan delay control (non modairflow models)
9 Pilot burner
10 Burner and control assembly
11 Data plate
12 Piezo unit
13 Gas connection
14 Electrical assembly
15 Time control
16 Air filter
1.1 HI-SPEC J50 is an open-flued, fan assisted downflow, ducted warm air heater, which may be supplied with MODAIRFLOW
control and in combination with an ELJAN 6 water circulator.Anon-MODAIRFLOW version is available as an option.
ASpillage Monitoring Device (TTB) is fitted which senses the temperature in the draught diverter, and shuts down the
appliance when this temperature rises due to the presence of flue gases.
1.2 The air heater output can be adjusted between 11.72kW (42.2MJ/h, 40,000Btu/h) and 14.65kW (57.75MJ/h, 50,000Btu/h).
“Summer air circulation” of unheated air is available by manual selection (see User’s Instructions). ELJAN 6 output is 3.32kW
(11.5MJ/h,11.340Btu/h).
THISAPPLIANCECONFORMSTOBSEN45014
Installation shall be in accordance with the current editions of:
Building Standards (Scotland) (Consolidation) Regulations
Building Regulations
Gas Safety (Installation and Use) Regulations (as amended)
BS7671 Institute ofElectricalEngineers (I.E.E)Wiring Regulations
BS 6891 Installation of Low Pressure Gas Pipework of up to 28mm (R1) in domestic premises (2nd family gases).
BS 5440 Pt. 1 (Flues for GasAppliances)
BS5440Pt. 2 (Air Supplyfor GasAppliances)
BS 5864 Installation of Gas Fired DuctedAir Heaters
Model and LocalAuthority Bye-laws
This appliance has been tested and certified for use with natural gas
1. BRIEFDESCRIPTION
These instructions are to be left with the User or adjacent to the Gas Meter
Johnson and Starley prides itself on its ability to supply spare parts quickly and efficiently. If you
have a problem in obtaining a spare part, please contact Johnson and Starley Spares Department at
the address below.
JOHNSON & STARLEY LTD.
Telephone: [phone] Rhosili Road,
Brackmills,
Fax:[phone] Northampton NN4 7LZ
Publication No. ZZ 851/6
October 2006
HI-SPEC J50 WARM AIR HEATERS
with MODAIRFLOW and non-MODAIRFLOW Control
INSTALLATION, COMMISSIONING& SERVICINGINSTRUCTIONS
G.C. No 42 451 13

231
NOTES:
IMPORTANT:STATUTE LAWDEFINESTHATALLGASAPPLIANCESMUSTBE INSTALLEDBYCOMPETENT
PERSONS, (i.e. CORGI REGISTERED INSTALLERS) INACCORDANCE WITHTHE GAS SAFETY
(INSTALLATIONAND USE) REGULATIONS(CURRENTEDITION).FAILURETOCOMPLYWITHTHESE
REGULATIONS MAYLEADTO PROSECUTION.
2. HEATERCOMPARTMENTANDCLEARANCES (SEE BS 5864)
2.1 IMPORTANT: If the heater is to be fitted to an existing base duct (warm air plenum), always ensure that installation is carried
out such that the rear left hand corner of the heater is aligned with the rear left hand corner of the base duct, so that any
overhang or blanking off will be at the front and/or right hand side. In any event, blanking plates must be mechanically
secured and all joints sealed.
2.2 When the heater is fitted into a compartment, a minimum clearance from the compartment walls of 25mm (1in) at the sides, rear
and front must be left. Consideration should also be given to the space required for the removal and replacement of the filter
tray and the entry of the gas and electrical supplies.
2.3 For service access, a minimum of 450mm (18ins) is required at the front of the heater. Space must also be allowed, in a
compartment installation, to permit the removal of the heater. The clearance between the appliance and the compartment
should not be less than 75mm (3in). However, where clearances are less than 75mm, the internal surface of the compartment
must be lined with non-combustible material. The compartment must be of a fixed rigid structure.
2.4 In airing cupboard installations, the part used as the air heater compartment must comply with the relevant section of BS 5864
and must be completely separated by either a non-combustible partition or a perforated metal partition with the perforations
not exceeding 13mm (1/2in). The secondary flue must be a tight fit where it passes through the partition and must be suitably
protected(see BS 5440:Part 1).
2.5 In under-stairs installations, the compartment must comply with the relevant section of BS 5864, provided that in addition, all
internal surfaces, including the base, are non-combustible or lined with non-combustible material. This requirement is
applicable only to dwellings of more than two storeys.
2.6 In slot fit installations (see instructions packed with Slotfit Kit TS50), the slot fit compartment must comply with the relevant
section of BS 5864. Side and rear clearances should be not less than 25mm (1in).
Important: Ensure that the rear of the heater is at no time subjected to air pressure subject to leaks from underfloor, joists or
roof spaces.
2.7 In freestanding installations (see instructions packed with Top Closure Kit TCS50), only one or two walls will be in close
proximity to the air heater; these must be non-combustible in compliance with the relevant section of BS 5864.
2.8 If the appliance is to be installed onto a combustible surface, a suitable base tray (BT50 ) is required. However, when a base
duct is used, this provides sufficient protection for combustible material and no further insulation is required.
2.9 For Slot Fix applications (see instructions packed with the Slot Fix Kit), it is important to ensure that the draught diverter relief
is maintained on both sides of the application.
3. VENTILATIONANDCOMBUSTIONAIR
3.1 The room or internal space in which the heater is installed requires a permanent air vent of minimum effective area 81cm2
(12in2). The air vent should be either direct to outside air or to an adjacent room or internal space (other than a toilet or
bathroom) that itself has an equivalent air vent direct to outside.
3.2 Combustion air may be introduced, via a 120mm (5in) nominal bore pipe, connected to a return air duct or plenum from a
ventilated area and fitted with a lockable damper. The damper should be adjusted to control combustion airflow to 0.0137m3/s
(29cfm),(i.e. 1.11m/s [220ft/min] velocityin a 120mm[5in] bore pipe).If this arrangement isused, a non-closeablewarm air
register MUST be provided in the same area as the front of the air heater or heater compartment if a return air grille is not
located in that area.
3.3 When installed in a compartment, two permanent ventilation openings into the compartment are required, one at high level
and one at low level, both communicating either directly with outside air or with a ventilated room or space. The minimum
effective areas specified inTable 1 are related to the rated heat input of the Air Heater, and assuming that an ELJAN 6
circulator is fitted.
3.4 If any room or area from which air is drawn for ventilation or combustion contains an extract fan, the permanent vents must be
sized to ensure that the operation of the appliance(s) at full rate is/are not adversely affected.A spillage test as specified in
sub-para 6.8 (Safety Checks) is carried out and any remedial work undertaken.

330
4. DUCTSYSTEM
(See British Design Manual - Gas fired WarmAir Heating)
4.1 RETURNAIR
4.1.1 All return air shall be POSITIVELYducted from outside the compartment to the top of the unit via a return air duct or, if
appropriate, using a Side ReturnAir Kit SR50, and mechanically secured. It is recommended that the return air duct not
be routed directly from the main living area, but from a convenient central area serving the remainder of the dwelling.
4.1.2 The return air system should be constructed of fire-resistant material. The flue shall not be run through an area serving
as a return air path. It is extremely important that the correct size of return air grilles and ducting is used. For heaters on
maximum output the return air duct size should not be less than the equivalent of 300mm x 250mm (12" x 10"). If flexible
duct is used the duct diameter should not be less than 350mm (14") dia. The return air grille should have a free area of
not less than 1266cm2(196in2).
4.1.3 An adequate and unobstructed return air path is essential from areas not served by a directly ducted return and to
which warm air is delivered.All such rooms should be fitted with relief grilles which have a free area of 0.0088m2/kW
(1in2/250Btu/h) of heat supplied to the room. The only exceptions are kitchens, bathrooms and WC.’s.
4.1.4 The return air duct should allow for ease of removal for access to the flue.
4.1.5 All duct work in the room or internal space in which the heater is installed shall be mechanically secured, and sealed
with ducting tape.
4.2 WARMDELIVEREDAIR
4.2.1 All duct work, including riser ducts, should be fully insulated with 50mm (2in) fibreglass or similar. If short extended
duct runs are taken below floor level these should be similarly insulated, and in addition wrapped with a sound vapour
proof barrier, and protected from crushing.
4.2.2 The duct system should be carefully designed to suit the needs of its specific heating requirements and building
layout. The type of duct system, (i.e. radial/extended plenum/stepped) should be installed using the least number of
fittings to minimise airflow resistance. The base duct, which equalises the air pressure to supply ducts, shall be
constructed to support the weight of the heater, which shall be secured to the plenum with screws on at least two
sides, and sealed using self-adhesive foam strip, ducting tape or sealing compound. All ducting and blanking plates
shall be mechanically secured and sealed.
5. INSTALLATIONREQUIREMENTS
Note: For ELJAN 6 circulator Installation Instructions, see separate instructions ZZ778.
5.1 FLUES(see British StandardsBS 5440 Pt.1 Flues)
5.1.1 All joints shall be soundly sealed.
5.1.2 The flue should be kept as short and warm as possible.
5.1.3 Sufficient support brackets shall be installed to bear the weight of the total flue system.
5.1.4 The spigot connection of the heater draught diverter will accept internally the spigot end of a non-asbestos flueto BS
567or twinwall metalflue toBS 715ofnominal 100mm(4in) diameter.
5.1.5 A split collar should be fitted to provide for flue maintenance or inspection.
5.1.6 The flue shall be in accordance with the Building Regulations and British Gas Materials and Installations specification
3rd edition) with regard to clearance and shielding from combustible materials.
NOTES:
Table 1
Minimum EffectiveAreas

