Ambirad T Series Guide

Mfg No. 144662 Rev. 2, Page 1
Installation Form WA/010/0501
This appliance is for use with natural or propane gas. Read these
instructions thoroughly before commencing installation.
0063
APPLIES TO: Installation, Commissioning, and Service
4.3 Fitting the Flue
4.4 Gas Connection
4.5 Electrical Connections
4.6 Room Thermostat Siting
5.0 Air Distribution Systems
5.1 Horizontal Louvres
5.2 Vertical Louvres (Option)
5.3 Downturn Air Nozzles (Option)
5.4 Fitting Outlet Duct - Models TB, TE
5.5 Fitting Return Air Duct - Model TE
6.0 Commissioning and Testing
6.1 Electrical Check
6.2 Gas Connection
6.3 Suspension and Support
6.4 Lighting the Heater
6.5 Heater Pipework
6.6 Adjustments - Main Burner and Pilot
6.7 Air Distribution System
6.8 Heater Controls
6.9 Handing Over
7.0 Servicing Instructions
7.1 Requirements and Procedure
Table of Contents
1.0 Introduction
1.1 Basic Information
1.2 Warranty
2.0 Technical Data
2.1 Specifications
2.1.1 TA Specifications
2.1.2 TB and TE Specifications
2.2 Burner Injector Size and Pressure
2.3 Dimensions
2.3.1 Dimensions - TA Models
2.3.2 Dimensions - TB Models
2.3.3 Dimensions - TE Models
3.0 General Requirements
3.1 Related Documents
3.2 Heater Locations
3.3 Flue System
3.4 Gas Supply
3.5 Air Distribution System
3.6 Electrical Supply
4.0 Installation
4.1 Uncrating and Preparation
4.2 Fitting the Heater
AMBI-RAD
Models TA, TB, TE
Gas-Fired Unit Heaters
Warranty is void if ...
a. Heater is installed in atmospheres containing flammable
vapoursoratmospherescontainingchlorinatedorhalogenated
hydrocarbons or atmospheres containing any silicone, alumi-
num oxide, etc. that adheres to spark ignition flame sensing
probes.
b. The installation is not in accordance with these instructions.
c. Axial fan-type unit heater, is connected to a duct system or
fitted with a non-factory authorised air distribution device.
d. Fitted in the printing industry where fine starch or sugar dusts
are used.
1.0 INTRODUCTION
1.1 Basic Information
The instructions in this manual apply to Model T Series warm air
heaters. Model TA heaters have an axial fan for air delivery. Models
TB and TE have a centrifugal blower for air delivery and are in-
tended for installation with or without ductwork. Model TE heaters
include a blower cabinet. The T Series heaters are designed for ei-
ther overhead suspension or mounting on a non-combustible sur-
face and are suitable for indoor installation only.
A permanent electricity supply of 230 volts, 50 Hz, single phase is
required for all TA Models. Models TB and TE may use either single
phase or three phase.
Models T Series heaters are approved for:
Type B11- Gravity Vent, Open Flue
Category II2H3P - use with G20 natural gas or G31 propane gas
Each unit is fitted with a permanent pilot. A thermoelectric flame
supervision device monitors the pilot flame to prevent an explosive
condition occurring.
When the required room temperature is reached, the main burner
will shut down leaving the fan running to cool down the heat ex-
changer. When cool enough, the fan thermostat will turn off the fan.
1.2 Warranty
8.0 Removal and Replacement of Parts
8.1 Main Burner
8.2 Pilot Burner Injector
8.3 Pilot Burner Assembly
8.4 Pilot Ignition System (Optional)
8.5 Main Burner Injectors
8.6 Blower Motor - TB, TE
8.7 Fan Motor/Blade - TA
8.8 Multifunctional Control Valve
8.9 Limit and High Temperature
Limit Controls
8.10 Fan Temperature Control
9.0 Circuit Diagrams
9.1 Site Wiring Connections
9.2 Model TA
9.3 Models TB and TE
10.0 Fault Finding Charts
11.0 Exploded Diagrams
12.0 Short List of Parts
HAZARD INTENSITY LEVELS
1. DANGER: Failure to comply will result in severe
personal injury or death and/or property damage.
2. WARNING: Failure to comply could result in severe
personal injury or death and/or property damage.
3. CAUTION: Failure to comply could result in minor
personal injury and/or property damage.
WARNING:Theelectricalisolatorshouldonly
be used in an emergency and should not be
used for closing down the main burner, as it
switches off the fan prematurely and may
damage the heat exchanger, invalidating the
warranty.
PLEASE READ THESE INSTRUCTIONS
THOROUGHLY BEFORE COMMENCING
WORK.
WARNING: Improper installation, adjust-
ment, alteration, service or maintenance can
cause injury or property damage. All work
mustbecarriedoutby competent persons, i.e.
a registered CORGI installer.

