Powrmatic NV Series User guide

Users, Installation and Servicing
Instructions
WARNING: THIS APPLIANC MUST B ARTH D
CE
£4.00 When supplied separately. NV Range Users, Installation & Servi ing Instru tions Issue 3.8 O tober 2009
The NV Range
Pactrol Control

Dear Customer
This is to certify that this appliance is guaranteed for two years including parts and
labour from the date of original commissioning.
The heat exchanger, where fitted, is guaranteed (parts only) for a further eight years,
chargeable on a sliding scale basis, price relative to age.
To make a claim
In the first instance you must contact your appliance supplier, or installer and
provide:
1. The appliance type and serial number.
2. The original commissioning documentation.
3. As much detail as possible on the fault.
Your supplier, or installer will then contact Powrmatic to make a guarantee claim
on your behalf.
Conditions of Guarantee
1. The appliance must have been installed by a competent recognised installer,
and in accordance with the manufacturers instructions, building regulations and
local regulations.
2. The appliance has been professionally commissioned.
3. The appliance has been maintained on a yearly basis by a competent servicing
company.
4. The appliance has been used in accordance with the manufacturers instructions.
5. The correct specification fuel has been used
6. No unauthorised repairs or modifications have been made.
7. Powrmatic General Conditions of Sale have been observed.
8. Except for the obligation of Powrmatic Ltd to perform warranty repairs during
the guarantee period, Powrmatic will not be liable in respect of any claim for
direct or indirect consequential losses, including loss of profits or increased costs
arising from loss of use of the appliance, or any event arising there from.
Exclusions
1. Gaskets and fan belts are not included in the guarantee
Important: This certificate must
be kept with the appliance
Certificate of Guarantee
Powrmatic Ltd, Hort Bridge, Ilminster, Somerset, TA19 9PS
tel: [phone] fax: [phone]
web: www.powrmatic.co.uk

1. Checks before lighting the Air
Heater
The following preliminary checks should be made before lighting
the heater(s)
a) Ensure that the ELECT ICAL supply to the heater is
switched OFF.
b) Check that all warm air delivery outlets are open.
c) Check that the thermostat is set at MAX.
d) Check that the clock control is set to an ON period.
e) Check that any other controls are calling for heat.
f) Ensure that the Summer/Winter switch is in the Winter
position.
g) Check that the overheat reset button has not operated.
2. Lighting the Air Heater
NOTE:
On initial lighting of the heater(s), it may take some time to
purge the internal pipework of air. If it is not possible to light
the heater after several attempts contact the local service
company.
1. Switch on the electrical supply at the isolator and the start
up sequence will commence. The internal exhaust fan will run.
When sufficient combustion airflow is proved by the air pressure
switch the ignition spark will be generated and the main gas
valves energized. The burners will then light.
2. If the burners fail to light the control box will go to lockout
and the lockout light on the low level remote reset will be
illuminated. To restart the ignition sequence depress the reset
button on the low level reset for about 5 seconds.
If the unit will not light after four or five attempts then shut
down the unit and call in a service engineer.
3. To Shut Down the Air Heater
3.1 For Short Periods: Turn the room thermostat to the OFF
or lowest setting.
3.2 For Long Periods: Complete step 3.1 above. Wait for 5
minutes and then turn OFF the
electrical supply at the isolator.
4. Description of Operation
Important: All heaters must be controlled by the fitted external
controls and not by use of the main switch in the electrical
supply to the heater.
4.1 Standard Units
The ignition sequence will commence each time that the external
controls e.g. Timeclock, room thermostat etc. call for heat. The
heater fan will automatically start between 0 - 30seconds
(depending on the setting of the internal timer) after the main
burners light. When the external controls are satisfied the main
burners will be turned off and approximately 2 - 3 minutes later
the heater fan will be automatically stopped.
4.2 High / Lo & Modulating Units
When the main burners are alight the heat output will be
controlled either to high fire or low fire or, in the case of
modulating units, to any point between high and low fire;
depending on the requirements of the space being heated and
the external controls fitted.
4.3 Summer / Winter Modes
Certain types of external controls will provide for two modes
of operation i.e.
Summer: The heater fan alone will run at the dictate of the
external controls to provide air movement.
Winter: The heater will operate normally.
5. Maintenance
egular servicing is essential to maintain efficient, reliable and
safe operation of the heater. Users are strongly recommended
to have the heater serviced by a qualified person at least annually
and preferably at the end of the heating season.
6. IMPORTANT
Free access must be maintained to and around the heater for
servicing purposes and the air supply to the heater must not be
restricted in any way. Combustible materials must not be stored
adjacent to the heater.
If at any time a gas leak is suspected turn OFF the gas supply
- DO NOT USE A NAKED FLAME - and contact the local gas
undertaking immediately.
All Powrmatic heaters use gas and electricity to power them,
they may also contain moving parts such as pulley belts. It
would be hazardous to tamper with or attempt to service unless
you are a competent person in the field of Gas and Electrical
work.
If you have any safety questions reference the servicing and
installation of any of our heaters please do not hesitate to contact
our head office for expert advice.
Your safety is paramount to us.
Gas Safety (Installation & Use) (Amendment) Reg lations
It is law that all gas appliances are installed, adjusted and, if
necessary, converted by qualified persons* in accordance with
the current issue of the above regulations. Failure to install
appliances correctly can lead to prosecution. It is in your own
interests and that of safety to ensure that the law is complied
with.
* An approved class of person listed on the gas register.
Users Instructions

CONTENTS
Section Title Page
1. Introd ction 1
2. Technical Data 2
3. General Req irements 5
4. Installation 6
5. Air Distrib tion System 9
6. Commissioning & Testing 9
7. Servicing 11
8. Connections to External Controls 13
9. Fa lt Finding Flow Chart 15
10. Short List of Parts 16
Tables Title Page
1. Dimensions 3
2. Specifications 3
3.1 Injector Sizes & B rner Press res
Nat ral Gas - Gro p H - G20 4
3.2 Injector Sizes & B rner Press res
Propane - G31 4
4. Electrical Loadings 1ph 4
Figure Title Page
1a. Exha st only system - horizontal 7
1b. Exha st only system - vertical 7
2a. Individ al system - horizontal 8
2b. Individ al system - vertical 8
3. Controls Layo t 9
4. Governor adj stment (Honeywell VR425A) 10
5. Governor adj stment (Honeywell VR4605A) 10
6. High/Lo Reg lator 10
6. Mod lating Reg lator 11
8. Ignition Electrode Spark Gap 11
Installation & Servicing Instructions