4
SERVICEINTERVALRECORD
It is recommended that your heating system is serviced regularly and that your service engineer completes the appro-
priate service interval record below.
SERVICEPROVIDER
Before completing the appropriate service interval record below, please ensure that you have carried out the service
as described in the heater manufacturer’s instructions and in compliance with the Gas Safety Regulations
SERVICE1 Date . . . . . . . . . . . . . . . . . .
Engineer’sName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CompanyName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tel No . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CORGIIDSerialNo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE2 Date . . . . . . . . . . . . . . . . . .
Engineer’sName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CompanyName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tel No . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CORGIIDSerialNo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE3 Date . . . . . . . . . . . . . . . . . .
Engineer’sName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CompanyName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tel No . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CORGIIDSerialNo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE4 Date . . . . . . . . . . . . . . . . . .
Engineer’sName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CompanyName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tel No . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CORGIIDSerialNo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE5 Date . . . . . . . . . . . . . . . . . .
Engineer’sName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CompanyName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tel No . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CORGIIDSerialNo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE6 Date . . . . . . . . . . . . . . . . . .
Engineer’sName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CompanyName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tel No . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CORGIIDSerialNo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE7 Date . . . . . . . . . . . . . . . . . .
Engineer’sName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CompanyName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tel No . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CORGIIDSerialNo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE8 Date . . . . . . . . . . . . . . . . . .
Engineer’sName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CompanyName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tel No . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CORGIIDSerialNo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE9 Date . . . . . . . . . . . . . . . . . .
Engineer’sName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CompanyName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tel No . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CORGIIDSerialNo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE10 Date . . . . . . . . . . . . . . . . . .
Engineer’sName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CompanyName . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Tel No . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CORGIIDSerialNo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
When all of the above services have been completed, please contact your service engineer for an additional
servicerecordsheet.
5.1.7 All materials shall be in accordance with Building Regulations requirements.
5.1.8 The flue should run as vertically as possible. Horizontal runs should be avoided if at all possible and any directional
change should be as gentle as possible. If there is any doubt about the flue configuration, the equivalent flue height
should be determined (see 5.1.11).
5.1.9 If the appliance to be fitted is a replacement, the old appliance should be checked for signs of spillage prior to
commencement of the installation and appropriate action taken, (i.e. check flue system and renew as necessary).
5.1.10 It is recommended that at least 600mm of vertical flue should be provided from the top of the draught diverter (for new
installations this shall be incorporated into the flue design). However, when carrying out replacement installations, an
existing flue system may be encountered, where the vertical flue above the appliance to the first bend is less than
600mm. In the first instance, the installer must judge whether this distance can be achieved practicably by some means.
Where this is not practicable, the existing flue system may be used, providing there is no evidence of spillage from the
old appliance (see 5.1.9 above). Every effort must be made, however, to ensure that the existing flue complies in every
other way to BS 5440 Part 1, including the visual inspection, flue flow and spillage test described in 4.3.2 of the above
standard. Flue configurations may be assessed in terms of equivalent vertical height - details are given in 5.1.11. For air
heaters, the minimum equivalent vertical height is 1 metre. The installer must make a judgement based on his
knowledge and experience and the examination and testing described above as to whether an existing flue system can
be used.
Note: Ventilation of the compartment, room or internal space in which the appliance is to be installed must be checked for
compliance with the requirements of BS 5440 Part 2 ( Ref. Section 3 of these instructions) and upgraded as necessary.
5.1.11 Calculationmethod forfluesizing: (fromBS 5440:Part1,AppendixA)
a. This appendix provides a procedure for estimating whether a given flue design is likely to ensure full clearance of
combustion products.
b. The procedure is based on calculating the ‘equivalent height’ of the flue under consideration, (i.e. that height of the
straight vertical circular flue pipe of specific size which will produce the same flow rate as the flue under
consideration). The equivalent height is calculated from the formula:
(Ki+ Ko )e
He= Hax ____________________
(Ki+ Ko)a- KeHa+ Sum K
where:
Heis the height of the equivalent flue;
Ha is the vertical height of the actual or proposed flue;
Kiis the inlet resistance of the flue;
Ko is the outlet resistance from the flue;
subscript e refers to the equivalent flue diameter;
subscript a refers to the actual or proposed flue diameter;
Keis the resistance per unit length of the equivalent flue;
Sum K is the resistance (other than the inlet and outlet resistance) of the actual or proposed flue.
Note:K and Sum K are obtained from Table 2. Koand Kiare obtained from Table 3.
c. Table 2 gives resistance factors for common flue components for use in the formula. Table 3 contains the appropriate
inlet and outlet flue resistances, (theflueis likely to be satisfactory if its equivalent heightexceeds1m).
d. WorkedCalculationExample:
A warm air unit with a 100 mm diameter flue spigot, fitted with a pre-fabricated flue system leading to a ridge tile in the loft (refer Fig.
2):
Fromtable3:
Kia Inlet resistance of actual flue =2.5
Koa Outlet resistance of actual flue =2.5
Kie Inlet resistance of equivalent flue =2.5
Koe Outlet resistance of the actual flue =2.5

528
Fromtable2:
Other resistances of actual flue:
Terminal =2.5
Pipebend ( 2x 0.61) =1.22
Pipe (4x1m @0.78) =3.12
(5x0.3m @ 0.78) =1.17
SumK= 8.01
Equivalent height:
Fromthe formula
(2.5 + 2.5)
He= 6.2 x ______________________
(2.5 + 2.5) - (0.78 x 6.2) + 8.01
He= 3.793 This flue exceeds 1.0m equivalent height and is therefore satisfactory.
Table3
Inletand outletresistance
Table2
Resistancefactorsfor use in calculatingequivelentlengths
WARM AIR UNIT
HOTWATERGENERATOR
CONTROLS to comply with the Building Regulations, each section must have a tick on one or other of the boxes
FORWARMAIR HEATERSONLY
Has the system been balanced in accordance with the heater manufacturer’s instructions? YES NO
Was an anemometer used? YES NO
Have balancing dampers been fitted? YES NO
FORWARMAIRHEATING: MEASUREANDRECORD
Burner operating pressure Mbar
Heat input KW
Temperature differential between return air inlet and nearest outlet oC
FORHOTWATERGENERATORS:MEASUREANDRECORD
Burner operating pressure Mbar
Heat input KW
Water flow temperature oC
FOR ALL PRODUCTS
Does the heating & hot water system comply with the appropriate building regulations? YES NO
Has the appliance and associated controls been installed & commissioned in accordance with manufacturer’s instructions? YES NO
Have you demonstrated the operation of the appliance & system controls to the customer? YES NO
Have you left all the manufacturer’s literature with the customer YES NO
Competent person’s signature . .. . .. . . . .. . . . .. . .. . . . .. . .. . .. . .. . . .. . .. . .. . Customer’s Signature .. .. . .. . .. . .. . .. . . .. . .. . .. . .. . .. . . .. . .. . .. .
(To confirm demonstration of equipment & receipt of appliance instructions)
COMMISSIONING ENGINEER’S DETAILS
Name .............................................................. . ... . ... . . ... . ... . Commissioning Date .. . . ... . ... . . ... . ... . . ... . ..
Address .. .. . .. . .. .. . .. . .. .. . .. .. . .. . .. .. . .. . .. .. . .. .. . .. . .. .. . .. . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tel No . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CORGI REGISTRATION No . ... . . ... . . ... . . ... . . ... . . ... . . ... . . .... . .... . .... . . .. . . . . . . . CORGI ID SERIAL No . . . . . . . . . . . . . . . . . . . . . . . . . . .
BENCHMARKNumber
WARM AIR HEATER AND CIRCULATOR
COMMISSIONING CHECKLIST
APPLIANCE SERIAL NUMBER: .. . ..... . . . ..... . . . ..... . . . ..... . . . ..... . . . ...... . . . . . . ... NOTIFICATION No: .. . . . . ........ . . . . . ........ .
APPLIANCE SERIAL NUMBER: .. . ..... . . . ..... . . . ..... . . . ..... . . . ..... . . . ...... . . . . . . ... NOTIFICATION No: .. . . . . ........ . . . . . ........ .
REQUIREMENT
1. Time & temp control to heating
2. Time & temp control to hot water
3. Heating zone valves
4. Thermostatic Radiator Valves
5. Boiler interlock
MEASURES PROVIDED
Room stat & integral timer
Cylinder stat & Integral timer
Fitted Not Required
Fitted Not Required
Provided Not Required