Form WA/010, Page 2
2.0 TECHNICAL DATA
2.1 Specifications
2.1.2 TABLE2C - ELECTRICAL SPECIFICATIONS of Model TB or TE with OPTIONAL MOTOR
Blower kw 0.375 0.56 0.73 1.12 0.75 1.12 1.5 2.25
Motor HP 0.5 0.75 1 1.5 1 1.5 2 3
Voltage 220-240 V,1 PH,50 Hz 400-415 V,3 Ph, 50 Hz
Starting Current 20.1 26 37.5 41.7 12.4 17.2 22.3 27.3
Running Current 5.4 5.6 7.5 7.8 2.0 2.8 3.4 4.9
Power Consumption 696 879 1025 1429 1023 1459 1831 2750
Fuse Size 10 10 15 15 5 5 7.5 7.5
2.1.2 TABLE2B - STANDARD MOTOR SIZE, Model TB or TE
TB or TE Blower Motor
Size kw HP
75, 100, 125, 150, 175 0.375 0.5
200, 225 0.56 0.75
250, 300 0.73 1
350, 355, 400 1.12 1.5
2.1.1 TABLE 1 - Model TA SPECIFICATIONS
Size Heat Input Heat Output Maximum Gas Rate
! for G20
Natural Gas
Maximum Gas
Rate #for G31
Propane Gas Air Volume Running Power $ Fuse
kw BTUH kw BTUH m3/hr m3/hr m3/hr Amps$Consumption Size
100 29.3 100,000 23.1 79,000 2.73 1.11 2040 1.0 240 2
125 36.6 125,000 28.9 98,750 3.41 1.39 2460 1.0 240 2
150 43.9 150,000 35.1 120,000 4.10 1.67 3300 1.0 240 2
175 51.3 175,000 40.5 138,250 4.78 1.95 3300 1.0 240 2
200 58.6 200,000 46.9 160,000 5.46 2.23 4260 1.5 375 5
225 65.9 225,000 52.1 177,750 6.15 2.50 4260 1.5 375 5
250 73.2 250,000 58.6 200,000 6.83 2.78 5700 2.0 480 5
300 87.9 300,000 69.4 237,000 8.20 3.34 5700 2.0 480 5
350 102.5 350,000 81.0 276,500 8.57 3.90 6600 2.9 750 7.5
355 102.5 350,000 81.0 276,500 8.57 3.90 7560 2.9 750 7.5
400 117.1 400,000 92.5 316,000 10.95 4.45 7560 2.9 750 7.5
!G as flow ra te is based ona gas with a gross C.V.of39.9 MJ/m3(1030 BTUH)and includes a pilotflow ra te of351 watts (1200 BTUH)
#G as flow ra te is based ona gas with a gross C.V.of101.6 MJ/m3(2500 BTUH)and includes a pilotflow ra te of351 watts (1200 BTUH)
$B ased onnorm aloperationat240 volts and 50 hertz.
2.1.2 TABLE2A - Model TB andModel TESPECIFICATIONS
Size
Heat Input Heat Output
Maximum
Gas Rate!
for G20
Natural Gas
Maximum
Gas Rate #
for G31
Pro
p
ane Gas
Blower
$
Air Volume%
Free Blow
Air
Volume&Flow
@ 125 Pa '
Running ' Power
'
Fuse
kw BTUH kw BTUH m3/hr m3/hr RPM m3/hr Rise oCm
3/hr Rise oCAmps Consumption Size
75 22.0 75,000 17.6 60,000 2.05 0.83 550 2900 18 2050 26 5.4 696 10
100 29.3 100,000 23.1 79,000 2.73 1.11 710 3650 19 2400 29 5.4 696 10
125 36.6 125,000 28.9 98,750 3.41 1.39 710 3650 23 2900 30 5.4 696 10
150 43.9 150,000 35.1 120,000 4.10 1.67 670 4700 25 2900 36 5.4 696 10
175 51.3 175,000 40.5 138,250 4.78 1.95 670 4700 29 2900 42 5.4 696 10
200 58.6 200,000 46.9 160,000 5.46 2.23 700 4600 30 3750 37 5.6 879 10
225 65.9 225,000 52.1 177,750 6.15 2.50 700 4600 34 3750 42 5.6 879 10
250 73.2 250,000 58.6 200,000 6.83 2.78 800 6400 27 5250 33 7.5 1025 15
300 87.9 300,000 69.4 237,000 8.20 3.34 800 6400 33 5250 40 7.5 1025 15
350 102.5 350,000 81.0 276,500 8.57 3.90 810 8400 29 7500 33 7.8 1429 15
355 102.5 350,000 81.0 276,500 8.57 3.90 770 8850 28 8150 30 7.8 1429 15
400 117.1 400,000 92.5 316,000 10.95 4.45 770 8850 32 8150 34 7.8 1429 15
!Gasflowrate is based on a gas with a C.V. of 39.9 MJ/m3(1030 BTUH) andincludes a pilot flow rate of 351 watts (1200 BTUH)
#Gasflowrate is based on a gas with a C.V. of 101.6 MJ/m3(2500 BTUH) and includes a pilot flow rate of 351 watts (1200 BTUH)
$Approximate speed of factory setting of standard drive components.
%Approximate air performance at factory blower speed setting of standard drive components.
&Approximate air performance when standard drive components are at maximum setting.
'Based on normal operation at 240 volts and 50 hertz with standard motor. Refer to TA B LE 2 B , Optional Motor Table, for motor
amps and power consumption ratings when equipped with other-than-standard motors.

Mfg No. 144662 Rev. 2, Page 3
2.2 Burner Injector Size and Pressure
Natural Gas
2.2.1 TABLE3 - G20 (Natural) GAS INJECTOR SIZE, BURNER PRESSURE, AND
INLET PRESSURE
Size Injector Quantity
Injector
Size Injector
Marking Burner Pressure M inimum
Inlet
Pressure
Maximum
Inlet
Pressure
Gas Rate
Per Burner
mm mbar in. w.g. mbar mbar M3/Hr
75 4 2.10 45 8.5 3.4 12.5 30 0.52
100 4 2.35 42 8.5 3.4 12.5 30 0.69
125 5 2.35 42 8.5 3.4 12.5 30 0.69
150 7 2.20 44 9.0 3.6 14.0 30 0.59
175 7 2.35 42 8.5 3.4 16.0 30 0.69
200 9 2.25 43 8.5 3.4 12.5 30 0.61
225 9 2.35 42 8.5 3.4 12.5 30 0.69
250 12 2.20 44 8.5 3.4 15.0 30 0.57
300 12 2.35 42 8.5 3.4 15.0 30 0.69
350 14 2.35 42 8.5 3.4 17.0 30 0.69
355 16 2.35 42 7.0 2.8 17.0 30 0.60
400 16 2.35 42 8.5 3.4 17.5* 30 0.69
*When fitted with optional modulating burner control, Model 400 requires minimum inlet pressure of 19 mbar of natural gas.