1. INTRODUCTION
The NV range are highly efficient gas fired, fanned circulation
air heaters that cover heat outputs of 10kW to 140kW, have a
closed combustion circuit and are supplied complete with a flue
system. They are certified for use on Natural Gas, Group H -
G20, and Propane - G31 only.
Appliance Categories are Cat II2H3P (GB, IE).
The heaters are designed to be suspended from suitable roof
points or alternatively to be mounted on purpose designed
brackets and are intended primarily for heating commercial or
industrial premises. They may be used where the atmosphere
inside the premises could be contaminated e.g. Dust, oil mist
etc. but the heaters are not airtight and therefore may not be
used in areas classified as hazardous as defined in
BS 5345: Part 2 or areas subjected to significant negative
pressures due to extract systems.
NV/F heaters have an axial fan assembly fitted at the rear to
circulate the air being heated through the folded tube heat
exchanger. NV/C units are supplied with a centrifugal fan/silencer
duct section and NV/D units for use with ducted systems where
the air moving fan is by others or a centrifugal fan section is
used remote from the heater. NV/DH units are for use in air
handling units and NV/EA units are for siting externally.
Heaters are fitted as standard with atmospheric inshot burners,
a fully automatic control for ignition, flame sensing, gas supply
control and safety functions, an internal exhaust fan, main air
fan (/F and /C models), fan timer, high temperature thermostat
and limit thermostat.
Options include HIGH/LOW or modulating burner controls,
inlet duct connection, outlet duct connection, 45° head, 90°
outlet bend, vertical/horizontal outlet louvre assembly and a
full range of modular duct components.
Gas Safety (Installation & Use) Reg lations
It is law that all gas appliances are installed, adjusted and, if
necessary, converted by qualified persons* in accordance with
the current issue of the above regulations. Failure to install
appliances correctly can lead to prosecution. It is in your own
interests and that of safety to ensure that the law is complied
with.
* An approved class of person listed on the gas register.
1

B
A
Front
455
120
C
DE
F
G
C
NV140/F SHOWN
Top
NV60/D SHOWN
700
F
H
Side
J
B
A
Front
455
120
C
DE
F
G
Top
NV20/D WITH CENTRIFUGAL FAN/SILENCER SECTION SHOWN
700
F
H
J
Side
700
F
H
Side
455
120
C
DE
F
G
Top
M
B
Front
A
2. T CHNICAL DATA
2
10mm Suspension Points Alternative
flue positions
K
L
65
Alternative
flue positions
Alternative
flue positions
Alternative
flue positions

Table 2 - Specifications
Table 1. Dimensions
3
Note: /D data refers to Powrmatic supplied centrifugal/silencer duct section
NV15
NV25
NV30
NV50
NV60
NV75
NV90
NV120
NV140
NV35
Model ABCD FGHJ M
NV10
590
818
1035
1000
1345
2345
506
740
870
176
258
172.5
202
142
220
236.5
248.5
244.5
123.5
818
970
970
705
870
750 296 192
181
Flue
Ø (mm)
80
100
130
120 262.5
118
109
750
K
1010
2014
697
502
436
L
524
631
752
904
752
904
639
804
969
1948
944
NV20
NV40
NOPQ
116
146
88
189
151
227
151
153
401
83
510
738
890
738
890
624
789
954
MOD L
INPUT
(Nett) OUTPUT INPUT
(Nett) OUTPUT
kg
kW kW m³/s Pa kW
NV10 10.79 10.0 6.57 5.90 0.2601
NV15 16.00 15.0 8.22 7.50 0.3902
NV20 21.85 20.0 11.58 9.92 0.5203
NV25 27.32 25.0 16.50 14.30 0.6503
NV30 32.60 30.0 18.34 16.30 0.7804
NV40 43.48 40.0 24.19 21.22 1.0405
NV50 54.23 50.0 28.40 24.83 1.3006
N/A 0.040 53
140 0.250 91.5
N/A 0.120 54
145 0.370 106.5
N/A 0.070 68
177 0.370 120.5
N/A 0.180 89
143 0.370 126.5
N/A 0.180 89
250 1.100 166.5
N/A 0.300 93
236 1.100 168.5
N/A 0.440 114
205 1.100 183
F
D
F
D
F
D
F
D
F
D
F
D
F
D
HIGH FIR LOW FIR
AIR
VOLUM
MAXIMUM
DUCT
R SISTANC
FAN
MOTOR W IGHT
NV60 65.22 60.0 35.63 31.49 1.5608
N/A 0.550 130
250 1.50 213
D
F
F
D
F
D
D
F
NV75
NV90
NV120
81.25 75.0
95.25 90.0
126.32 120.0
42.61 37.50
58.50 54.50
75.45 71.00
1.9510
2.3412
3.1215
N/A 0.550 150
260 1.50 234
N/A 2 x 0.440 188
200 2 x 1.10 343
N/A 2 x 0.550 260
284 2 x 1.50 363.5
D
F
NV140 148.93 140.0 98.92 92.55 3.6418
N/A 2 x 0.550 260
285 2 x 1.50 424
NOIS
L V L
dB(A) @ 3m
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
46
54
52
53
54
58
61
62
62
66
67
67
NV35
F
D
39.32 35.0 23.1 19.0 1.000
N/A 0.300 89
210 1.100 166.5
N/A
58

Minimum
Inlet pressure
17.5mbar
Inlet INJ CTORS
High Fire Low Fire
Pressure Burner Gas Rate Burner Gas Rate
20mb Pressure Pressure
MOD L No. Size Marked mbar m³/h mbar m³/h
mm
NV10 4 1.36 240 13.2 1.14 5.3 0.70
NV15 4 1.67 380 12.5 1.69 3.5 0.87
NV20 4 1.94 500 12.7 2.31 4.0 1.23
NV25 5 1.94 500 12.5 2.89 4.7 1.75
NV30 6 1.94 500 11.9 3.45 4.0 1.94
NV35 6 2.26 580 9.5 4.16 4.1 2.44
NV40 8 1.94 500 13.5 4.60 4.0 2.56
NV50 10 1.94 500 13.2 5.74 4.0 3.01
NV60 8 2.54 750 9.5 6.90 2.7 3.77
NV75 10 2.54 750 9.5 8.60 2.9 4.51
NV90 6 3.5 1500 9.1 10.08 3.5 6.19
NV120 8 3.5 1500 9.1 13.37 3.4 7.98
NV140 10 3.5 1500 8.4 15.76 4.0 10.47
Inlet Pressure
37mbar
Table 4
lectrical Loadings 1ph
4
Table 3.1
Injector Sizes & Burner Pressures Natural Gas - Group H - G20 Net CV (Hi) = 34.02MJ/m³
Table 3.2
Injector Sizes & Burner Pressures - Propane G31 - Net CV (Hi) = 88.00MJ/m³
Inlet INJ CTORS
High Fire Low Fire
Pressure Burner Gas Rate Burner Gas Rate
37mb Pressure Pressure
MOD L No. Size Marked mbar m³/h mbar m³/h
mm
NV10 4 0.90 90 28.0 0.44 10.0 0.27
NV15 4 1.10 110 28.5 0.65 10.0 0.34
NV20 4 1.25 125 31.0 0.89 9.9 0.47
NV25 5 1.25 125 30.6 1.12 11.5 0.67
NV30 6 1.25 125 27.0 1.33 10.0 0.75
NV35 6 1.36 136 20.5 1.61 9.2 0.95
NV40 8 1.25 125 28.5 1.78 10.0 0.99
NV50 10 1.25 125 29.2 2.22 9.7 1.16
NV60 8 1.55 155 27.0 2.67 10.0 1.46
NV75 10 1.55 155 27.0 3.32 10.0 1.74
NV90 6 2.10 210 26.3 3.90 9.8 2.39
NV120 8 2.10 210 27.0 5.17 10.0 3.09
NV140 10 2.10 210 26.1 6.09 9.5 4.04
NV 90
NV 120
7.81 4.22
9.57 5.13
NV 140 9.64 4.98
/F Models Centrifugal Fan Sections
MOD L
PLAT
AMPS
(A)
START
AMPS
(A)
RUN
AMPS
(A)
FUS
RATING
(A)
NV 10
2
NV 15
0.18 0.34 0.16
870
2.8 4.2 2.10
1.39 0.51 4.0 8.1 2.60
NV 20 0.38 0.28 4.0 7.8 3.20
3
NV 30 1.83 0.61 14.7 4.50
7
NV 40 1.30 2.56 1.35 8.4 14.5 5.00
NV 50 1.40 4.01 1.96 3 16.0 6.40
NV 60 4.70 2.44
NV 75 4.78 2.51
2 x 1.40
NOMINAL
MOTOR
R.P.M.
PLAT
AMPS
(A)
START
AMPS
(A)
RUN
AMPS
(A)
FUS
RATING
(A)
NV 25 1.89 0.62
0.54
0.89
2.50
2 x 2.50
0.31
7
5
NOMINAL
MOTOR
R.P.M.
4.0 8.2 2.90
28.4 11.6
25
900
1400
775
910
820
900
11.1
2 x 8.4
2 x 11.1
24.5 10.6
42.5 21.5
24.5 12.3 16
NV 35
Note: 3ph Data is
supplied seperately with
units ordered to this
specification.
14.0
39.8
5.30
25.2
5