627
1.6m
4.6m
Ha=6.2m
RidgeTerminal
2x 300mm lengths
4x 1000mmlengths
45Obend
45Obend
2x 300mm lengths
300mmlength
Flue spigot
100mm diaflue pipe
Fig. 2
Worked example of equivalent flue height
5.1.12 Where flue blocks are used, builders should ensure that no obstruction is created during erection. The installer should
ensure that the connection flue does not project beyond the internal wall of the flue blocks and that there is provision
for examination and servicing.
5.1.13 Important: Before installing the appliance, carry out a visual check of the flue system as directed in the relevant
section of BS 5440 Pt. 1, then check the flue performance as follows:
a. Close all doors and windows in the room in which the appliance is to be installed.
b. Introduce some heat into the flue, using a blow torch or other means.
c. Carry out a flow visualisation check with a smoke pellet at the intended position for the appliance. Ensure that
there is discharge of smoke from the correct terminal only, and no spillage into the room. Smoke coming out of
other than the correct terminal only, or a down draught or ‘no flow’condition, indicates that the flue has failed
the test, and the appliance shall not be connected until the defect has been found and rectified, and the test
satisfactorily completed.
10. SHORTLISTOFSPARES
ITEM G.C. MAKER’S DESCRIPTION QTY
No No No
1 382 758 1000-0500725 Fanassembly 1
2 E02-417 B502-0182000 Filtertray assembly 1
3 244 985 CL30-0500000 TimecontrolCL3 1
4 244 986 1000-0000040 Timecontrolcover 1
5 384 739 BOS00105 Overheat(limitControl) 1
HoneywellL4069C
6 393 412 BOS01301 Multifunctionalcontrol 1
HoneywellV8600C
7 232 903 BOS02061 Sealingring(foritem6) 2
8 244 880 BOS02397/4 Pilotassembly 1
9 392 935 1000-0705140 PilotInjector 1
10 E02-418 1000-0705260 PilotFeedPipe 1
11 386-820 1000-0703870 Thermocouple 1
12 386 775 BOS01970 Electrode 1
13 397 819 BOS02394 Electrodelead 1
14 244 898 BOS02406 ElectrodeNut 1
15 E02-419 B502-0502000 SpillageMonitoringDevice(TTB) 1
16 E02-420 B502-0700000 BurnerandControlsAssembly 1
17 E02-421 1000-0705280 BurnerandCrossLighterAssembly 1
18 398-351 1000-0700980 Main InjectorBray Cat23/600 2
19 E02-422 1000-0705340 CrossLighting Injector(Bray) 1 or
E02-423 1000-0705310 CrossLightingInjector(Stereomatic) 1
20 E02-424 B502-0300005 HeatExchangerexchangekit 1
21 395 945 1000-0700570 Piezo Unit 1
22 244 971 B300-0706000 Igniter Bracket 1
23 244 957 1000-2500010 Rope RingSeal(forheatexchangercap) 1
24 245 067 B500-0380005 Draught DiverterAssembly 1
25 E02-425 B502-0161000 LowerCompartmentDoor 1
MODAIRFLOW MODELS
26 E02-545 B502-0156000 FanCompartmentDoor 1
27 245 080 B500-0530005 ControlPanelwithTransformer 1
28 245 081 1000-0500880 Wiring Harness 1
29 245 191 R005 ElectronicsModule 1
30 230 496 S00076 AirflowTemperatureSensor 1
31 244 933 1000-0514230 Fuse1A, (T) 2
32 386 475 BOS01242 Thermista-stat 1
33 E02-433 1000-0516870 Transformer 1
NON-MODAIRFLOW MODELS
34 E02-427 B502-0157000 FanCompartmentDoor 1
35 245 040 B500-0500730 ControlPanel 1
36 245 045 1000-0500870 Wiring Harness 1
37 385 159 BOS00104 FanControlHoneywellL4068C 1
38 245-509 1000-0513820 Fuse 3.15A,(T) 1

26 7
Fig.8
PrincipalDimensions
5.2 ELECTRICAL
5.2.1 Mains.
a. The heater is supplied with mains cable (PVC sheathed, heat resisting to 85oC), 3-core Brown-Blue-Green/Yellow,
6A, 0.75mm2), connected to a terminal block and exiting through the heater at the right hand top front. The cable
is suitable for a 230V 50Hz supply and shall be connected to the fixed wiring using a double pole switched,
fused spur, incorporating a protective earth link.The fuse fitted shall be rated 5A to BS 1362. Connections shall
be in accordance with the current edition of I.E.E Regulations BS 7671.
b. MODAIRFLOW Models:An electronic control (Thermista-stat) is supplied which acts as a room thermostat.
c. Non-MODAIRFLOWmodels:A24Vroomthermostat (not supplied),that complies with BS800, BS 3955 andBS
4201 is essential to ensure close control of comfort conditions. An anticipator is located within the thermostat
and is graded in amps. The anticipator should be checked and adjusted to 0.2A.
5.2.2 Thermista-stat/Room Thermostat and its location.
a. The Thermista-stat/Room Thermostat should be located where there is free air circulation approx. 1.5m (5ft) from
the floor.
b. Avoid the following locations:-
i) In a room where temperature is greatly affected by the sun or any other heat source, e.g. radiant fire, wall
light fittings or TV set.
ii) Near an outside door or windows, or on an outside wall.
iii) Where affected by warm air ducts, diffusers, waste pipes or the heater itself.
iv) Where subject to vibration.
c. For MODAIRFLOW models, connect Thermista-stat wires to control panel terminals ‘4’ and ‘5’ (see Fig. 5a and
6a), connection polarity being important, connect +ve side on control panel to +ve side on Thermista- stat.
d. For non-MODAIRFLOW models, connect room thermostat wires control panel terminals ‘16’ and ‘17’
5.3 GAS(SEEBS5864ANDBS 6891)
5.3.1 An independent gas supply pipe from the meter is to be preferred wherever possible. When this is not possible, the
pipe must be capable of taking the complete input of the heater and all other gas appliances being served by this same
pipe. This supply should be suitably sized to conform to British Standards requirements of no more than 1.0 mbar (0.4in
wg) pressure drop (See table of discharge in BS 6891).
5.3.2 The 1/2in union gas cock (supplied) must be fitted to the gas inlet of the heater for easy isolation during servicing. The
gas pipe should be fitted and installed so that it is durable, substantial and gas tight. To assist in determining whether
a gas connection may not be tight, a leak detection fluid should be applied around the connection. Under no
circumstances should a flame be used to locate a gas leak. Gas entry to the air heater is through either side to a Rc1/2
(1/2in BSP. external [taper] thread).
5.4 DRAUGHTDIVERTER&DEFELCTORPLATE:
5.4.1 The HI-SPEC J50 heater is supplied with a draught diverter which houses the TTB, and which requires fitting to the
rear of the heater prior to installation, using 6 x 4mm screws and lock washers (provided). Connect the TTB to the
terminal block situated on the rear upper left hand corner of the appliance.
5.4.2 The deflector plate prevents spillage from the draught diverter in the event of a leak between the air heater and the
base plemum and MUST be fitted as shown in fig 3 using the screws provided.
5.5 DEFLECTORPLATESAFETYCHECK:
In order to ensure that the deflector plate is preventing warm air from entering the draught diverter and therefore causing spillage, the
followingtest MUST be carriedout BEFORE commissioning:
5.5.1 Turn on the power supply to the heater.
5.5.2 Set the summer airflow switch to “on”.
5.5.3 Using a smoke match, introduce smoke into the heat exchanger at the burner opening.
5.5.4 Ensure that the smoke is drawn into the heat exchanger and not blown back from the burner opening.
5.5.5 If smoke is blown back from the burner opening, check for air leaks between the heater and the base plenum,
paying particular attention to the rear of the heater directly beneath the draught diverter.

258
130mm
HEATER
DEFLCTORPLATE
Fig.4
PilotBurnerAssembly
Thermocouple PilotBurner
Electrode
Fig.7b
Non-ModairflowFunctionalDiagram
6. COMMISSIONING
6.1 PREPARATION:
6.1.1 Ensure that:
a. Gasand Electricalsupplies are OFF.
b. Filter, fan and fan compartments are free from
obstructions.
c. All registers or grilles are open and conform to
design specifications.
d. Return, relief and ventilation air installations are
adequate.
6.1.2 SETTINGFANSPEED(NONMODAIRFLOWMODELSONLY):
6.1.2.1 Remove air filter and chamber door.
6.1.2.2 Ensure fan control is set to “100o” OFF and “40o” DIFF
6.1.2.3 Ensure overheat (limit) control is set to “200oF” This control is not to be set to any other setting!
6.1.2.4 Refit fan chamber door and air filter.
6.2 SYSTEMBALANCING:
6.2.1 Set theAir Heater electrical supply ON.
6.2.2 Setthe ‘SUMMERAIRCIRCULATION’switchto ‘ON’.
6.2.3 Balance the ducting system to provide the required volume proportions at the
warmair outlets.
NOTE: If the system includes ceiling diffusers, air velocities through these should be NOT
LESSTHAN 1.5m/s (300ft/min), except forvery smallrooms (i.e., bathrooms
etc.). Outlet faces may require partial blanking in order to achieve this.
6.2.4 Setthe ‘SUMMERAIRCIRCULATION’switch to‘OFF.
6.3 IGNITIONOFPILOTANDMAINBURNERS:
WARNING: If the Pilot Burner is extinguished either intentionally or unintentionally, no
attempt should be made to relight the gas for a minimum of 3 minutes. Ensure
that the Electrical supply, Time Control and Selector switches are set to
‘OFF’.
6.3.1 Set the Thermista-stat/room thermostat to its lowest or OFF setting.
6.3.2 On the Multifunctional Control, remove the Outlet Pressure test point cover,
and a fit pressure test gauge (refer Fig. 5).
6.3.3 Turn the heater Gas supply ON, test for gas soundness and purge the whole
gas pipe as described in BS 6891.
6.3.4 Referring to Fig .5, press and hold the OPERATING CONTROL, and whilst
observing the Pilot Burner, repeatedly press the Piezo igniter button until the
Pilot Burner ignites.
6.3.5 After 20 seconds release the OPERATING CONTROL and let it spring out; ensure that the Pilot Burner remains alight.
If the Pilot Burner extinguishes, rotate the OPERATING CONTROL clockwise to the ‘l’position and ensure that the
OPERATING CONTROL is fully reset.Wait three minutes and repeat steps 6.3.4 and 6.3.5 until Pilot Burner remains
alight.
Fig. 3
DeflectorPlateFitted