Propane Gas
2.2.2 TABLE4 - G31 (Propane) GAS INJECTOR SIZE, BURNER PRESSUREAND
INLET PRESSURE
Size Injector
Quantity
Injector
Size Injector
Marking Burner Pressure M inimum
Inlet
Pressure
Maximum
Inlet
Pressure
Gas Rate
per Burner
mm mbar in. w.g. mbar mbar M3/Hr
75 4 1.20 1.20 21.5 8.6 27 35 0.21
100 4 1.45 1.45 21.5 8.6 27 35 0.28
125 5 1.45 1.45 21.5 8.6 27 35 0.28
150 7 1.35 1.35 21.5 8.6 27 35 0.24
175 7 1.45 1.45 21.5 8.6 28 35 0.28
200 9 1.40 54 21.5 8.6 28 35 0.25
225 9 1.45 1.45 21.5 8.6 28 35 0.28
250 12 1.35 1.35 21.5 8.6 30 35 0.23
300 12 1.45 1.45 21.5 8.6 30 35 0.28
350 14 1.45 1.45 21.5 8.6 30 35 0.28
355 16 1.35 1.35 21.5 8.6 30 35 0.24
400 16 1.45 1.45 21.5 8.6 30 35 0.28

Form WA/010, Page 4
2.3 DIMENSIONS
2.3.1 Dimensions of Standard Model with Axial-Fan for Air Delivery
ModelABCEFGHPR
TA mm mm mm mm mm mm mm mm mm
100 489 819 865 360 348 283 489 150
125 559 819 908 430 418 326 489 175
150 699 819 927 570 558 345 489 200
175 699 819 927 570 558 345 489 200
200 838 895 929 710 698 347 438 200
225 838 895 929 710 698 347 438 200
250 1048 895 921 919 908 339 438 200 432
300 1048 895 921 919 908 339 438 250 432
350 1187 895 929 1059 1048 347 438 250 508
355 1327 895 929 1199 1187 347 438 250 559
400 1327 895 929 1199 1187 347 438 250 559
Figure 2
TABLE 5
NOTE: Sizes 100-
225 have a single
axial fan. Sizes
250-400 have dual
fans.
501
56
70
41

Mfg No. 144662 Rev. 2, Page 5
2.3.2 Dimensions of Standard Model with Centrifugal Blower (less Cabinet) for Air Delivery
Model A B C D E F G H P
TB mm mm mm mm mm mm mm mm mm
75 489 819 1133 317 355 348 551 489 125
100 489 819 1133 317 355 348 551 489 150
125 559 819 1133 387 425 418 551 489 175
150 699 819 1226 527 565 558 644 489 200
175 699 819 1226 527 565 558 644 489 200
200 838 895 1226 667 705 698 644 438 200
225 838 895 1226 667 705 698 644 438 200
250 1048 895 1133 876 914 908 551 438 200
300 1048 895 1133 876 914 908 551 438 250
350 1187 895 1226 1016 1054 1048 644 438 250
355 1327 895 1226 1156 1194 1187 644 438 250
400 1327 895 1226 1156 1194 1187 644 438 250
TABLE 6
Figure 3
501
56
70
41

Form WA/010, Page 6
2.3 DIMENSIONS (cont'd)
2.3.3 Dimensions of Standard Model with a Blower Cabinet
Model A B D E F H J K P
TE mm mm mm mm mm mm mm mm mm
75 489 819 317 355 348 489 451 706 125
100 489 819 317 355 348 489 451 706 150
125 559 819 387 425 418 489 451 706 175
150 699 819 527 565 558 489 591 706 200
175 699 819 527 565 558 489 591 706 200
200 838 895 667 705 698 438 730 783 200
225 838 895 667 705 698 438 730 783 200
250 1048 895 876 914 908 438 940 783 200
300 1048 895 876 914 908 438 940 783 250
350 1187 895 1016 1054 1048 438 1080 783 250
355 1327 895 1156 1194 1187 438 1219 783 250
400 1327 895 1156 1194 1187 438 1219 783 250
Figure 4
TABLE 7
501
899
56
70
41

Mfg No. 144662 Rev. 2, Page 7
3.0 GENERAL REQUIREMENTS
3.3 Flue System
Each heater must be fitted with an adequately sized flue (See
Table 10). Stainless steel flue pipe is recommended.
WARNING: The flue must be installed in
accordance with BS5440 Part 1 1990 for all
modelsup to and including Size200 orBS6230
1991 for all Models Size 250 and over.
Failure to provide proper flueing could result
in death, serious injury and/or property
damage. The unit must be installed with a flue
to the outside of the building. Safe operation
ofanynatural draughtgas burningequipment
requires a properly operating flue system,
correct provision for combustion air, and
regular maintenance and inspection.
The unit heater is fitted with an integral draught diverter. Do
not use an external draught diverter, barometric damper and/
or restrictive damper.
When condensation is possible within the flue, double wall
fluepipeisrecommended.Whendouble wall flue pipe is used,
it should be a type complying with British Standards. Double
wall flue pipe requires the use of a special flue socket adapter.
Wherecondensationis unavoidable, provision should be made
for condensation to flow freely to a point at which it can be
released, preferably into a gulley. The condensation pipe from
the flue to the disposal point should be of non-corrodible ma-
terial, not less than 19 mm (3/4 in.) diameter.
CAUTION: Avoid installing a unit in an extremely
draughty area. Extreme draughts can shorten the life of
the heat exchanger and/or cause safety problems.
Refer to Table 9 for recommended mounting height. Air heaters with cen-
trifugal fans are designed for higher airflows. Downflow nozzles are rec-
ommended for heaters at upper mounting heights, and 90odownturn heads
for heaters mounted above these heights.
Units should always be arranged to blow toward or along exposed wall
surfaces, if possible. Where two or more units are installed in the same
room, a general scheme of air circulation should be maintained for best
results.
TABLE 9 - RECOMMENDED MOUNTING HEIGHTS (m)
Size 75-175 200-250 300-400
Axial Fan 2.5-3.0 2.5-3.5 3.0-3.5
Centrifugal Fan 2.5-4.0 3.0-4.0 3.0-5.0
TABLE 8 - REQUIRED CLEARANCES (mm) - All Sizes
Sides Bottom Rear
Top Control Other To
Combustibles To Non- Combustibles (Measuring from cabinet)
152 See Note 152 152 0 750
NOTE: Service Clearance for Control Side is the width of the unit
plus 152 mm in order to remove the drawer-type burner rack.
3.1 Related Documents
It is important that all gas appliances are installed by competent persons,
i.e. a registered CORGI installer, in accordance with the relevant require-
ments of the following regulations.