3. General Requirements
3.1 Related Documents
The installation of the air heater(s) must be in accordance with
the rules in force and the relevant requirements of the Gas Safety
egulations, Building egulations and the I.E.E. egulations
for Electrical Installations.
It should also be in accordance with any relevant requirements
of the local gas region, local authority and fire authority and
the relevant recommendations of the following documents.
Institution of Gas Engineers & Managers
IGE/UP/1 (Ed.2) Strength and tightness testing and purging of
industrial and commercial gas installations.
IGE/UP/1A Soundness testing and direct purging of small low
pressure industrial and commercial gas installations.
IGE/UP/2 Gas installation pipework, boosters and compressors
on industrial and commercial premises.
IGE/UP/10 Installation gas appliances in industrial and
commercial premises.
British Standards Code of Practice
BS 5588 Fire precautions in the design and construction of
buildings.
Part 2 : 1985 Code of Practice for Shops
Part 3 : 1983 Code of Practice for Office Buildings
BS 6230: 1991 Installation of Gas Fired Forced Convection Air
Heaters for Commercial and Industrial Space Heating.
Those appliances having a gross input rating not exceeding
60kW viz. NV10 to NV50 inclusive and installed so as to take
their combustion air from within the building must be installed
in accordance with the relevant recommendations of the following
document.
BS 5440 Flues and Air Supply for gas appliances of rated input
not exceeding 60kW (1st and 2nd family gases), Part 2 - Air
Supply
For NV/D units of 10 - 50 size, reference should also be made
to
BS 5864. Code of Practice for installation of gas-fired ducted-
air heaters of rated input not exceeding 60kW.
3.2 Location
The location chosen for the air heater must permit:
- provision of a satisfactory flue system and adequate air supply.
- adequate space for servicing and air circulation around the air
heater.
IMPO TANT:
1. Heaters shall not be installed in:-
a) Those parts of spaces within buildings that have been classified
as hazardous areas as defined in BS 5345 : Part 2.
b) Where there is a foreseeable risk of flammable particles or
gases or corrosion inducing gases or vapours being drawn into
either the heated air stream or the air for combustion. In such
cases installation may only proceed if the air to be heated is
ducted to the heater from an uncontaminated source, preferably
from outside the building. The option of taking combustion air
from the space is not permitted. Where only airborne particles
are present it may suffice to fit filters on the main air inlet duct
of the heater and advice may be obtained from Powrmatic Ltd.
c) Particular care should be taken to ensure chlorine vapours
(from Freon, degreaser compounds etc.) are not induced into
the combustion air stream as severe heat exchanger damage
will result.
d) In areas subjected to significant negative pressures due to
extract systems.
Where the location of the air heater is such that it might suffer
external mechanical damage e.g. from overhead cranes, fork
lift trucks, it must be suitably protected.
NV units are designed to operate within an ambient temperature
range of -10 to 25°C.
3.3 Gas Supply
3.3.1 Service Pipes
The local gas undertaking should be consulted at the installation
planning stage in order to establish the availability of an adequate
supply of gas. An existing service pipe must not be used without
prior consultation with the local gas undertaking.The inlet gas
pressure under running conditions must not be less than 17.5mb.
3.3.2 Meters
An existing meter should be checked, preferably by the gas
undertaking, to ensure that the meter is adequate to deal with
the total rate of gas supply required by all connected equipment.
3.3.3. Installation Pipes
Installation pipes should be fitted in accordance with
IGE/UP/2. Pipework from the meter to the air heater must be
of adequate size. Do not use pipes of a smaller size than the
inlet gas connection of the heater. The complete installation
must be tested for soundness as described in the above Code.
3.3.4. Boosted Supplies
Where it is necessary to employ a gas pressure booster the
controls must include a low pressure cut off switch at the booster
inlet. The local gas undertaking must be consulted before a gas
pressure booster is fitted.
3.4 Flue System
NV units feature a closed combustion circuit and have an internal
exhaust fan, mounted downstream of the heat exchanger, to
evacuate the products of combustion and draw in air for
combustion.
The air heater must be connected to the flue system that is
provided by Powrmatic Ltd. Several configurations of flue and
combustion air ducts are available (See Page & 8 Figs 1a to
2b).
The flue must terminate in a freely exposed position and be
sited to prevent the products of combustion entering any opening
in a building in such concentration as to be prejudicial to health
or a nuisance.
3.5 Combustion Air Supply
Air inlet grilles shall be provided at low level when combustion
air is taken from within the space being heated and the building
has a design air change rate less than 0.5/h, and NV units are
installed in heated spaces having a volume less than 4.7 m³/kW
of total rated heat input:-
(1) for heaters of heat input less than 60 kW, the total
minimum free area shall not be less than 4.5 cm² per
kilowatt of rated heat input.
(2) for heaters of heat input 60 kW or more, the total
minimum free area shall not be less than 270cm² plus
2.25 cm² per kilowatt in excess of 60 kW rated heat input.
Where the air heater(s) are to be installed in a plant room the
plant room must have permanent air vents communicating
directly with the outside air, at high level and at low level.
Where communication with the outside air is possible only by
means of high level air vents, ducting down to floor level for
the lower vents should be used.
All air vents should have negligible resistance and must not be
sited in any position where they are likely to be easily blocked
5