924
1
2
4
Fig.5
MultifunctionalControl
1. Operating control
2. Burner PressureAdjuster
3. Outlet Pressure test point
4. PilotAdjuster
Fig.7a
ModairflowFunctionalDiagram
3
6.4.2 Apply the pressure set arrow to indicate the appropriate burner pressure on the data badge.
6.5 EXTINGUISHINGOFPILOTANDMAINBURNERS:
6.5.1 On the Multifunctional Control, rotate the OPERATING CONTROL clockwise to the ‘O’ position and ensure that the
OPERATING CONTROLfully resets, and both Pilot and Main Burners are extinguished.
6.5.2 On the Multifunctional Control, remove the pressure test gauge and refit the Outlet Pressure test point cover, and test
for gas soundness.
6.6 TEMPERATURERISECHECK:
6.6.1 Ignite the Pilot and Main Burners and allow to operate for 15 minutes to ensure stability.
6.6.2 With the Main Burner operating continually, check that the temperature rise across heater is between 45oC - 55oC,
setting the fan speed accordingly, (decrease fan speed to increase temperature rise). For MODAIRFLOW heaters,
adjusting the balancing screw sets fan speed; for non-MODAIRFLOW heaters, fan speed is adjusted by selecting the
fan speed at the control panel (decrease voltage selection to decrease fan speed).
6.3.6 Ensure that the pilot flame envelops the thermocouple tip, adjusting the PilotAdjuster as required (Refer Figs. 4 and
5).
6.3.7 Set the Heater Electricity supply ON.
6.3.8 Set the Time Control to the required Heating On periods.
6.3.9 Set the Selector switch to ‘TIMED’.
6.3.10 Set the Thermista-stat or room thermostat to MAXIMUM.
6.3.11 Ensure that the Main Burner has now ignited.
6.3.12 Test for gas leakage at the supply, Multifunctional Control, and Pilot and Main Burners using proprietary detection
fluid, sealing any leaks found.
6.3.13 Allow the heater to operate for a minimum of 15 minutes to ensure stability.
6.4 MAINBURNERPRESSURETEST:
NOTE:AIR HEATER BURNERSAREFACTORYSETTOPROVIDEANOMINALHIGHRATEOUTPUTASDETAILEDINSUB
PARA1.2
6.4.1 Referring to Table 4 and Fig. 5 below, ensure that the pressure test gauge indicates correct burner pressure, resetting
if required as follows:
a. At the Multifunctional Control:
i. Remove the Burner PressureAdjuster cover.
ii. Set the Burner Pressure Adjuster to provide a pressure test gauge indication for the correct burner
pressure as detailed in Table 4.
iii. Refit the Burner PressureAdjuster cover.

10 23
Fig.6b
Non-ModairflowCircuitDiagram
Note:Tapping1 =150V,TAPPING2 =170V,TAPPING3=190V,TAPPING4=210V,TAPPING5= 230V.
6.7 AUTOMATICCONTROLSCHECK:
6.7.1 Setthe TIMECONTROL to ‘ON’.
6.7.2 Turn the Thermista-stat or room thermostat slowly clockwise until the Main Burner ignites.
6.7.3 Ensure that the fan starts to operate after a short period (approx. 1-2 minutes).
MODAIRFLOWmodels:
6.7.4 Ensure that the fan speed increases to full speed.
6.7.5 When the temperature reaches the control setting, check that the Main burner cycles ON and OFF, at approximately
75 to 120 seconds.
Non-MODAIRFLOWmodels:
6.7.6 When the temperature reaches the control setting, ensure that the Main Burner extinguishes followed by the fan
switching off after a short period.
6.7.7 When the temperature falls below the control setting, ensure that the Main Burner re-ignites followed by fan
operation.
6.8 SAFETYCHECKS:
6.8.1 Check for gas soundness within the appliance.
6.8.2 Spillage test: Carry out a full spillage test as follows, and ensure that the flue operates effectively with all doors
closed and any extractor fans in operation.
NOTE: If an extractor fan is situated in an adjoining or adjacent room, carry out the spillage test with the interconnecting doors
open.
Ifthe draughtdiverteris accessible:
a. Introduce smoke into the draught diverter adjacent to an exit from the heat exchanger, by means a smoke match or
puffer.
b. Ensure that there is no spillage present (indicated by displacement of smoke downwards and out of the draught
diverter).
Ifthe Draught Diverterisnot accessible:
a. Introduce smoke, by means of part of a smoke pellet on a non-combustible support, into the heat exchanger.
b. Extinguish the Main and Pilot burners.
c. Ensure that there is no spillage evident by visually observing the draught diverter location on the air heater.
d. If spillage is evident, further investigation and rectification is required before re-testing the appliance.
e. Repeatspillagetestsbut withthe fanrunning,orSummerAirflowswitch setto ON.
WARNING:The appliance shall not be left connected to the gas supply unless it has successfully passed the spillage test.
6.8.3 Turn OFF the gas supply at the service cock and ensure that the Multifunctional Control fail-safe operates within 60
secs (indicated by loud click from Multifunctional Control).
Table 4
Main Burner Pressure Settings

1122
mbar in.wg.
0.50 0.20
0.375 0.15
0.25 0.10
RESISTANCEEXTERNALTOHEATER
Response
Area
Table 5
Fan PerformanceCurve
350 400 450 500 550 600ft3/min
0.165 0.189 0.212 0.236 0.256 0.283m3/sec
AIR VOLUME
Fig.6a
ModairflowCircuitDiagram
6.8.4 Turn the gas supply ON at service cock.
6.8.5 Switch the appliance electrical supply OFF.
6.8.6 Disconnect the fan at the flying socket
6.8.7 Switch the appliance electrical supply ON.
6.8.8 Ignite the Main and Pilot Burners as detailed in sub para 6.3.1 to 6.3.5
6.8.9 Ensure that the Limit Switch operates, indicated by the Main Burner extinguishing, within 120 and 180 seconds.
6.8.10 Switch the appliance electrical supply OFF.
6.8.11 Reconnect theAir Heater Fan.
6.8.12 Switch the appliance electrical supply ON.
6.8.13 Ensure that the Main Burner re-ignites when the appliance temperature reduces, (note: with the fan disconnected, there
may be some delay before the Main Burner re-ignites).
7. INSTRUCTIONSFORUSERS
7.1 If the building is unoccupied, ensure that the Instructions for the User are left taped to the air heater, and that the Installation,
Commissioning and Maintenance Instructions are left at or near the air heater for use on future service calls.
7.2 If the building is occupied, hand the User Instructions over and ensure the User understands:
7.2.1 How to ignite the Pilot and Main Burners.
7.2.2 How to operate the Thermista-stat/room thermostat, time and heater ON/OFF switch and summer air circulation switch,
and that the time control must be reset following a power failure.
7.2.3 How to extinguish the Pilot and Main Burner at the Multifunctional Control, and switch off the electrical supply to the
heater.
7.2.4 How to remove, clean and refit the air filter and at what intervals (i.e. fortnightly, or weekly for new houses.)
7.2.5 How to control the heating system by opening and closing warm air outlets.
7.2.6 How to obtain summer air circulation.
7.2.7 That the air grilles on the heater or heater compartment; grilles and ventilators in the walls, windows or doors of the
building must not be obstructed.
7.2.8 That the heater must be serviced at least once a year by a competent person to ensure efficient and safe operation.
7.2.9 That the red instructions for safe use have been pointed out and understood.
7.2.10 That expert help must be obtained if persistent failure of the pilot burner occurs.