Failure to install appliances correctly could lead to prosecution. It is in
your own interest and that of safety to ensure compliance with the law.
THE RELEVANT REGULATIONS ARE ...
GAS SAFETY (INSTALLATIONS & USE) (Amendment) REGULA-
TIONS 1990
THE HEALTH AND SAFETY AT WORK, ETC. ACTS
·BS62301991 SPECIFICATION FOR THE INSTALLATION OF GAS
FIRED FORCED CONVECTION AIR HEATERS FOR COMMER-
CIALAND INDUSTRIAL SPACEHEATING OF RATED INPUT EX-
CEEDING 60 KW.
·BS5588PART1 (SECTION 1) 1990; PART21985 AND 1990; AND
PART 3 1983 AND 1989
·BS5440 PART 2 1989 FLUES AND AIR SUPPLY FOR GAS APPLI-
ANCES NOT EXCEEDING 60 KW
·BS6891 1988 LOW PRESSURE INSTALLATION PIPES
BRITISH GAS PUBLICATIONS
IGE/UP/1PURGING PROCEDURES FOR NON-DOMESTIC INSTAL-
LATIONS and SOUNDNESS TESTING PROCEDURES FOR IN-
DUSTRIAL INSTALLATIONS
I.E.E. REGULATIONS FOR ELECTRICAL INSTALLATIONS AND
THE REQUIREMENTS OF THE FOLLOWING...THE LOCAL
REGION OF BRITISH GAS Plc
WARNING: Air heaters should not be installed in
corrosive atmospheres, i.e., near plating or
degreasing plants or in areas where there is a fire
risk. Consult BS6230 for further information on
hazardous areas.
3.2 Heater Location
The location chosen for the heater must permit the provision of a satisfac-
tory combustion air and flue system. The location must also provide re-
quired clearances and adequate space for servicing.
Suspended heaters are most effective when located as close
to the working zone as possible. However, care should be
exercised to avoid directing the discharge air directly on the
room occupants.
Partitions, columns, counters, or other obstructions should
be taken into consideration when locating the unit heater so
that a minimum quantity of air will be deflected by any such
obstacles. When units are suspended in the centre of the space
tobe heated, the air should be dischargedalongexposedwalls.
In large areas, units should be located to discharge air along
exposed walls with extra units provided to discharge air in
toward the centre of the area. At those points where infiltra-
tion of cold air is excessive, such as at entrance doors and
loading doors, it is desirable to locate the unit(s) so tempered
air is discharged directly toward the source of cold air from a
distance of 4.5 to 6.0 meters. The use of downturn 30o, 60o, or
90onozzles is recommended for units at the higher mounting
heights.
Table 10 - Flue Diameter and Minimum Flue Height
Model Size Nominal Flue
Diameter
(
mm
)
Minimum Flue
Hei
g
ht
(
m
)
75 125 2
100 150 2
125 175 2
150 200 2
175 200 2
200 200 2
225 200 2
250 200 2.5
300 250 2
350 250 2.5
355 250 2.5
400 250 2.5

Form WA/010, Page 8
3.0 GENERAL REQUIREMENTS (cont'd)
4.0 INSTALLATION
4.1 Uncrating and Preparation
Prior to despatch, the unit was operated and tested at the
factory. If the heater has incurred any damage in shipment,
file a claim with AMBI-RAD within 48 hours.
Check the data plate for the gas specifications and electri-
cal characteristics of the heater to be sure that they are com-
patible with the gas and electric supplies at the installation
site. Read this booklet and become familiar with the instal-
lation requirements of your particular heater. Before be-
ginning, make preparations for necessary supplies, tools,
and manpower.
Check to see if there are any site-installed options that need
to be fitted on the heater prior to installation. Each of the
option packages includes a list of components and com-
plete, step-by-step instructions. For a brief explanation of
frequently specified site-installed options, see Section 5.
Afterbecomingfamiliarwiththe instructions, assemble and
install the options that are required for your heater.
4.2 Fitting the Heater
Before fitting the heater, check the supporting structure to
be used to verify that it has sufficient load-carrying capac-
ity to support the weight of the unit and the ancillary equip-
ment. See weights in Table 11.
Where the location of the air heater is such that it might suffer external me-
chanical damage, i.e., from overhead cranes, fork lift trucks, it must be suit-
ably protected.
When lifting a centrifugal-blower unit, support the blower and motor to pre-
vent the unit from tipping. When lifting a unit with a blower cabinet, support
the blower cabinet. Blower models may have legs to support the blower as-
sembly during shipping. After the unit is fitted at the site, these legs should be
removed.
Materialusedto support any heater whether suspended or base mounted should
be corrosion resistant and of sufficient strength. The gas supply pipe and
electrical connections should not support any of the weight of the heater.
WARNING:Unitsmustbe level forproperoperation.
Do not place or add additional weight to the heater.
The flue must terminate outside the building in a freely exposed
position so as to prevent products of combustion from entering any
opening in a building.
If the flue passes through a wall or ceiling of combustible material,
it must be enclosed by a sleeve of non-combustible material and
separated from the sleeve by at least 25 mm (1 inch) air gap. The
temperature of any combustible material near the flue or heater must
not exceed 65oC when the heater is in operation. The flue must also
be at least 50 mm (2 in.) from any other combustible material.
The joint between the female flue socket of the heater and the flue
mustbe sealed. If twinwallflue piping is used,theappropriate adapter
must be fitted.
The joints between the flue and the roof must be made good to pre-
vent water ingress.
3.4 Gas Supply Pressure
These heaters are designed to operate on either G20 natural gas or
G31 propane gas. Refer to Tables 3 and 4 or the data plate for mini-
mum and maximum supply pressure. Before installation, check that
the local distribution conditions, nature of gas and pressure, and
adjustment of the appliance are compatible.
The gas meter and service must be checked by the gas supplier to
ensure that it is adequate to deal with the total connected load of the
completed installation.
The installation must comply with British Standard 6891, and the
complete installation including the meter must be purged and tested
for soundness as described in the above standard and in British Gas
Document IGE/UP/1.