6
4. Installation of Air Heater(s)
4.1 General
Before installation, check that the local distribution conditions,
nature of gas and pressure, and adjustment of the appliance are
compatible.
The air heater must be installed in accordance with the rules in
force and the relevant requirements of any fire regulations or
insurance company's requirements appertaining to the area in
which the heater is located, particularly where special risks are
involved such as areas where petrol vehicles are housed, where
cellulose spraying is carried out, in wood working departments
etc.
NV/C units are supplied with the centrifugal fan/silencer section
seperate from the heater which must be fitted at the rear of the
NV heater i.e the fan is blowing across the heat exchanger.
The following minimum clearances must be observed for
installation and servicing .
HS Clearance (looking at front of heater) 1.0m
LHS Clearance (looking at front of heater) 0.2m
Top of the heater to ceiling 0.2m
ear of heater to nearest wall 0.6m
(Depending on flue system used)
For multi air heater installations the following minimum distances
between units must be observed.
Between units, side to side 3.0m
Between units, back to back 3.0m
ecommended mounting heights, floor level to the underside
of the unit, are:-
NV10F - 30F 2.5m - 3m
NV40F - 150F 3m - 5m
NV/D Models Mounting heights not applicable
All models must not be installed at a height of less than 2.5m
to the base of the unit.
Any combustible material adjacent to the air heater and the flue
system must be so placed or shielded as to ensure that its
temperature does not exceed 65 °C.
When NV modular components are used in conjunction with
the heater each component must be individually supported.
4.2 Fitting the Air Heater
The air heater may be installed either:
a) suspended from suitable vertical drop rods,
chains or straps.
b) on specifically designed cantilever brackets from a
non-combustible wall.
c) on a level non-combustible surface. The surface must
not extend past the front edge of NV/F heaters.
The method of installation must be capable of adequately
supporting the weight of the unit (See Table 2, Page 3) and any
ancillary equipment. Before installing the heater the existing
structure must be inspected to ensure it is suitable. All supports
should be protected against the effects of rust or corrosion.
Threaded drop rods must have lock nuts fitted that are tightened
down onto the 10mm fixings in the heater.
If reducing noise levels is important the heater should be
insulated from the structure by installing it on suitable anti-
vibration mountings. In all such cases and when the heater is
suspended it is essential that all gas, duct, and electrical
connections to the heater are made with flexible connections
to maintain continuity of connection.
4.3 Flue/Combustion Air Duct System
All models are supplied as standard with a top flue outlet and
the flue outlet and combustion air sockets are loose inside the
controls section.
or flooded or in any position adjacent to an extraction system
which is carrying flammable vapour.
Grilles or louvres should be so designed that high velocity air
streams do not occur within the plant room.
The basic minimum effective area requirements of the air vents
are as follows:
(a) Low Level (inlet)
(1) for heaters of total rated heat input less than 60kW:
9cm² per kilowatt of rated heat input.
(2) for heaters of total rated heat input 60kW or more:
540 cm² plus 4.5 cm² per kilowatt in excess of 60
kW total rated input.
(b) High Level (outlet)
(1) for heaters of total rated heat input less than 60kW:
4.5cm² per kilowatt of rated heat input.
(2) for heaters of total rated heat input 60kW or more:
270 cm² plus 2.25 cm² per kilowattin excess of 60kW
total rated input.
3.6 Air Distribution System
Where single NV/F units are required to cover a large floor
area, and in buildings with high roof or ceiling heights Calecon
thermal economiser units should be fitted to ensure even heat
distribution and minimise stratification.
Care should be taken to avoid impeding the air throw with
racking, partitions, plant or machinery etc. Various outlet
configurations are available as optional extras to modify the air
throw pattern to suit particular site conditions.
For ducted units all delivery and return air ducts, including air
filters, jointing and any insulation or lining must be constructed
entirely of materials which will not contribute to a fire, are of
adequate strength and dimensionally stable for the maximum
internal and external temperatures to which they are to be
exposed during commissioning and normal operation.
Where inter-joist spaces are used as duct routes they should be
suitably lined with a fire-resisting material.
A full and unobstructed return air path to the air heater(s) must
be provided.
If the air heater(s) is installed in a plant room the return air
intake(s) and the warm air outlet(s) from the heater(s) must be
fully ducted, into and out of the plant room to avoid interference
with the operation of the heater.
The openings in the structure of the plant room through which
the ducting passes must be fire stopped.
Care must be taken to ensure that return-air intakes are kept
clear of sources of smells and fumes, and where there is any
possibility of pollution of the air by dust, shavings etc.,
precautions must be taken to prevent contamination.
If necessary suitable barrier rails should be provided to prevent
any combustible material being placed within 900mm of the
outlets.
3.7 lectrical Supply
Wiring external to the air heater must be installed in accordance
with the I.E.E. egulations for Electrical Installations and any
local regulations which apply.
All standard heaters are supplied by 230V - 1ph, 50Hz. The
method of connection to the main electricity supply must:-
- facilitate the complete electrical isolation of the unit(s)
- be in a readily accessible position adjacent to the unit(s)
- serve only the unit(s)
- have a contact separation of at least 3mm in all poles. See the
accompanying wiring diagram for the heater electrical
connections
NV centrifugal fan/silencer units can also be supplied for 400V
3N, 50Hz.

7
4.3.1.1. Conversion to Rear Flue Outlet
1. emove the two blanking plates from the flue /combustion
air openings at the rear of the unit.
2. emove the four screws from the exhaust fan oulet flange.
3. emove the two screws at the left hand side of the fan
mounting plate that secure it to the exhaust header.
4. emove fan assembly by pulling forwards and to the left to
disengage the retaining lugs.
5. otate the fan assembly 90° clockwise. emove the fixing
plate from the top of the fan box and reposition on the left hand
side. The screws from the left hand side are refitted at the top
to close off the open holes. Ensure that the gasket around the
inlet to the fan is not damaged, if necessary replace or make
good with silicon sealant.
6. Engage the locating lugs on the right hand side of the fan
box into the slots on the collector box, push fan against collector
box and secure with the two screws at the left hand side.
4.3.1.2 Fitting Flue/Combustion Air Sockets
1. Apply a bead of silicon sealant around the face of the flange
on the exhaust fan outlet tube that can be seen from the outside
of the heater. Place the flue socket on the outside of the heater
to mate with this flange and clamp the two flanges together, on
either side of the heater panel using the screws provided. Ensure
that the silicon sealant has sealed between the two flanges.
2. Apply a bead of silicon sealant around the face of the flange
of the combustion air socket, on the same side as the socket.
Passing the socket through the panel from the inside, position
the flange up against the panel. Secure, from the outside, with
the screws provided.
3. If ducted combustion air is not required (see Section 3.5) fit
the mesh inlet plate behind the unused combustion air inlet
hole.
4. Apply silicon sealant and refit blanking plates as required to
seal unused panel holes.
4.3.2. General Requirements
See Figures 1a to 2b for the different types of flue installation.
In all cases the flue outlet socket must be connected via the
provided flue system to outside air. The maximum permitted
length of flue system is 6m, or 12m if the flue outlet only is
used. If an offset is required two sets of 45° bends may be used
each set being equivalent to 0.5m of flue length. The minimum
flue length (end of flue terminal to back or top of heater) shall
not be less than 1.0m for the NV10 - 50 and 1.3m for the NV60
- 140.
All outer joints must be finished with the provided locking
bands. A smear of silicon grease to the inside of sockets will
assist in fitting components together. All flue and combustion
air ducts must be supported independently of the air heater. The
flue or flue/combustion air terminal must not be installed so as
to be less than:
- 300mm below an opening e.g. window, air brick etc.
- 200mm below eaves or gutter.
- 300mm from an internal or external corner.
- 1200mm from a surface facing the terminal.
- 1500mm vertically from another terminal on the same wall.
- 300mm horizontally from another terminal on the same wall.
- 2000mm from ground level.
4.3.3 Installation of Flue System
Note:A terminal guard, as supplied by Powrmatic Ltd, must be
fitted to horizontal flue terminals.
4.3.3.1 Horizontal System - Rear Outlet
Note: If the outlet is required to the side of the unit 90° bends
may be fitted directly onto the inlet/outlet spigots on the heater.
1. Locate the position of the flue terminal, allowing for a slight
gradient running down from the heater to the terminal of 2° -
3° and cut a hole to suit.
2. Fit the flue terminal, securing via the wall plate and weather
with silicon sealant or similar.
3. Fit the twin to concentric adaptor to the terminal section and
extend the flue and combustion air ducts to the heater using
straight lengths. Fit an adjustable length prior to the unit, to
facilitate flue disconnection for servicing. Extend the adjustable
lengths to make the final connection to the appropriate heater
inlet/outlet spigots.
4. Ensure that internal silicon sealing rings are in place and that
all tubes are pushed fully home. Secure concentric lengths with
the locking bands provided.
4.3.3.2 Vertical System - Top Outlet
1. Locate the position of the flue terminal cut a hole in the roof
to suit.
2. Fit the flashing and the flue terminal so that the lower edge
of the outer case is over the top of the flashing. Weather with
silicon sealant or similar.
Fit a condensate drain lenth into the flue socket on the heater
and an equivalent straight length onto the combustion air socket.
3. Fit the twin to concentric adaptor to the terminal section and
then extend down to the heater using straight lengths. Fit
Fig 1b Exha st only system - vertical
12m maximum
Terminal
Lengths
Adjustable
length
Flashing
Flue
so ket
Combustion air entry
(fitted with inlet grille)
Condensate drain
length
Fig 1a Exha st only system - horizontal
Terminal
Lengths
Adjustable
length
Flue
outlet
Combustion air entry
(fitted with inlet grille and
inlet bend (not shown))
12m maximum
Combustion air entry
(fitted with inlet grille)
Combustion air entry
(fitted with inlet grille and
inlet bend (not shown))