12 21
CHECKFANSELECTOR
SWITCHSETTING
SETFANSELECTOR
SWITCHTO
AUTO
N
Y
IS
SWITCHSET
TOAUTO ?
CHECKSUMMERAIR
CIRCULATION
SWITCH
IS
SWITCHSET
TOOFF ?
DOES
FANSTILL
RUN?
DOES
FANSTILL
RUN?
SETFANSUMMER
AIRCIRCULATION
SWITCHTOOFF
N
Y
Y
Y
DOES
FANSTILL
RUN?
DISCONNECTAIRFLOW
SENSOR
Y
DOES
FANSTILL
RUN?
REPLACE
ELECTRONICS
MODULE
Y
IS
PILOTFLAME
TOO
BIG?
N
YADJUSTPILOT
FLAMETOCORRECT
SETTING
REPLACE
AIRFLOWSENSOR
N
FANCONTINUESTORUNAFTER HEATINGISTURNEDOFF
8. MAINTENANCE
IMPORTANT: Ensure that the gas and electricity supplies are isolated before commencing any maintenance or replacement of
components. After completion of any maintenance, always test for gas soundness and carry out a complete functional test of the
appliance in accordance with the Commissioning Instructions at Sect 6.1 to 6.8 inclusive.
8.1 ROUTINEMAINTENANCE:
8.1.1 Operate the appliance and check for the correct function of the burner and controls.
8.1.2 Turn OFF the gas and electrical supplies to the appliance.
8.1.3 Remove the air heater front panel.
8.1.4 Remove and check the return air filter/cleaner for debris, remove and clean theAir Circulation fan as detailed at S 8.8.
8.1.5 Remove the Burner and ControlsAssembly as detailed in para 8.2. Inspect and clean the main burner and injector as
necessary. Examine the main burner for cracks, including hairline cracks, exchanging the burner as necessary.
8.1.6 Inspect and clear the pilot burner orifice.
8.1.7 Clean the heat exchanger flueways by thoroughly brushing from above and below.
8.1.8 By viewing through the FanAperture, and using a torch or similar, examine the heat exchanger externally for signs of
cracks or holes, particularly around welded joints.
8.1.9 Using a torch or similar, introduce a light source into the heat exchanger burner aperture and upper access port, and
again examine the heat exchanger for signs of cracks or holes, particularly around welded joints, whilst again viewing
through the Fan Aperture.
8.1.10 Refit theAir Circulation fan, Burner and ControlsAssembly, and air filter/air cleaner.
8.1.11 Light the appliance and note the main burner flame profile. If the flame profile is affected when theAir Circulation fan
switches on, check for any air leaks between the air heater and the base plenum, paying particular attention to heaters
with rear draught diverters. Rectify any air leaks before continuing with this procedure.
8.1.12 Allow the air heater to operate for approximately 15 minutes to ensure stability and, with the main burner lit, ensure
that the operation ofAir Circulation fan does not affect the main burner flame profile.
8.2 BURNERANDCONTROLASSEMBLYREMOVAL:
8.2.1 Ensure that the Gas and Electrical supplies are switched OFF
8.2.2 Remove the appliance lower front door.
8.2.3 Disconnect the igniter at the Piezo unit.
8.2.4 Disconnect the Multifunctional Control electrical connection.
8.2.5 Disconnect the water heater (if necessary).
8.2.6 Disconnect the gas supply by breaking the union at the input side of the Multifunctional Control.
8.2.7 Remove 6 x BurnerAssembly fixing screws and withdraw the BurnerAssembly.
8.2.8 Refit the Burner and ControlAssembly in reverse order, ensuring that the spillage baffle above the BurnerAssembly
contacts the top of each burner arm.
8.3 MAINBURNERASSEMBLYCLEANING:
8.3.1 Remove the Burner and ControlAssembly as detailed in 8.2.
8.3.2 Cleantheburner thoroughly both insideand out with asoft brush.DO NOTENLARGE,DISTORT ORDAMAGE
BURNERHOLES.
8.3.3 Reassemble in reverse order.
8.4 MAININJECTORSREMOVAL,CLEANINGANDREPLACEMENT:
8.4.1 Remove the Burner and ControlAssembly as details in 8.2
8.4.2 Remove 2 x screws securing the Pilot Burner assembly to the Burner and ControlAssembly and withdraw the Pilot
Burner assembly, taking care to avoid damage to the thermocouple capillary.
8.4.3 Remove 2 x screws securing the Burner arm to the Burner and ControlsAssembly, and withdraw the BurnerArm.
8.4.4 Unscrew 2 x Main injectors, and 1 x cross lighter injector from their housings.
8.4.5 Cleanasnecessary.DONOTENLARGE,DISTORTORDAMAGEMAININJECTORHOLES.
8.4.6 If the injectors are to be replaced, ensure that they are correctly marked, referring to the Data Badge for details.
8.4.7 Refit or replace the injectors in reverse order.

1320
DEFECTISOPENCIRCUIT
INTHERMISTA-STAT
INSTALLATIONWIRING
DOES
BURNER
STAY
LIT?
YREPLACE
THERMISTA-STAT
BRIDGETERMINALSAT
THERMISTA-STAT
Y
IS
POLARITY
OK ?
NRECTIFY
CHECKTHERMISTA-STAT
CONNECTIONSPOLARITIES
Y
REPLACE
ELECTRONICMODULE
N
DOES
BURNER
STAY
LIT?
BRIDGETHERMISTA-STATAT
HEATER
Y
SETTHERMISTA-STAT
TOMAX
IS
THERMISTA-
STAT
SET TO
MAX ?
N
N
MAIN BURNER ONLYFIRES FOR SHORT PERIODS 8.5 PILOTBURNER,THERMOCOUPLEANDELECTRODE,REMOVALANDREPLACEMENT:
8.5.1 Remove the Burner and ControlAssembly as detailed in 8.2
8.5.2 Disconnect the Igniter lead from the Piezo unit.
8.5.3 Disconnect the Thermocouple from the Thermocouple adapter on the Multifunctional Control, taking care to avoid
damage to the thermocouple capillary.
8.5.4 Release the Pilot Feed Pipe from the Multifunctional Control.
8.5.5 Remove 2 x 4mm screws securing the Pilot Burner assembly to the Burner and Control assembly, and withdraw the Pilot
BurnerAssembly.
8.5.6 Release the Thermocouple securing nut from the Pilot Burner assembly and withdraw the Thermocouple, taking care to
avoid damaging the Thermocouple capillary.
8.5.7 Release the Electrode securing nut from the Pilot Burner assembly and withdraw the Electrode.
8.5.8 Release the Pilot Feed Pipe securing nut from the Pilot burner assembly and withdraw the Pilot Feed Pipe and Pilot
Injector from the Pilot Burner assembly, and disconnect the Pilot Injector from the Pilot Feed Pipe hook.
8.5.9 Refitting or replacement is in reverse order.
NOTE:WhenrefittingorreplacingThermocouple,tightenonlytoFINGERTIGHT+1FLAT.
8.6 MULTIFUNCTIONALCONTROLREMOVAL:
8.6.1 Remove the Burner and ControlAssembly as detailed in 8.2
8.6.2 Disconnect the Thermocouple at the Multifunctional Control (including the adapter), avoiding damage to the capillary.
8.6.3 Disconnect the Pilot Feed Pipe from the Multifunctional Control.
8.6.4 Disconnect the Multifunctional Control input and output supply feeds.
8.6.5 Refitting or replacement is in reverse order.
8.7 PIEZOUNITREMOVAL:
8.7.1 Disconnect 2 x conductors from Piezo unit.
8.7.2 Unscrew the Piezo retaining nut and remove the unit from its mounting bracket.
8.7.3 Refitting or replacement is in reverse order.
8.8 AIRCIRCULATINGFAN,REMOVALANDCLEANING:
8.8.1 Ensure that the electrical supply is isolated.
8.8.2 Remove the appliance lower and upper doors.
8.8.3 Disconnect the 230V connections (L/N/E) from the FanAssembly.
8.8.4 Release 4 x screws securing the control panel, and withdraw the panel, avoiding damage to wiring.
8.8.5 Release 2 x FanAssembly securing screws and withdraw the FanAssembly from the Heater cabinet, avoiding damage
to fan blades.
8.8.6 Remove all dust from the impeller and motor, avoiding damage to the fan blades.
8.8.7 Refitting or replacement is in reverse order.
8.9 ELECTRICALASSEMBLYREMOVAL:
8.9.1 Ensure that the electrical supply is isolated.
8.9.2 Remove the appliance lower and upper doors.
8.9.3 Release 2 x 4mm screws securing the Limit switch cover and the withdraw cover.
8.9.4 Release the ElectricalAssembly cable clamp,
MODAIRFLOWmodels:
8.9.5 Disconnect the following:
a. Disconnect 230Vconnections (L/N/E) from FanAssembly,
b. 230V mains ‘L’,‘N’and ‘E’from connection blockterminals ‘1’, ‘3’and‘2’respectively,
c. Thermista-stat connections from connection block terminals ‘4’ (+ve) and ‘5’ (-ve),
d. Limit Switch‘LOAD’and ‘COMMON’connections,
e. 2 xAirflow sensor connections,