3.5 Air Distribution System
Recommendations for the air distribution system are given in the
document entitled “Standards of Installation for Gas Fired Indus-
trial Warm Air Heaters”.
The following notes are of particular importance...
“For free-blowing units, it must be taken into account that the buoy-
ancy of the heated air leaving the heater and air patterns with the
space being heated will modify the air throw pattern achieved.
In buildings having a low heat loss where single units are required
to cover a large floor area and in buildings with high roof or ceiling
heights, air recirculation may be fitted to ensure even heat distribu-
tion and minimise stratification respectively. Care should be taken
to avoid impeding the air throw with racking, partitions, plant ma-
chinery, etc.”
Various outlet configurations are available as optional extras to
modify the air throw pattern to suit particular site conditions. (See
Section 5).
3.6 Electrical Supply
Wiring external to the air heater must be installed in accordance
withlocal requirements and meet nationalregulations including I.E.E.
Regulations. Wiring must be carried out by a qualified electrician.
A constant 220-240V, 50 Hz single phase supply is required for all
heaters equipped with axial fan(s) for air delivery. Depending on the
electrical components, heaters with a centrifugal blower may use
either 220-240V, 50 Hz single phase or 415V, 50Hz three phase
supply. All heaters and controls must be correctly earthed. An isola-
tor with a contact separation of at least 3 mm on all poles should be
installed adjacent to the heater.
When a number of heaters are to be wired as part of a single instal-
lation, each heater must be provided with a separate isolator.
Electrical supply entrance is on the rear of the heater. The final con-
nection to the heater should be to the appliance terminal block in the
heater electrical box. See the connection diagram in Paragraph 9.1.
Supply cable size should be 1.0 mm for a model equipped with an
axial fan. Larger cable may be required for heaters with a centrifugal
blower. See Section 2, Technical Data, for required fuse size.
Fit the cord anchor supplied with the heater. The length of the con-
ductors between the cord anchorage and the terminals must be such
that the current-carrying conductors become taut before the earthing
conductor, if the cable or cord slips out of the cord anchorage.
TABLE 11 - NET WEIGHT OF HEATERS (approximate)
Model with Size
following type of
Air Delivery
Equ i pm e n t 75 100 125 150
175 200 225 250 300 350 355 400
With Axial Fan kg 80 86 93 118 146 166 191
With Blower kg 90 90 115 134 145 175 195 221
With Blower
and Cabinet kg 106 106 134 151 160 206 213 251

Mfg No. 144662 Rev. 2, Page 9
Figure 5 - Suspension
Dimensions
A
4.2 Fitting the Heater (cont'd)
4.2.1 Suspending the
Heater
Heaters are equipped with four suspen-
sion points to receive an M10 eyebolt
or threaded rod. See dimensions in Fig-
ure 5.
Blowermodels must besuspendedwith
rigidsupportmaterial.Donotusechain
or flexible support material for heaters
with centrifugal blowers. Blower mod-
els with a cabinet have six suspension
points.
WARNING: Suspend the
heater only from the
suspension points. Do not
suspend from the heater
side or top panel.
4.2.2 Mounting the Heater
These heaters may be base mounted on a non-combustible support.
Always ensure the heater is adequately secured.
4.3 Fitting the Flue System
The flue pipe system attaches directly to the flue socket provided on
the heater. The socket is sized to accept standard metric sheetmetal
flue pipe. When double wall flue pipe is used, a suitable adapter is
required.
It is recommended that a split socket is fitted so that if necessary the
heater may be removed for servicing.
Any joints should be secured using three pop rivets or sheradized
sheet metal screws at each joint. The joints of the flue must be sound.
The flue pipe should be supported so that the heater does not carry
any of the flue weight. Flues must be fitted with an approved flue
terminal.
4.4 Gas Connection
Fit the heater with the piping arrangement shown in Figure 6.
NOTE: When removed, the side access panel is designed to hang
from the bottom of the heater. Place the extended top edge of the
side panel over the lip on the bottom panel of the heater. The side
panel will "hang" suspended from the bottom panel until ready to be
re-installed on the heater.
Heaters suspended by flexible support material or drop rods should
be connected to the gas service using a flexible connector. Sufficient
slack must be provided in the flexible connector to allow for normal
movement of the heater. Use a flexible connector of suitable size to
reduce pressure drop and the possibility of flow noise.
Warning: Do not use the gas supply connection
to balance heater or support any weight of the
heater.
501
56
70
Heater Front
NOTE: Blower Models with a blower cabinet have six suspension
points. See additional dimensions on page 6.
Size A(mm)
75/100 348
125 418
150/175 558
200/225 698
250/300 908
350 1048
355/400 1187
Figure 6 - Recommended Gas Supply Piping
Arrangement
Top of Heater
Control Side
(access panel
removed)
Dotted lines indicate site provided piping
and connections

Form WA/010, Page 10
4.0 INSTALLATION (cont'd)
4.5 Electrical Connections
All electrical connections should be made in the heater terminal box
. Screw-type terminals are provided. Connections should be in ac-
cordance with terminal markings and the wiring diagram affixed to
the heater or shown in Section 9.
The minimum control scheme must have a room thermostat, and in
all cases, it is essential that the main input to terminals L and N
remains alive at all times to ensure the correct operation of the
fan/blower. Control panels that incorporate time and temperature
control and/or remote reset are available from AMBI-RAD.
Units fitted with automatic spark ignition may have a remote reset
facility by wiring to the terminal strip in the electrical box as indi-
cated on the wiring diagram. CAUTION: The cause for activating
the lockout control should be identified and corrected before reset-
ting. If the first reset is not successful, wait 15 seconds before push-
ing the reset button.
4.6 Room Thermostat Siting
The siting of the thermostat or panel is particularly important. It
should not be fitted on an outside wall. Avoid locating the thermo-
stat in draughty areas or where it may be directly exposed to heat
from the sun or other heat sources. The thermostat or panel should
be mounted on an internal wall or column about 1.5 m above the
floor. Follow the thermostat manufacturer’s instructions when fit-
ting a thermostat. The thermostat must be suitable for switching
240 volts.