8
adjustable lengths as the final connection pieces, to facilitate
flue disconnection for servicing. Extend the adjustable lengths
to make the final connection but do not exceed the maximum
extended length so as to maintain joint integrity.
Extend the drainage offtake of the condensate drainage length
to a suitable gully or drain.
4. Ensure that internal silicon sealing rings are in place and that
all tubes are pushed fully home. Secure concentric lengths with
the locking bands provided.
4.3.3.3 Internal Combustion Air Systems
1. Complete the run of flue sections from the terminal spigot
to the flue outlet socket of the heater generally as described in
4.3.3.1 and 4.3.3.2, ensuring that the internal silicon sealing
rings are in place.
2. It is recommended that both air inlets are utilised and that
both are fitted with the mesh inlet plates supplied. In addition
a 90° bend should be fitted to the rear inlet, the inlet opening
of the bend facing to the side of the heater i.e. away from the
main air fan.
4.4 Gas Connection
Solid pipework must be fitted to the internal gas control and
exit through the heater casing and then be fitted with a servicing
valve and union to facilitate servicing. The gas supply to the
air heater must be completed in solid pipe work and be adequately
supported. Heaters suspended by drop rods, straps or chains
must have a flexible connection as the final link between the
gas supply pipe work and the heater. Sufficient slack must be
left in the connection to take account of normal movement of
the heater.
Warning
When completing the final gas connection to the heater do not
place undue strain on the gas pipe work of the heater.
4.5 lectrical Connections
All units, with the exception of NV/D units supplied with a
centrifugal fan/silencer duct section, are fully prewired and only
require final connections for the incoming mains supply and
completion of the control circuit (230V) via a room thermostat,
time clock etc. and the remote low level lockout reset.
Warning: Lockout reset is by a switched Neutral to the controls
in the heater.
All units must be earthed. The electrical supply must be run to
a point adjacent to the heater and be suitably terminated to
provide an isolation point that will prevent remote activation
of the unit during servicing. See Table 4 (Page 4) to ascertain
the electrical loading of the unit(s) so that cables of adequate
cross-sectional area are used for the electrical installation. The
length of the conductors between the cord anchorage and the
terminals must be such that the current carrying conductors
become taut before the earth conductor if the cable or cord slips
out of the cord anchorage. All external controls must be of an
approved type.
See the wiring diagram accompanying these instructions.
NV/D models supplied with a centrifugal fan/silencer duct
section require wiring to be completed between the heater and
fan. efer to supplied wiring diagram.
NV/D models supplied less fan must be electrically interlocked
to the air movement system so that this is started in the same
manner as the air heater fan would be viz. A connection from
the heater terminal marked Live Main Fan must be made to
one side of the fan motor contactor coil, the other side of the
coil being connected to Neutral. The fan motor electrical supply
must not be taken direct from the internal wiring of the NV
heater.
Notes for all systems.
i) Final overall length of adjustable disconnection piece must be
between 360 - 415mm.
ii) 45° offsets may be used if required. Each set is equivalent to
0.5m of flue length.
iii) Where NV heaters are used in clean environments it is permissible
to take the combustion air directly from the heated space. The
supplied mesh intake plate, must be fitted to the combustion air
inlet on the rear of the heater.
Fig 2b Individ al system - vertical
6m maximum
Terminal
Lengths Adjustable
lengths
Single to twin
adaptor
Flashing
Flue so ket
Combustion air
so ket
Condensate drain
length
Fig 2a Individ al system - horizontal
Terminal
Lengths
Adjustable
length
Single to twin
adaptor
Flue so ket
Combustion
air du t
6m maximum
Combustion
air so ket

9
5. Air Distribution System
5.1 General
NV/D models are designed for use with duct work to more
precisely define the point of air delivery, and /or provide ducted
return air or ducted fresh air inlet. All ducting must be
independently supported of the air heater.
Joints and seams of supply ducts and joints between NV ancillary
components must be securely fastened and made airtight using
appropriate sealants or sealing strips. If required the ductwork
should be insulated to reduce heat loss.
5.2 Noise Reduction
Ducting should be connected to the heater spigots via an airtight
flexible coupling of non-combustible material. Before fitting
the coupling it must be ensured that a minimum clearance of
approximately 15mm will be maintained between the ends of
the ducting and the heater spigots.
Sound attenuators may be fitted in inlet and outlet ducts to
reduce airborne fan noise. Materials used in outlet sound
attenuators must be capable of withstanding 100°C air
temperature without any deterioration.
5.3 Room Thermostat Siting
The room thermostat should be fitted at a point which will be
generally representative of the heated area as far as temperature
is concerned. Draughty areas, areas subjected to direct heat e.g.
from the sun, and areas where the air movement is relatively
stagnant e.g. in recesses, are all positions to be avoided for
siting the thermostat.
The thermostat should be mounted about 1.5m from the floor.
Any room thermostat, frost thermostat, time clock etc. must be
suitable for switching 230V, 5A and must be of the 'snap action'
type to minimise contact bounce.
For electrical connections of external controls see the
accompanying wiring diagram.
6. Commissioning & Testing
6.1 lectrical Installation
Checks to ensure electrical safety must be carried out by a
qualified person.
6.2 Gas Installation
The whole of the gas installation, including the meter, should
be inspected and tested for soundness and purged in accordance
with the recommendations of IGE/UP/1 (Edition 2) or
IGE/UP/2A as appropriate.
6.3 Air Distribution System
The system should be checked to ensure that the installation
work has been carried out in accordance with the design
requirements.
Particular attention should be given to the correct arrangement
of delivery ducts and registers, return air ducts and grills and
general adequacy of return air paths.
For NV/D units ensure that the ductwork is balanced so that
the specified motor running currents are achieved.
6.4 Checks before lighting the Air Heater
The following preliminary checks should be made before lighting
the heater(s)
a) Ensure that the ELECT ICAL supply to the heater is
switched OFF.
b) Check that all warm air delivery outlets are open.
c) Check that the thermostat is set at MAX.
d) Check that the clock control is set to an ON period.
e) Check that any other controls are calling for heat.
f) If a Eurotrol or Powrtrol is being used ensure that the
Summer/Winter switch is in the Winter position.
g) Check that the overheat reset button has not operated.
6.5 Lighting the Air Heater
NOTES:
1. On initial lighting of the heater(s), it may take some time to
purge the internal pipework of air.
IMPORTANT:
The internal pipework of the appliance has been tested for
soundness before leaving the factory. After establishing the
main burners test round the gas inlet connection using a leak
detection fluid e.g. soap solution.
Fig re 3 General Controls Layo t
Exhaust
Fan
Burner
Assembly
Printed
Cir uit Board
Gas
Valve
Lo al Lo kout
Indi ator and Reset
Ignition
Ele trode
Re tifi ation
Ele trode
Limit Thermostat
Bra ket
Pressure
Swit h