14 19
FANOPERATES,BUTBURNERCYCLESBEFOREREQUIREDTEMPERATUREISREACHED
BRIDGE
THERMISTA-STAT
N
CHECK AIR FILTER &
RETURN AIR PATH FOR
RESTRICTIONS
SET FAN SELECTOR TO
AUTO & BRIDGE AIRFLOW
SENSOR
N
CHECKTEMPERATURE
RISE ACROSS HEATER IS
LESS THAN 60°c
CHECKTTB,LIMITSWITCH
&CONNECTIONS
Y
Y
CHECK MAIN
BURNER
PRESSURE SETTINGS
ARE CORRECT
SETTOCORRECT
PRESSURESETTING
N
Y
SETFAN
BALANCINGSCREW
Y
DOES
FAN
SPEED
UP?
N
Y
REPLACE
ELECTRONICMODULE
REPLACE
ELECTRONICMODULE
REPLACE
AIRFLOWSENSOR
IS
PATH
CLEAR?
NCLEARRESTRICTIONS
ANDBLOCKAGES
CHECK FAN BALANC-
ING SCREW IS
CORRECTLY SET
N
DOES
FAN
SPEED
UP?
N
Y
SET FAN SELECTOR
SWITCH TO
CONTINUOUS
DOES
BURNER
STAY
LIT?
REPLACE
THERMISTA-STAT
Y
REPLACE
ELECTRONICMODULE
N
Y
IS
OVERHEAT
CONTROL
OK?
NON-MODAIRFLOW models:
8.9.6 Disconnectthe following:
a. Disconnect 230V connections (L/N/E) from the FanAssembly,
b. 230V mains ‘L’,‘N’and ‘E’from connection block terminals ‘1’and ‘3’, and earth stud respectively,
c. Room thermostat from connection block terminals ‘5’ and ‘6’,
d. Limit switch‘LOAD’ and‘COMMON’ connections,
e. FanControl ‘LOAD’,‘COMMON’and ‘EARTH’connections,
Both model types:
8.9.7 Disconnect 2 x TTB connections.
8.9.8 Disconnect the Multifunctional Control connections.
8.9.9 Disconnect the Water Circulator electrical connections (if fitted).
8.9.10 Release 4 x 4mm screws securing the Electrical assembly to the heater cabinet and remove the Electrical assembly,
releasing wiring from cable clamps and grommets as required..
8.9.11 Refitting or replacement is in reverse order.
8.10 ELECTRONICMODULEREMOVAL(MODAIRFLOWMODELSONLY)
8.10.1 Remove the ElectricalAssembly as detailed in sect 8.9.
8.10.2 Disconnect the Electronic Module from the ElectricalAssembly.
8.10.3 Release 3 x screws securing the Electronic Module to the Electrical Mssembly and remove the module.
8.10.4 Refitting or replacement is in reverse order.
8.11 TRANSFORMERREMOVAL(MODAIRFLOWMODELSONLY):
8.11.1 Remove the ElectricalAssembly as detailed in sect 8.9.
8.11.2 Disconnect the Transformer from the ElectricalAssembly terminal block, and the fuse from the Earth stud,
8.11.3 Release 2 x screws and nuts securing the Transformer to the ElectricalAssembly, and remove the Transformer.
8.11.4 Refitting or replacement is in reverse order.
8.12 TIMECONTROLREMOVAL:
8.12.1 Ensure that the electrical supply is isolated.
8.12.2 Release the securing screw situated on the lower face of the Time Control and remove it by partially withdrawing
bottom of the Time Control and then lifting upwards.
8.12.3 Disconnect the Time Control electrical connections from its integral terminal strip.
8.12.4 Refitting or replacement is in reverse order.
8.12.5 Set the Time Control to the required ON and OFF times.
8.12.6 Set the Time Control to the correct time.
8.13 FANDELAYCONTROL,LIMITSWITCHANDAIRFLOWSENSORREMOVAL:
NOTE:Airflow sensor applies to MODAIRFLOW models only, whilst Fan Delay Control applies solely to non-MODAIRFLOW
models.
8.13.1 Ensure that the electrical supply is isolated.
8.13.2 Remove the appliance lower and upper doors.
8.13.3 Release 2 x 4mm screws securing the Limit Switch cover and withdraw the cover.
8.13.4 Disconnect the required control/switch.
8.13.5 Release 2 x securing screws and remove the required control/switch.
8.13.6 Refitting or replacement is in reverse order.

1518
8.14 SPILLAGEMONITORDEVICE(TTB)REMOVAL:
8.14.1 Ensure that the electrical supply is isolated.
8.14.2 Remove the appliance lower and upper doors.
8.14.3 Remove theAir Circulation fan as detailed in para 8.8.
8.14.4 Cover the aperture to the heat exchanger in the top shelf to prevent objects falling into the heat exchanger.
8.14.5 Release and remove 6 x screws securing the fan compartment rear access panel, and withdraw the panel.
8.14.6 Disconnect the TTB terminal block plug from the terminal block socket, situated on the compartment rear bulkhead,
remove the grommet rearwards and pass the terminal block through the aperture in the rear bulkhead.
8.14.7 Release and remove the 5mm nut and lock washer securing the TTBAssembly to the Draught Diverter, and withdraw
the TTBAssembly.
8.14.8 Refitting or replacement is in reverse order.
8.15 HEATEXCHANGERACCESS:
8.15.1 Release 2 x securing screws and remove heat exchanger access caps and gaskets.
8.15.2 Remove the heat exchanger baffles.
8.15.3 Reassembly is in reverse order.
NOTE:When reassembling,ensurethatthebaffles arepushedfullyhomeand theaccess capsarefully sealed.In theeventof
heatexchangerreplacementbeingnecessary,contact Johnsonand Starley ServiceDepartment.
9. DEFECTDIAGNOSIS
9.1 IMPORTANT:
If an electrical defect occurs after installation of the appliance; preliminary earth continuity, polarity, and resistance to earth
checks should be carried out with a multimeter. On completion of any maintenance/fault-finding task that has required the
breaking and remaking of electrical connections, then checks of continuity, polarity, and resistance to earth must be
repeated.
9.2 WARNINGS:
9.2.1 When purging or checking gas supplies, ensure that ventilation to the room or cupboard is adequate, and that all
naked lights are extinguished.
9.2.2 MODAIRFLOWmodels: Before commencing defect diagnosis, ensure that the Thermista-stat is set to maximum,
mains supply is ‘ON’ and the time control is at an ‘ON’ position.
9.2.3 Care is to be taken during the replacement and handling of electronic assemblies, (i.e., electronic panel, airflow sensor
or Thermista-stat). It is not practical to rectify defects on these assemblies, except at the manufacturer, and any
attempt to do so may render the guarantee or factory replacement arrangement invalid.
MAIN BURNER NOT OPERATING
IS
PILOT
LIT?
IS 230V
SUPPLY
ON ?
IS TIME
CONTROL &
THERMISTA-STAT
CORRECTLY
SET ?
CHECK
TERMINAL
D9 IS
18V
CHECK
TERMINAL
C8 IS
230V
CHECK
TERMINAL
C10 IS
24V
REPLACE
ELECTRONIC
MODULE
IS
GAS
ON?
NTURNGAS
ON
N
LIGHT
PILOT
Y
Y
SWITCHON
230 V N
Y
N
Y
REPLACE
FUSE
N
Y
REPLACE
MULTIFUNCTIONAL
CONTROL
SETCONTROLS
CORRECTLY
Y
N
CHECKPOLARITYOF
THERMISTA-STAT
CONNECTIONS
Y
IS
POLARITY
CORRECT?
NRECTIFY
DEFECT
Y
BRIDGE THERMISTA-STAT
TERMINALS AT HEATER
BRIDGETHERMISTA-STAT
TERMINALSATHEATER
IS
BURNER
LIT?
IS
BURNER
LIT ?
WIRINGDEFECT
BETWEENHEATER
&
THERMISTA-STAT
N
Y
N
N
Y
N
CHECKTTB,
LIMITSWITCH
&
CONNECTIONS
Y
N
CHECK230VI/P
&TIMECONTROL
OPERATION
REPLACE
THERMISTA-STAT
REPLACE
TRANSFORMER
Y
IS
FUSE
OK ?
CHECK
24V AT
MULTIFUNC-
TIONAL
CONTROL

1716
MAINBURNERNOTCYCLING
(ROOMTEMPERATURETOOHIGH)
REPLACE
MULTIFUNCTIONAL
CONTROL
N
YREPLACE
ELECTRONICS
MODULE
DISCONNECT
YELLOWWIREAT
MULTIFUNCTIONAL
CONTROL
N
DOES
BURNER
GO
OUT?
DISCONNECT
THERMISTA-STAT
REPLACE
THERMISTA-STAT
Y
DOES
BURNER
GO OUT?
N
CHECKFORVOLTAGEAT
FANLIVETOEARTH
REPLACE
ELECTRONICS
MODULE
Y
N
IS
FUSE
OK ? REPLACEFUSE
N
Y
CHECKFOR
VOLTAGE
ATFANLIVETO
NEUTRAL
MAIN BURNER ON, BUT FAN NOT RUNNING
YREPLACEFAN
DOES
FAN
START?
N
BRIDGEOUT
AIRFLOWSENSOR
YREPLACE
AIRFLOWSENSOR
REPLACE
TRANSFORMER
Remedy
Check for gas at inlet pressure test point
on the multifunctional control
Purge gas suply pip in accordance with BS
6891
Clear pilot orifice or replace pilot injector
Check igniter, lead and electrode.
Check that the mains gas pressure is 20
mbar and reduce if necessary.
Check that connection is secure.
Replace multifunctional control
Replace thermocouple
Check connections from electrical panel to
fan.
Check connections
Check for correct settings
Replace,taking carenotto damageimpeller
Replace
Check gas rate and burner pressure
setting.
Adjust fan speed or gas rate accordingly
Check that filter and air path is clear
Open additional outlets
Carry out spillage test and retify
ReplaceTTB
Check gas rate and burner pressure
settings
Check for correct settings
Check for correct settings
Check burner pressure settings
Replace fan assembly
Adjust fan speed
Consult diagnostics chart and follow
recommended procedure.
Check mains supply
Check that the time control and room
thermostat are operating correctly
Replace fuse and check for short circuits
Check connections
Check with test meter/replace if necessary
Replace
Short cicuit switch & replace if necessary
Fit temporary loop in heater thermostat socket.
Ifheaterignitescheckexternalcircuit.
Possible Cause
1) No gas to the heater
2) Gas supply not purged
3)Pilot orifice restricted
4) Piezo system faulty.
5) Excessive gas supply pressure
1) Connection between thermocouple and
mutifunctional control not secure
2) Faulty power unit multifunctional
control
3) Faulty thermocouple
1) No voltage to fan
2) Loose electrical connection on fan
delay control
3) Fan delay control set incorrectly
4) Faulty fan assembly
5) Faulty fan delay control
1) Gas rate or burner pressure setting
high
2) Temp rise excessive
3) Air filter or return air path restricted.
4) Excessive number of oulets closed
5) Spillage of flue gases.
6) Spillagemonitoringdevice(TTB) faulty.
1) Gas rate or burner pressure setting too
low
2) Fan delay control set incorretly
1) Fan delay control set incorrectly
1) Gas pressure too high
2) Noisy fan motor
3) Fan speed setting too high
1) Fault related to Modairflow Control
system.(See relevant pages)
1) Mains electrical suply not connected
to heater.
2) No demand for heat
3) 3A fuse failed
4) Loose connection to rom thermostat,
limitswitch, Multifunctional Control
lead,Time Control or transformer
5) Transformer open circuit
6) Multifunctional Control faulty
7) Limit switch Faulty
8) Room thermostat/external wiring faulty
or room thermostat faulty
Symptom
A) Pilot will not light
B) Pilot lights but goes out on releasing
START button during initial light-up,
or after normal operation.
C) Main burner lights but the fan fails to
run after approx. 3 mins.
D) Main burner operating intermittently
E) Main burner operating with
intermittent fan operation
F) Fan runs for excessive periods or
intermittently after main burner shuts
down
G) Noisy operation
MODAIRFLOWMODELS
H) Incorrect operation of fan and main
burner
NON-MODAIRFLOWMODELS
I) Pilot alight but main burner not igniting