Do not attempt to control more than one heater from a thermostat
or panel unless a properly wired relay is fitted. If correctly fitted
with relays, a thermostat or panel can be used to control several
heaters. An AMBI-RAD SU4 slave panel allows up to four heaters
to be controlled from a single panel.
5.0 AIR DISTRIBUTION SYSTEMS -- Standard and Optional
TABLE 13 - INLET DUCT CONNECTION SIZE (mm)
Heater Standard Blower Cabinet Optional Blower Cabinet
Size Width Height Width Height
75 - 100 -125 451 706 451 495
150 - 175 591 706 591 495
200 - 225 730 783 730 495
250 - 300 940 783 940 495
350 1080 783 1080 495
355 & 400 1219 783 1219 495
5.5 Fitting Return Air Ductwork -
Model TE
Return air (inlet) ducting may be attached to the blower cabinet.
The rear of the standard blower cabinet is totally open.
The cabinet is available with a smaller inlet opening with a spigot
or as a mixing box with two openings with spigots.
5.1 Horizontal Louvres
Model TA heaters are factory supplied with adjustable horizontal lou-
vres. Model TB and TE heaters are factory supplied less louvres for
direct attachment to ductwork. For free blowing applications, optional
horizontal louvre frames may be added to a Model TB or TE heater.
Horizontal louvres may be adjusted from 10 to 55 degrees to direct
the airflow down to the floor. IMPORTANT: Do not adjust the lou-
vres beyond their stops.
5.2 Optional Vertical Louvres
Louvre frames can be fitted with optional vertical louvres to increase
the air pattern spread. This option is normally used on heaters that are
installed at minimum mounting heights. The vertical louvre assem-
bly is designed to be assembled and fitted at the installation site.
5.3 Optional Downturn Air Nozzles
Heaters can be fitted with optional downturn nozzles to direct the
discharge air toward the floor. Downturn nozzles are recommended
for Sizes 75-175 installed above 3 m and Sizes 200-400 installed
above4m. Downturn nozzles should always be fitted to units mounted
above the recommended heights in Table 9.
A 30o downturn nozzle changes discharge air direction up to 57o. A
60odownturn nozzle changes discharge air direction up to 90o. A 30o
downturn nozzle may be used with vertical louvres. Do not fit verti-
cal louvres on an axial fan heater with a 60odownturn nozzle. When
vertical louvres are required with a 60onozzle, a centrifugal fan unit
must be used. A 90onozzle with optional two-way or four-way dis-
charge plenum is also available for centrifugal fan models.
All downturn nozzles are designed for site assembly and fitting.
5.4 Fitting Outlet Ductwork - Model TB and
Model TE
Low heat capacity materials should be used for the construction of
warm air delivery and should be insulated when passing through un-
heated spaces. Joints and seams of all outlet air ducts and fittings
must be securely fastened and made airtight.
It is good practice to fit an access door 250 mm high x 150 mm wide
in the side of the outlet duct, adjacent to the heater, to allow for ob-
servation of the heat exchanger at annual service.
TABLE 12 - OUTLET DUCT CONNECTION SIZE
Heater Width Hei
g
ht
Size mm mm
75 - 100 317 462
125 387 462
150 - 175 527 462
200 - 225 667 462
250 - 300 876 462
350 1016 462
355 & 400 1156 462
All ducting must be securely supported in such a way that there is
no undue strain. The heater should not be used to provide any sup-
port for the ductwork. If equipped with louvres, remove the louvres
and louvre frame before attaching ductwork. Attach the ductwork
to the flanges; donotattachductworktotheheater cabinet. Joints
to the heater outlet must be securely sealed to prevent air leakage
into the draughthood or burner area. Leakage can cause poor com-
bustion and/or a pilot problem and shorten heat exchanger life.

Mfg No. 144662 Rev. 2, Page 11
6.0 COMMISSIONING AND TESTING
The commissioning and testing should only be carried out by a competent person. This section should be read completely and fully under-
stood. A commissioning service is available from AMBI-RAD.
6.1 Electrical Check
After completion of the installation and before switching on the elec-
trical supply, a preliminary check must be performed by a qualified
electrician. Check the following:
((
((
(Check that all site wiring is connected in accordance with the
appropriate circuit diagram in Section 9.
((
((
(Ascertain that the correct fuse and cable size are fitted.
((
((
(Check that the earthing of the heater has been carried out by
conducting an earth continuity test. Connect a test meter, one
lead to the appliance earth point and the other lead to the main
incoming earth at the isolator. A resistance reading of 0.1 ohm
or less must be indicated. If a higher reading is obtained, check
earth connections for being clean and tight. If problem still ex-
ists, seek expert advice.
((
((
(Carry out a polarity test. Connect one lead of a suitable AC
voltmeter to earth and connect the other lead to the live supply
terminal at the heater. Turn on power to the heater and check
for proper voltage.
The same result should be obtained by connecting the test leads
from live to neutral.
Connect the voltmeter test leads to N and E. A reading of be-
tween 0-15 volts at maximum should be obtained. If these tests
do not conform to the above, there is a fault which must be
rectified before progressing further with the commission.
((
((
(Check that a suitable thermostat or control panel has been fit-
ted.
((
((
(Ensure that an isolation switch has been fitted.
((
((
(CentrifugalFan Models -- Check belt tension; see Section 6.7.5.
Check blower rotation; see Section 6.7.6. After heater is in op-
eration, verify that the amp draw does not exceed maximum
allowed on motor data plate.
6.2 Gas Connection
The whole of the gas installation, including the meter, should be
inspected, tested for soundness, and purged in accordance with
BS6891 and British Gas Document IGE/UP/1.
6.3 Suspension and Support
Check to ensure that the heater is adequately suspended or supported
and that no other parts have been fitted that are not properly sup-
ported or secured. For safe heater operation, check that the heater is
level in all directions.
WARNING: If for any reason the pilot light
goesout, allow threeminutes beforerelighting.
Locate the multifunctional control valve and identify the control
knob. While lighting the pilot, depress the control knob. Once the
pilot is established continue to depress the knob for 20 seconds and
then release slowly.
Re-attach the access panel.