10
Fig re 4
Governor adjustment screw
under cover cap
(Honeywell
V 425AB1007)
Fig re 5
Governor adjustment screw
under cover cap
(Honeywell V 4605A
B1027)
6.5.1 All Models
1. Switch on the electrical supply at the isolator and the ignition
sequence will commence. After a delay of approximately 45
seconds the ignition spark will be generated and the main gas
valves energized. The burners will then light.
2. If the burners fail to light the control box will go to lockout
and the lockout light on the internal pcb will be illuminated. To
restart the ignition sequence depress the reset button adjacent
to the lockout light for about 5 seconds.
Note: A secondary red LED mounted on the pcb surface signals
as follows
a) 1 flash at power up as voltage is stabalising
b) 1 Hz flash signals safety shut down or over voltage greater
than 260V. If the heater is running and the air pressure signal
is lost the LED will flash at 1Hz. If the air pressure signal then
re-establishes the unit will restart after approximately six minutes.
If, when the air pressure signal is lost, the unit is turned off and
then back on the normal startup sequence will take place.
c) 2Hz flash signals undervoltage, less than 200V
3. SHUT OFF
Switch OFF the electrical supply to the heater or set the clock
control to OFF or set the room thermostat to MIN.
6.6 Adjustments
6.6.1 Burner Gas Pressure
This is set for the required heat input before despatch. In the
case of Hi/Lo and Modulating units both high and low pressures
are set. Pressures should be checked in the following manner.
6.6.1.1 Standard Units
1. Set external controls to ensure that the main burner is off.
Open the side access door. Connect a pressure gauge to the
burner pressure test point on the multifunctional control.
2. Set external controls so as to turn on the main burner. Compare
the measured burner gas pressure to that stated on the data plate.
If necessary adjust the burner gas pressure by turning the
regulator screw anticlockwise to decrease the pressure, or
clockwise to increase the pressure.
3. In addition it is advisable to check the gas rate using the gas
meter dial pointer. Ensure that no other appliances supplied
through the meter are in operation.
If required, after checking or setting the burner pressures, the
CO2 content in the flue gases can be checked by sampling in
the first section of flue fitted to the flue outlet of the unit.
Nominal CO2 values are given for guidance in the Table at the
bottom of the page.
5. Turn off the main burner as in 6.5.1. and disconnect the
pressure gauge and replace the sealing screw. Turn on the main
burner as above and test for gas soundness around pressure test
joint using a leak detection fluid e.g. soap solution.
6.6.1.2 High/Lo Regulator
1. Set external controls to ensure the main burner is off. emove
the side access panel. Connect a pressure gauge to the burner
pressure test point on the multifunctional control.
2. Set external controls to turn on the main burner and maintain
high fire. Compare the measured burner gas pressure to that
stated on the data plate. In addition it is advisable to check the
gas rate using the gas meter dial pointer ensuring that no other
appliances supplied through the meter are in operation.
3. epeat 2 above with external controls set to maintain low
fire.
4. If it is necessary to adjust either the high fire or low fire
pressures proceed as follows after levering off the plastic cover
from the Hi/Lo regulator.
Note: High fire setting must be adjusted first after which the
low fire setting can be set. Any adjustment of the high fire
setting alters the minimum setting. If it is only necessary to
adjust the low fire pressure setting proceed from step ii).
i) With the controls set to high fire use a 6mm hexagon wrench
or 10mm screwdriver to turn adjustment screw for high fire
pressure clockwise to increase and counter-clockwise to decrease
until the required pressure is obtained. Turn the burner On and
OFF several times to check the pressure setting and then turn
off.
ii) Disconnect electrical connection of high/low regulator and
turn burners back on and wait until the burner pressure has
stabalised. Use a 3.5mm screwdriver to turn adjustment screw
for low fire pressure clockwise to increase and counter-clockwise
to decrease until the required pressure is obtained.
NV NV NV NV NV NV NV NV NV NV NV NV NV
Model 10 15 20 25 30 35 40 50 60 75 90 120 140
Natural Gas G20
High Fire CO2% 6.7 7.3 7.4 7.3 7.8 8.25 7.7 8.7 8.1 8.8 7.4 8.7 8.3
Low Fire CO2% 3.7 3.1 3.2 3.7 3.7 3.6 3.6 3.5 3.4 3.6 3.9 4.4 4.6
Propane G31
High Fire CO2% 7.3 7.9 8.5 8.1 9.1 9.2 9.3 9.5 9.1 9.7 8.5 10.1 8.0
Low Fire CO2% 4.1 3.8 3.7 4.1 4.1 3.9 4.3 4.0 3.9 4.1 4.5 5.0 4.0
Fig 6 High/Low Reg lator
Cover
Lever point
Adjustment s rew for
maximum pressure
setting
Adjustment s rew for
minimum pressure
setting