1716
MAINBURNERNOTCYCLING
(ROOMTEMPERATURETOOHIGH)
REPLACE
MULTIFUNCTIONAL
CONTROL
N
YREPLACE
ELECTRONICS
MODULE
DISCONNECT
YELLOWWIREAT
MULTIFUNCTIONAL
CONTROL
N
DOES
BURNER
GO
OUT?
DISCONNECT
THERMISTA-STAT
REPLACE
THERMISTA-STAT
Y
DOES
BURNER
GO OUT?
N
CHECKFORVOLTAGEAT
FANLIVETOEARTH
REPLACE
ELECTRONICS
MODULE
Y
N
IS
FUSE
OK ? REPLACEFUSE
N
Y
CHECKFOR
VOLTAGE
ATFANLIVETO
NEUTRAL
MAIN BURNER ON, BUT FAN NOT RUNNING
YREPLACEFAN
DOES
FAN
START?
N
BRIDGEOUT
AIRFLOWSENSOR
YREPLACE
AIRFLOWSENSOR
REPLACE
TRANSFORMER
Remedy
Check for gas at inlet pressure test point
on the multifunctional control
Purge gas suply pip in accordance with BS
6891
Clear pilot orifice or replace pilot injector
Check igniter, lead and electrode.
Check that the mains gas pressure is 20
mbar and reduce if necessary.
Check that connection is secure.
Replace multifunctional control
Replace thermocouple
Check connections from electrical panel to
fan.
Check connections
Check for correct settings
Replace,taking carenotto damageimpeller
Replace
Check gas rate and burner pressure
setting.
Adjust fan speed or gas rate accordingly
Check that filter and air path is clear
Open additional outlets
Carry out spillage test and retify
ReplaceTTB
Check gas rate and burner pressure
settings
Check for correct settings
Check for correct settings
Check burner pressure settings
Replace fan assembly
Adjust fan speed
Consult diagnostics chart and follow
recommended procedure.
Check mains supply
Check that the time control and room
thermostat are operating correctly
Replace fuse and check for short circuits
Check connections
Check with test meter/replace if necessary
Replace
Short cicuit switch & replace if necessary
Fit temporary loop in heater thermostat socket.
Ifheaterignitescheckexternalcircuit.
Possible Cause
1) No gas to the heater
2) Gas supply not purged
3)Pilot orifice restricted
4) Piezo system faulty.
5) Excessive gas supply pressure
1) Connection between thermocouple and
mutifunctional control not secure
2) Faulty power unit multifunctional
control
3) Faulty thermocouple
1) No voltage to fan
2) Loose electrical connection on fan
delay control
3) Fan delay control set incorrectly
4) Faulty fan assembly
5) Faulty fan delay control
1) Gas rate or burner pressure setting
high
2) Temp rise excessive
3) Air filter or return air path restricted.
4) Excessive number of oulets closed
5) Spillage of flue gases.
6) Spillagemonitoringdevice(TTB) faulty.
1) Gas rate or burner pressure setting too
low
2) Fan delay control set incorretly
1) Fan delay control set incorrectly
1) Gas pressure too high
2) Noisy fan motor
3) Fan speed setting too high
1) Fault related to Modairflow Control
system.(See relevant pages)
1) Mains electrical suply not connected
to heater.
2) No demand for heat
3) 3A fuse failed
4) Loose connection to rom thermostat,
limitswitch, Multifunctional Control
lead,Time Control or transformer
5) Transformer open circuit
6) Multifunctional Control faulty
7) Limit switch Faulty
8) Room thermostat/external wiring faulty
or room thermostat faulty
Symptom
A) Pilot will not light
B) Pilot lights but goes out on releasing
START button during initial light-up,
or after normal operation.
C) Main burner lights but the fan fails to
run after approx. 3 mins.
D) Main burner operating intermittently
E) Main burner operating with
intermittent fan operation
F) Fan runs for excessive periods or
intermittently after main burner shuts
down
G) Noisy operation
MODAIRFLOWMODELS
H) Incorrect operation of fan and main
burner
NON-MODAIRFLOWMODELS
I) Pilot alight but main burner not igniting

1518
8.14 SPILLAGEMONITORDEVICE(TTB)REMOVAL:
8.14.1 Ensure that the electrical supply is isolated.
8.14.2 Remove the appliance lower and upper doors.
8.14.3 Remove theAir Circulation fan as detailed in para 8.8.
8.14.4 Cover the aperture to the heat exchanger in the top shelf to prevent objects falling into the heat exchanger.
8.14.5 Release and remove 6 x screws securing the fan compartment rear access panel, and withdraw the panel.
8.14.6 Disconnect the TTB terminal block plug from the terminal block socket, situated on the compartment rear bulkhead,
remove the grommet rearwards and pass the terminal block through the aperture in the rear bulkhead.
8.14.7 Release and remove the 5mm nut and lock washer securing the TTBAssembly to the Draught Diverter, and withdraw
the TTBAssembly.
8.14.8 Refitting or replacement is in reverse order.
8.15 HEATEXCHANGERACCESS:
8.15.1 Release 2 x securing screws and remove heat exchanger access caps and gaskets.
8.15.2 Remove the heat exchanger baffles.
8.15.3 Reassembly is in reverse order.
NOTE:When reassembling,ensurethatthebaffles arepushedfullyhomeand theaccess capsarefully sealed.In theeventof
heatexchangerreplacementbeingnecessary,contact Johnsonand Starley ServiceDepartment.
9. DEFECTDIAGNOSIS
9.1 IMPORTANT:
If an electrical defect occurs after installation of the appliance; preliminary earth continuity, polarity, and resistance to earth
checks should be carried out with a multimeter. On completion of any maintenance/fault-finding task that has required the
breaking and remaking of electrical connections, then checks of continuity, polarity, and resistance to earth must be
repeated.
9.2 WARNINGS:
9.2.1 When purging or checking gas supplies, ensure that ventilation to the room or cupboard is adequate, and that all
naked lights are extinguished.
9.2.2 MODAIRFLOWmodels: Before commencing defect diagnosis, ensure that the Thermista-stat is set to maximum,
mains supply is ‘ON’ and the time control is at an ‘ON’ position.
9.2.3 Care is to be taken during the replacement and handling of electronic assemblies, (i.e., electronic panel, airflow sensor
or Thermista-stat). It is not practical to rectify defects on these assemblies, except at the manufacturer, and any
attempt to do so may render the guarantee or factory replacement arrangement invalid.
MAIN BURNER NOT OPERATING
IS
PILOT
LIT?
IS 230V
SUPPLY
ON ?
IS TIME
CONTROL &
THERMISTA-STAT
CORRECTLY
SET ?
CHECK
TERMINAL
D9 IS
18V
CHECK
TERMINAL
C8 IS
230V
CHECK
TERMINAL
C10 IS
24V
REPLACE
ELECTRONIC
MODULE
IS
GAS
ON?
NTURNGAS
ON
N
LIGHT
PILOT
Y
Y
SWITCHON
230 V N
Y
N
Y
REPLACE
FUSE
N
Y
REPLACE
MULTIFUNCTIONAL
CONTROL
SETCONTROLS
CORRECTLY
Y
N
CHECKPOLARITYOF
THERMISTA-STAT
CONNECTIONS
Y
IS
POLARITY
CORRECT?
NRECTIFY
DEFECT
Y
BRIDGE THERMISTA-STAT
TERMINALS AT HEATER
BRIDGETHERMISTA-STAT
TERMINALSATHEATER
IS
BURNER
LIT?
IS
BURNER
LIT ?
WIRINGDEFECT
BETWEENHEATER
&
THERMISTA-STAT
N
Y
N
N
Y
N
CHECKTTB,
LIMITSWITCH
&
CONNECTIONS
Y
N
CHECK230VI/P
&TIMECONTROL
OPERATION
REPLACE
THERMISTA-STAT
REPLACE
TRANSFORMER
Y
IS
FUSE
OK ?
CHECK
24V AT
MULTIFUNC-
TIONAL
CONTROL