Adjust the room temperature control setting to above the ambient
temperature. The main burners will light (the main burners can be
seen through the viewing port).
6.4.2 Turning "OFF" a Heater with a Permanent
Pilot
To turn off both the pilot and the main burner, rotate the knob on the
multifunctionalvalvein a clockwise direction. WAITTHREEMIN-
UTES BEFORE RELIGHTING THE HEATER.
6.4.3 Turning "ON" a Heater with Spark Ignition
The ignition spark ignites the gas creating a pilot flame. The flame
is detected by the flame rod. If a pilot flame is not detected within 50
seconds, the ignition controller locks out and must be manually re-
set. The reset button is on the heater (or a site-provided, remote
button may be fitted).
(Ensure that the electrical supply and the gas supply to the heater
are turned "ON"
(If fitted with a clock control, set to "ON".
(Adjust the room temperature control to the required operating
temperature. The heater will operate automatically.
NOTES: If heater will not "start" on initial start up, the ignition
controller may be in lockout position. Depress the reset button. Sev-
eral attempts at lighting the pilot may be required to remove the air
from the multifunctional valve.
6.4.4 Turning "OFF" a Heater with Spark Ignition
To turn "OFF" the heater for a short period, adjust the room tem-
perature control to its lowest temperature or "OFF". The fan will
continue to run to cool the heat exchanger before turning off auto-
matically.
To turn "OFF" the heater for a long period, adjust the room tempera-
ture control to its lowest temperature or "OFF". When the fan has
stopped, turn "OFF" the gas and the electricity supplies.
6.5 Heater Pipework
The soundness of the heater's pipework has been checked at the
factory. However, during shipment or installation, connections may
be loosened. Check the soundness of the pipework using a leak-
detecting fluid such as a soap and water solution. If any leaks are
found, they must be rectified immediately.
WARNING: Never use a naked flame for
checkingthe soundness ofany gas connections.
6.6 Adjustments
6.6.1 Burner Gas Adjustment
The gas pressure is set for the required heat input before the heater
leaves the factory, and normally the gas pressure will not require re-
setting. To check gas pressure, the following procedure should be
carried out.
1) Ascertain from Section 1, Technical Data (Table 3 or 4), the cor-
rect burner pressure for the heater.
2) Turn the room temperature control to its lowest setting.
3) Remove the screw from the outlet pressure test point of the gas
valve (See Figure 7, page 12). Connect a manometer to the test
point.
6.4 Lighting the Heater (Read and
understand all steps before lighting.)
The heater is fitted with either a permanent pilot which requires
lighting or an automatic spark ignition system. Determine the type
of pilot and follow the appropriate instructions.
6.4.1 Lighting a Heater with a Permanent Pilot
((
((
(Ensure that the electrical supply to the heater is turned "On"
((
((
(Set the room temperature controller to lowest setting. If a clock
control and a summer/winter switch have been fitted, ensure that
they are set to "ON" and winter.
((
((
(Turn on the main gas supply to the heater.
Remove the access panel on the control side of the heater. (While
servicing the heater, the side access panel is designed to "hang"
from the bottom panel of the heater. Place the extended top edge of
the side panel over the lip on the bottom panel of the heater. The
side panel will "hang" suspended from the bottom panel until ready
to be re-installed on the heater.)
With the panel removed, the pilot lighting hole is in view (on the
right side of the burner rack).

Form WA/010, Page 12
6.0 COMMISSIONING AND TESTING (cont'd)
6.6.1 Burner Gas Adjustment (cont'd)
Outlet
Pressure Test
Port
Figure 7 - Multifunctional Control Valves
(NOTE: When measuring gas pressure, do not
remove screw. Loosen enough to allow gas
pressure to register. )
Multifunctional Control
Valve on a Heater with a
Standard Permanent Pilot
Multifunctional Control Valve on a Heater with Optional Spark Ignition
6.6.1 Burner Gas Adjustment (cont'd)
4) Adjust the room temperature control to a setting above ambient
temperature.
5) Observe the gas pressure on the manometer and compare to re-
quired burner pressure.
6) If necessary, adjust the burner gas pressure. Remove the cover
screws. Turn the regulator screw anti-clockwise to decrease the
pressure or clockwise to increase the pressure.
7) Set the room temperature control to lowest setting to turn off the
main burners. Replace the pressure test point screw and cover
screw (if removed) and with the main burner turned on, test for
gas soundness using a leak-detection fluid such as a soap and
water solution.
Reset temperature control to required operating temperature.
6.6.2 Pilot Flame Adjustment - Permanent
Pilot
The pilot regulating screw is contained in the multifunctional con-
trol valve. The pilot regulating screw is factory set for the maximum
pilot rate. If the G20 natural gas inlet pressure to the heater exceeds
25 mbar (10 inches W.G.), the pilot rate should be reduced.
Pilot Flame Adjustment Instructions
1) Remove the cover screw (see Figure 7).
2) To adjust the pilot flame, turn the adjusting screw clockwise to
reduce the flow.
3) Replace the cover screw after pilot adjustment is completed.
Control Knob -
depress while
lighting pilot
Pressure
Regulator
Cover Screw
Pilot
Regulating
Screw
Inlet Pressure
Test Port
Top View
Inlet Pressure
Test Port Outlet Pressure
Test Port
Pressure Regulator
Cover Screw
Inlet
Pressure
Test Port
Outlet
Pressure
Test Port
Side View
Gas Flow

Mfg No. 144662 Rev. 2, Page 13
6.7 Air Distribution System
6.7.1 General Requirements
The system should be checked to ensure that the installation work
has been carried out in accordance with the design requirements.
6.7.2 Free Blowing Heaters
Adjustthedischarge louvres toprovideasatisfactory spread of heated
air. Direct the heated air to the floor avoiding direct draught on per-
sonnel who may be working nearby.
CAUTION: To avoid getting burned, adjust louvres prior
to heater operation. If louvres need re-adjusting after
startup, wear protective gloves.
The free blowing heater is equipped with a motor with thermal over-
load protection of the automatic reset type. Should the motor refuse
to run, it may be because of improper current characteristics. Make
certain that the correct voltage is available at the motor.