2.5mm
11
iii) econnect high/low regulator and check high fire pressure.
iv) epeat from step i) if necessary.
v) eplace cover cap.
5. Turn off the main burner as in 6.5.1 disconnect the pressure
gauge and replace the sealing screw. Turn on the main burner
as in 6.5.1 and test for gas soundness around pressure test joint
using a leak detection fluid. eplace access panel.
6.6.1.3 Modulating Regulator
1. Set external controls to ensure that the main burner is off.
emove the side access panel. Connect a pressure gauge to the
burner pressure test point on the multifunctional control.
2. Set external controls so as to turn on the main burner and
maintain high fire. Compare the measured burner gas pressure
to that stated on the data plate. In addition it is advisable to
check the gas rate using the gas meter dial pointer ensuring that
no other appliances supplied through the meter are in operation.
3. epeat 2 above with external controls set to maintain low
fire.
4. If it is necessary to adjust either the high fire or low fire
pressures proceed as follows after removing the plastic cover
from the Modulating regulator.
Note: High fire setting must be adjusted first after which the
low fire setting can be set. Any adjustment of the high fire
setting alters the minimum setting. If it is only necessary to
adjust the low fire pressure setting proceed from step 4.ii.
i) With the controls set to high fire turn adjustment nut for high
fire pressure clockwise to increase and counter-clockwise to
decrease until the required pressure is obtained. Turn the burner
On and OFF several times to check the pressure setting and
then turn off.
ii) Disconnect electrical connection of modulating regulator
and turn burners back on and wait until the burner pressure has
stabalised. Turn adjustment nut for low fire pressure clockwise
to increase and counter-clockwise to decrease until the required
pressure is obtained.
iii) econnect modulating regulator and check high fire pressure.
iv) epeat from step i) if necessary.
v) eplace cover cap.
5. Turn off the main burner as in 6.5.1 disconnect the pressure
gauge and replace the sealing screw. Turn on the main burner
as in 6.5.1 and test for gas soundness around pressure test joint
using a leak detection fluid. eplace access panel.
6.6.2 Air Heater Controls
1. Close the gas service tap and ensure that the gas valve is
heard to close within 1 second and that the lockout light is
illuminated. Note that the heater may attempt one reignition
before going to lockout. Open the gas service tap and reset the
unit from lockout.
2. Check that the room thermostat and all automatic controls
are operating satisfactorily.
6.7 Handing over the Air Heater
Hand these instructions to the user or purchaser for retention
and instruct in the efficient and safe operation of the air heater
and associated controls.
Adjust the automatic controls to those values required by the
User.
Finally, advise the user or purchaser that, for continued efficient
and safe operation of the air heater, it is important that servicing
is carried out annually.
In the event that the premises are not yet occupied turn off the
gas and electricity supplies and leave instructional literature
adjacent to gas meter.
7. Servicing
WA NING: Always switch off and disconnect electricity supply
and close the gas service valve before carrying out any servicing
work or replacement of failed components.
NOTE:
If a suspended air heater is to be serviced do not lean ladders
against the heater. Ensure that an access tower or equivalent is
used.
7.1 General
Full maintenance should be undertaken not less than once per
year by a qualified person. After any servicing work has been
complete or any component replaced the air heater(s) must be
fully commissioned and tested for soundness as described in
Section 6.
7.2 Main Burner Assembly Removal
1. Ensure that the gas service valve is turned OFF and then
unscrew the union nut situated immediately down stream of it.
2. Disconnect the spark and rectification leads from the electrodes
and remove the electrical plug connections from the top of the
gas control valve assembly.
3. If required remove the manifold by removing the four screws
securing it to the burner assembly.
4. emove the two screws that secure the top of the burner
assembly to the bulkhead and lift out burner assembly
5. Using a stiff brush, not a wire brush, brush the burners to
dislodge accumulated deposits. Inspect the burners both internally
and externally to ensure that they are clean. Examine the injectors
and if damaged or deteriorated, replace with new ones of the
correct size and marking. If deemed necessary, clean the injectors.
Do not broach out with wire.
6. eassemble the injectors, manifold and burners in reverse
order to that above.
7.3 Ignition and Rectification lectrodes
1. Inspect the electrodes, making sure that they are in a sound
and clean condition. In particular check that the ignition electrode
is clean and undamaged. Check that the spark gap is 2.5mm
and that the rectification probe is 10 - 12mm forward of the
burner.
Fig 8 Ignition Electrode Spark Gap
Fig 7 Mod lating Reg lator
O ring
Adjustment nut (9mm)
for maximum pressure setting
Adjustment nut (7mm)
for minimum pressure setting
Cap
Shaft
6.3mm AMP terminals

12
7.4 Heat xchanger
Whilst the main burner assembly is removed from the unit
check that the primary sections that the burners fire into are
clean.
7.5 Main Fan Assembly
7.5.1 NV/F Models
1. Inspect the fan blades to see that they are not damaged and
that there is no excessive build up of deposits that could give
rise to an imbalance. Should it be necessary to remove the
assembly for cleaning proceed as follows.
2. Slacken the cable gland on the heater casing through which
the fan electrical cable passes.
3. Disconnect the fan leads from the electrical terminals on the
pcb.
4. Withdraw cable through entry grommet.
5. emove the fan and motor assembly complete by removing
the four hexagon headed bolts that secure the fan to the rear
panel.
6. eassemble in reverse order.
7.5.2 Centrifugal Fan/Silencer Section
1. emove section side panel(s) and inspect the fan blades to
see that they are not damaged and that there is no build up of
excessive deposits that could give rise to an imbalance. Should
it be necessary to remove the assembly for cleaning proceed as
follows.
2. Slacken the cable gland on the casing through which the fan
electrical cable passes.
3. Disconnect the fan leads from the electrical terminals in the
contactor enclosure.
4. Withdraw cable through entry grommet.
5. emove the complete fan assembly by removing the fixings
securing the fan to the base rails.
6. eassemble in reverse order.
7.6 Replacement of Faulty Components
7.6.1 Multifunctional Control
1. emove the burner assembly as previously described in
Section 7.2
2. elease the flanged connections at the inlet and outlet of the
multifunctional control and remove the multifunctional control.
3. econnect the new valve in the reverse order to that above
ensuring that the valve is correctly orientated. enew the sealing
'O' rings if necessary.
7.6.2 Burners
1. emove the burner assembly as described in Section 7.2.
2. emove the end plates of the burner assembly and the central
burner support plate.
3. Exchange burners as required and reassemble components
in reverse order.
4. e-commission the appliance as described in Section 6.
7.6.3 lectrode Assemblies
1. Disconnect the electrode leads from the pcb terminal as
appropriate.
2. emove the screw securing the electrode assembly to the
burner assembly side plate and withdraw the assembly.
3. Fit replacement and reassemble in reverse order. Check that
the spark gap is 2.5mm (See Fig. 8) and the rectification electrode
is 10 - 12mm forward of the burner.
7.6.4 Limit Thermostat
NB. Ensure that the thermostats are set correctly before fitment
Limit Thermostat settings:-
NV 10, 25 - 140 90°C
NV 15 and 20 100°C
NV 35 110°C
1. emove the screws securing the thermostat phial mounting
plate to the inner bulkhead, withdraw assembly and unclip the
phial.
2. emove the electrical connections from the limit thermostat.
emove the securing nut and remove thermostat from the front
panel.
3. Fit replacement thermostat in reverse order.
7.6.5 High Temperature Thermostat
1. Note their positions and then remove the electrical connections
from the high temperature thermostat. emove the two securing
screws and remove thermostat from the bulk head.
2. Fit replacement thermostat in reverse order.
7.6.5 xhaust Fan
1. emove the four screws securing the flue outlet socket.
2. Disconnect the fan electrical connections from the terminals
on the pcb.
3. emove the two screws at the left hand side of the fan
mounting plate that secure it to the exhaust header.
4. emove fan assembly by pulling forwards and to the left to
disengage the retaining lugs.
5. If needed transfer the fan mounting box to the replacement
fan.
6. Fit replacement exhaust fan, using new gaskets and silicon
sealant as necessary, and reassemble in reverse order.
7.6.6 Air Pressure Switch
1. Disconnect electrical connections.
2. Pull off the sensing tube from the air pressure switch.
3. Note the setting of the old pressure switch.
4. emove the screws fixing the air pressure switch and remove
switch.
4. Fit replacement in reverse order refitting the sensing tube to
the negative (- or L) tapping on the pressure switch. Adjust
setting to that of the old pressure switch.
7.6.7 Printed Circuit Board (pcb)
1. Disconnect all electrical connections.
2. At each of the five pcb mounting posts squeeze in the retention
tag and release the pcb. When all five have been released remove
the pcb from its five mounting posts.
3. Fit replacement in reverse order.
7.6.8 Centrifugal Fan/Motor
1. Disconnect the electrical connections to the centrifugal fan
section.
2. emove the side panels of the section for access to the fan
and motor.
3. Fit replacements as appropriate and reassemble in reverse
order.
Note: If a 3ph motor is being replaced ensure that the direction
of rotation is correct. If it is not interchange any two of the three
phases connected to the motor.