14 19
FANOPERATES,BUTBURNERCYCLESBEFOREREQUIREDTEMPERATUREISREACHED
BRIDGE
THERMISTA-STAT
N
CHECK AIR FILTER &
RETURN AIR PATH FOR
RESTRICTIONS
SET FAN SELECTOR TO
AUTO & BRIDGE AIRFLOW
SENSOR
N
CHECKTEMPERATURE
RISE ACROSS HEATER IS
LESS THAN 60°c
CHECKTTB,LIMITSWITCH
&CONNECTIONS
Y
Y
CHECK MAIN
BURNER
PRESSURE SETTINGS
ARE CORRECT
SETTOCORRECT
PRESSURESETTING
N
Y
SETFAN
BALANCINGSCREW
Y
DOES
FAN
SPEED
UP?
N
Y
REPLACE
ELECTRONICMODULE
REPLACE
ELECTRONICMODULE
REPLACE
AIRFLOWSENSOR
IS
PATH
CLEAR?
NCLEARRESTRICTIONS
ANDBLOCKAGES
CHECK FAN BALANC-
ING SCREW IS
CORRECTLY SET
N
DOES
FAN
SPEED
UP?
N
Y
SET FAN SELECTOR
SWITCH TO
CONTINUOUS
DOES
BURNER
STAY
LIT?
REPLACE
THERMISTA-STAT
Y
REPLACE
ELECTRONICMODULE
N
Y
IS
OVERHEAT
CONTROL
OK?
NON-MODAIRFLOW models:
8.9.6 Disconnectthe following:
a. Disconnect 230V connections (L/N/E) from the FanAssembly,
b. 230V mains ‘L’,‘N’and ‘E’from connection block terminals ‘1’and ‘3’, and earth stud respectively,
c. Room thermostat from connection block terminals ‘5’ and ‘6’,
d. Limit switch‘LOAD’ and‘COMMON’ connections,
e. FanControl ‘LOAD’,‘COMMON’and ‘EARTH’connections,
Both model types:
8.9.7 Disconnect 2 x TTB connections.
8.9.8 Disconnect the Multifunctional Control connections.
8.9.9 Disconnect the Water Circulator electrical connections (if fitted).
8.9.10 Release 4 x 4mm screws securing the Electrical assembly to the heater cabinet and remove the Electrical assembly,
releasing wiring from cable clamps and grommets as required..
8.9.11 Refitting or replacement is in reverse order.
8.10 ELECTRONICMODULEREMOVAL(MODAIRFLOWMODELSONLY)
8.10.1 Remove the ElectricalAssembly as detailed in sect 8.9.
8.10.2 Disconnect the Electronic Module from the ElectricalAssembly.
8.10.3 Release 3 x screws securing the Electronic Module to the Electrical Mssembly and remove the module.
8.10.4 Refitting or replacement is in reverse order.
8.11 TRANSFORMERREMOVAL(MODAIRFLOWMODELSONLY):
8.11.1 Remove the ElectricalAssembly as detailed in sect 8.9.
8.11.2 Disconnect the Transformer from the ElectricalAssembly terminal block, and the fuse from the Earth stud,
8.11.3 Release 2 x screws and nuts securing the Transformer to the ElectricalAssembly, and remove the Transformer.
8.11.4 Refitting or replacement is in reverse order.
8.12 TIMECONTROLREMOVAL:
8.12.1 Ensure that the electrical supply is isolated.
8.12.2 Release the securing screw situated on the lower face of the Time Control and remove it by partially withdrawing
bottom of the Time Control and then lifting upwards.
8.12.3 Disconnect the Time Control electrical connections from its integral terminal strip.
8.12.4 Refitting or replacement is in reverse order.
8.12.5 Set the Time Control to the required ON and OFF times.
8.12.6 Set the Time Control to the correct time.
8.13 FANDELAYCONTROL,LIMITSWITCHANDAIRFLOWSENSORREMOVAL:
NOTE:Airflow sensor applies to MODAIRFLOW models only, whilst Fan Delay Control applies solely to non-MODAIRFLOW
models.
8.13.1 Ensure that the electrical supply is isolated.
8.13.2 Remove the appliance lower and upper doors.
8.13.3 Release 2 x 4mm screws securing the Limit Switch cover and withdraw the cover.
8.13.4 Disconnect the required control/switch.
8.13.5 Release 2 x securing screws and remove the required control/switch.
8.13.6 Refitting or replacement is in reverse order.

1320
DEFECTISOPENCIRCUIT
INTHERMISTA-STAT
INSTALLATIONWIRING
DOES
BURNER
STAY
LIT?
YREPLACE
THERMISTA-STAT
BRIDGETERMINALSAT
THERMISTA-STAT
Y
IS
POLARITY
OK ?
NRECTIFY
CHECKTHERMISTA-STAT
CONNECTIONSPOLARITIES
Y
REPLACE
ELECTRONICMODULE
N
DOES
BURNER
STAY
LIT?
BRIDGETHERMISTA-STATAT
HEATER
Y
SETTHERMISTA-STAT
TOMAX
IS
THERMISTA-
STAT
SET TO
MAX ?
N
N
MAIN BURNER ONLYFIRES FOR SHORT PERIODS 8.5 PILOTBURNER,THERMOCOUPLEANDELECTRODE,REMOVALANDREPLACEMENT:
8.5.1 Remove the Burner and ControlAssembly as detailed in 8.2
8.5.2 Disconnect the Igniter lead from the Piezo unit.
8.5.3 Disconnect the Thermocouple from the Thermocouple adapter on the Multifunctional Control, taking care to avoid
damage to the thermocouple capillary.
8.5.4 Release the Pilot Feed Pipe from the Multifunctional Control.
8.5.5 Remove 2 x 4mm screws securing the Pilot Burner assembly to the Burner and Control assembly, and withdraw the Pilot
BurnerAssembly.
8.5.6 Release the Thermocouple securing nut from the Pilot Burner assembly and withdraw the Thermocouple, taking care to
avoid damaging the Thermocouple capillary.
8.5.7 Release the Electrode securing nut from the Pilot Burner assembly and withdraw the Electrode.
8.5.8 Release the Pilot Feed Pipe securing nut from the Pilot burner assembly and withdraw the Pilot Feed Pipe and Pilot
Injector from the Pilot Burner assembly, and disconnect the Pilot Injector from the Pilot Feed Pipe hook.
8.5.9 Refitting or replacement is in reverse order.
NOTE:WhenrefittingorreplacingThermocouple,tightenonlytoFINGERTIGHT+1FLAT.
8.6 MULTIFUNCTIONALCONTROLREMOVAL:
8.6.1 Remove the Burner and ControlAssembly as detailed in 8.2
8.6.2 Disconnect the Thermocouple at the Multifunctional Control (including the adapter), avoiding damage to the capillary.
8.6.3 Disconnect the Pilot Feed Pipe from the Multifunctional Control.
8.6.4 Disconnect the Multifunctional Control input and output supply feeds.
8.6.5 Refitting or replacement is in reverse order.
8.7 PIEZOUNITREMOVAL:
8.7.1 Disconnect 2 x conductors from Piezo unit.
8.7.2 Unscrew the Piezo retaining nut and remove the unit from its mounting bracket.
8.7.3 Refitting or replacement is in reverse order.
8.8 AIRCIRCULATINGFAN,REMOVALANDCLEANING:
8.8.1 Ensure that the electrical supply is isolated.
8.8.2 Remove the appliance lower and upper doors.
8.8.3 Disconnect the 230V connections (L/N/E) from the FanAssembly.
8.8.4 Release 4 x screws securing the control panel, and withdraw the panel, avoiding damage to wiring.
8.8.5 Release 2 x FanAssembly securing screws and withdraw the FanAssembly from the Heater cabinet, avoiding damage
to fan blades.
8.8.6 Remove all dust from the impeller and motor, avoiding damage to the fan blades.
8.8.7 Refitting or replacement is in reverse order.
8.9 ELECTRICALASSEMBLYREMOVAL:
8.9.1 Ensure that the electrical supply is isolated.
8.9.2 Remove the appliance lower and upper doors.
8.9.3 Release 2 x 4mm screws securing the Limit switch cover and the withdraw cover.
8.9.4 Release the ElectricalAssembly cable clamp,
MODAIRFLOWmodels:
8.9.5 Disconnect the following:
a. Disconnect 230Vconnections (L/N/E) from FanAssembly,
b. 230V mains ‘L’,‘N’and ‘E’from connection blockterminals ‘1’, ‘3’and‘2’respectively,
c. Thermista-stat connections from connection block terminals ‘4’ (+ve) and ‘5’ (-ve),
d. Limit Switch‘LOAD’and ‘COMMON’connections,
e. 2 xAirflow sensor connections,