13
8. Connections to xternal Controls
Note:
To achieve maximum system efficiency it is recommended that NV units are controlled by an MC200 Fuel Saver unit. Simple room
thermostat and room thermostat/timeclock control systems will not provide optimum system efficiency and fuel savings.
NV H AT R (ON/OFF)
NEUTRAL
LIVE
EARTH
L
H AT
L/O
N
N
R/S
L
L
L
L MAIN
FAN
L MAIN
FAN
N MAIN
FAN
N CAP
N
Remote Sensor
(optional)
T1 3 T2 1
MC200 FU L SAV R
N
R S T
IN 2
COM
S N 1
0-10V+
0-10V-
Lockout
Fan In
Heat Hi In
Heat Hi Out
Heat Lo In
Heat Lo Out
L
Fan Out
L Out
SUPPLY IN Mod Out
1
2
3
4
5
6
7
8
9
11
12
14
17
16
15
13
10
NV H AT R (Hi/Lo)
NEUTRAL
LIVE
EARTH
L
H AT
L/O
N
N
R/S
L
L
L
L MAIN
FAN
L MAIN
FAN
N MAIN
FAN
N CAP
N
Remote Sensor
(optional)
T1 3 T2 1
MC200 FU L SAV R
N
R S T
IN 2
COM
S N 1
0-10V+
0-10V-
Lockout
Fan In
Heat Hi In
Heat Hi Out
Heat Lo In
Heat Lo Out
L
Fan Out
L Out
SUPPLY IN Mod Out
1
2
3
4
5
6
7
8
9
11
12
14
17
16
15
13
10
HL
HL
ON/OFF NV Hi/Lo NV
NEUTRAL
LIVE
EARTH
NV H AT R (Modulating)
L
H AT
L/O
N N
R/S
L L L
L MAIN
FAN
L MAIN
FAN
N MAIN
FAN
N CAP
N
MC200 FU L SAV R
N
R S T
IN 2
COM
S N 1
0-10V+
0-10V-
Lockout
Fan In
Heat Hi In
Heat Hi Out
Heat Lo In
Heat Lo Out
L
Fan Out
L Out
SUPPLY IN Mod Out
1
2
3
4
5
6
7
8
9
11
12
14
17
16
15
13
10
1
2
Remote Sensor
(optional)
T1 3 T2 1
Modulating NV
Note: The NV Heater
and MC200 may be fed
by separate ele tri al
supplies providing both
supplies are the same
phase.

14
TIM
SWITCH
ROOM
STAT
RF
Lockout Indicator
Push Button
Reset L/O
R/S
N
230V
NV H AT R
NEUTRAL
LIVE
EARTH
L
H AT
L/O
N
N
R/S
L
L
L
L MAIN
FAN
L MAIN
FAN
N MAIN
FAN
N CAP
N
L
N
Lin
Lout
N
Lout
Lin
ROOM
STAT
RF
Lockout Indicator
Push Button
Reset L/O
R/S
N
230V
NV H AT R
NEUTRAL
LIVE
EARTH
L
H AT
L/O
N
N
R/S
L
L
L
L MAIN
FAN
L MAIN
FAN
N MAIN
FAN
N CAP
N
N
Lout
Lin
Note: The NV Heater and Powrtrol, or time
lo k, may be fed by separate ele tri al
supplies providing both supplies are the same
phase.
NEUTRAL
LIVE
EARTH
NV H AT R
L
H AT
L/O
N
N
R/S
L
L
L
L MAIN
FAN
L MAIN
FAN
N MAIN
FAN
N CAP
N

9. Fault Finding Flow Chart
Digital Powrmati Control Board - Part number 427301 Issue 1 20/01/09 - Additional Diagnosti Aid
The PCB has two LEDs, A large LED labelled LOCKOUT next to the RESET Swit h and a small DIAGNOSTIC LED lose to CON11.
Gas & Ele tri al
supplies present at heater
Yes No Turn supplies on
Che k fuses/ onne tions
Lo k out light on
after 3 se s.
Exhaust fan runs
Faulty gas valve.
Che k/repla e
resistor (470k 0.6w
1%) on PCB
between gas valve
2 live & neutral
230V at Heat terminal on PCB Che k ontrol ir uit (Time lo k/thermostats) alling for heatNo
Yes
Voltage at limit stat 1 on PCB Che k Fuse 1 Ok Faulty PCBNo
Che k limit stats, reset manual stat. Che k onne tions
No
Yes
Yes Ok
230V to air pressure
swit h ommon No Faulty PCB
Yes
230V to air pressure
swit h N.O. No 230V to exhaust fan
Pressure swit h sensing
pressure. Adjust set
point/repla e
Repla e exhaust
fan
YesYes
230V to air pressure
swit h N.O. No
Yes
Che k pressure sensing tube. Adjust pressure swit h set point.
Change pressure swit h
Yes
Yes
Yes
Gas valve opens 230V to gas valve Faulty PCBNo No
Ignition sparks Che k/repla e re tifi ation probe. Faulty PCBNo
Yes Yes Faulty gas valve
Burners light Che k gas pressures. Repla e gas valveNo
Che k spark
probe/lead.
Faulty PCB
Burners remain
alight 3 ignition attempts then goes to lo k out.No
Main fan runs 230V at main
fan motor
Che k onne tions. Che k onta tor
Reset overload. Faulty PCB
No No
Repla e motor or fan/motor assemblyYesYes
Heater working orre tly
Exhaust fan runs Che k fuse 2 Repla e
No Failed
START
Yes Failed Repla e
Voltage at limit stat 2 on PCB
Lo kout LED OFF
Diagnosti LED
Flashing
Reason
Mains voltage too
low/high
StatusIndi ator Che k
Control is in
safety shutdown APS fault during
start-up
False flame
dete ted
Initial A tion
Measure mains voltage
Wait at least 5 mins to
see if fault self lears
Che k operation of
ombustion fan and APS
Che k burners for flame
Mains voltage is between
195 and 253V~
Final A tion
If ele tri ity supply is okay and
ombustion fan / APS operate
normally and no false flame is
present but fault persists then
repla e ontrol board
Both LEDs OFF
but burners should
be lit.
Control is in
standby
Call for heat ok, limit stat ok,
fuses ok
If heater still will not start repla e
p b
No heat demand
Limit stat tripped
F1 Blown
F2 Blown
Confirm all for heat
Reset Limit stat onfirm ok
Che k F1 - 3.15A fuse
Che k F2 - 3.15A fuse
15

16
ITEM USAGE PART #
MFC - Honeywell V 4605AB1027 10-90 145035204
MFC - Honeywell V 425AB1007 120/140 141378715
Ignition Electrode 10-75 142423002
Ignition Electrode 90-140 142423004
ectification Electrode 10-140 142423003
Burner - Bray P51 AB 19001 10-75 142400240
Burner - Bray P51 AB 19002 90-140 142400241
Thermostat - Limit - Imit LS1 - 90/110°C All 142403609
Thermostat - High temperature - Klixon TOD60T13- 60°C All 143000310
Main PCB All 142403610/3
Hi/Lo Governor Head - Honeywell V4336A 10-140 -/HL 142466402
Modulating Governor Head - Honeywell V7335A 10-140 -/MOD 142466403
Modulating Driver - Honeywell QM100A1009 10-140 -/MOD 142400305
Exhaust Fan - Sifan WFFB 0223-006 10-50 140210499
Exhaust Fan - Torin 077446 DSA424-215 60/75 140201505
Exhaust Fan - Torin 077445 DSF180-042 90-140 140201506
Dungs Pressure Switch LGW3 A2 All 146522174
Contactor - Danfoss CI-4-5-10 90-140, All -/C 143016131
10. Short List of Parts
Only originally specified parts may be fitted as service replacements and all items are available from the Powrmatic Ltd Spares
Department. Please refer to Powrmatic Ltd for any parts not shown in the listing.