6.7.3 Ducted Heaters - Model TB or Model TE
Heaters with a centrifugal blower for air delivery are limited to a
maximum external pressure of 500 Pa (2.0 inches W.G.) and a tem-
perature rise of 42oC.
Most motors are equipped with thermal overload protection of the
automatic reset type. If a motor is not equipped with thermal over-
load protection, the unit will be and the starter must be manually
reset.
After the installation is complete including all ductwork, check the
amp draw of the motor with an amp meter to verify that the motor
amp rating on the motor data plate is not being exceeded. Amps may
be adjusted downward by reducing blower speed or by increasing
the duct system static pressure. The temperature rise must be within
the range specified on the unit rating plate.
6.7.4 Adjusting Centrifugal Fan (Blower) Speed
The blower speed may be adjusted to achieve the desired outlet tem-
perature, as long as the adjustment is within the temperature rise and
the static pressure limits shown on the heater rating plate. Motors
are factory set between maximum and minimum blower speeds.
If the duct resistance is low, the blower may deliver too high an air
volume. If the resistance is very low, the blower may deliver excess
air to overload the motor, causing the overload protector to cycle the
motor. Reducing the blower speed will correct these conditions. If
ductwork is added to an installation, it may be necessary to increase
the blower speed. Decreasing blower speed will increase outlet tem-
perature; increasing blower speed will decrease outlet temperature.
The belt drive on these units is equipped with an adjustable pulley
which permits adjustment of the blower speed. Follow these instruc-
tions to adjust the blower speed.
1. Turn off the gas and the electric power.
2. Loosen belt tension and remove the belt.
3. Loosen the set screw on the side of the pulley away from the
motor.
4. To increase the blower speed, decreasing outlet temperature,
turn the adjustable half of the pulley inward. To decrease the
blower speed, increasing the outlet temperature, turn the ad-
justable half of the pulley outward. One turn of the pulley will
change the speed 8-10%.
5. Tighten the set screw on the flat portion of the pulley shaft.
6. Replace the belt and adjust the belt tension. Adjust tension by
turning the adjusting screw on the motor base until the belt can
be depressed 19 mm. (See Figure 13, page 16.) Re-tighten the
lock nut on the adjusting screw.
7. Turn on the gas and electric. Light the heater following the in-
structions on the lighting instruction plate.
8. Check the motor amps with an amp meter. The maximum motor
amp rating on the motor nameplate must not be exceeded.
When service is complete, carry out commissioning procedure, Sec-
tion 6.0-6.8.
6.7.5 Check Belt Tension
Check the belt for proper tension. Proper belt tension is important to
the long life of the belt and motor. A loose belt will cause wear and
slippage. Too much tension will cause excessive motor and blower
bearing wear. Adjust the belt tension by turning the adjusting screw
on the motor base until the belt can be depressed 19 mm. (See Fig-
ure 13, page 16.) After correct tension is achieved, re-tighten the
locknut on the adjusting screw.
6.7.6 Blower Rotation
Each blower housing is marked for proper rotation. Rotation may be
changed on single-phase motors by re-wiring in the motor terminal
box.Three-phasemotors may be reversed by interchanging two wires
on the 3-phase supply connections.
6.8 Heater Controls
6.8.1 Standard Heater Controls
Check heater operation after all adjustments have been carried out.
Set the room temperature control to above ambient temperature. The
main burner will light. Within approximately 30 seconds, the fan
thermostat control will sense a rise in the temperature of the heat
exchanger and energize the fan or blower motor. (The fan control
has a fixed setting and cannot be adjusted.)
Continue to operate the heater for several minutes to ensure the limit
switch does not activate. The limit switch is a manually reset switch
which must be cooled to room temperature before being reset. The
reset button is accessible by opening the heater control panel. If for
any reason, the limit switch trips, the cause must be determined. See
Fault Finding Chart, Section 10.3.
Turn the room temperature control to its lowest setting. The main
burners should extinguish while the fan or blower continues to cool
the heat exchanger. When the heat exchanger is sufficiently cooled
(usually within five minutes), the fan control will de-energize the
fan or blower motor.
The circuit diagram on the heater indicates the type of gas control.
6.8.2 Heater with Optional Two-Stage Gas
Control
Checks and operation sequence are the same as in Section 6.8.1,
except that the heater is controlled by a two-stage temperature con-
troller and a two-stage valve (50% and 100%). Depending on the
temperature control setting, the gas valve fires the burner at either
50% or 100%.
6.8.3 Heater Controls with Optional Electronic
Modulation Gas Control
Checks and operation sequence are the same as in Section 6.8.1,
except that the gas valve is electrically controlled to modulate be-
tween 50% to 100% firing rate depending on the temperature re-
quirement.
6.9 Handing Over
Uponthesatisfactorycompletionofcommissioningandtesting,hand
the instructions to the user or purchaser. Advise the user/purchaser
how to safely use and operate the heater, including all associated
equipment and controls. Ensure that the user/purchaser understands
how to start the heater and how to turn it off.
Suggest that the instructions be placed close to the heater for future
reference. Instruct the user/purchaser not to place the instructions
adjacent to a hot surface or in a place where they may restrict air
flow.
Advise the user/purchaser that for safe and efficient operation, the
heater must be serviced at least annually. A complete after sales ser-
vice is available from AMBI-RAD.

Form WA/010, Page 14
WARNING:Onlycompetentandqualifiedengineersshouldcarryoutservicingandfaultfinding
on this equipment. Complete after-sale service is available from AMBI-RAD.
Before maintenance is carried out, ensure that both gas and electrical supplies are turned off
and the appliance is cold.
7.0 SERVICING INSTRUCTIONS
This heater will operate with a minimum of maintenance. To ensure long life, satisfactory performance and continued safety, a
heater that is operated under normal conditions should be inspected and cleaned annually. Heaters that are operated in areas
where an unusual amount of dust or impurities are present in the air, require more frequent maintenance.
7.1 Servicing Requirements/Procedure
The following procedures should be carried out at least annually:
1. Remove the Burner Assembly as in Section 8.1.
a) Check the condition of the pilot burner and clean off any
deposits which may have formed. Clean the inside of the
burner hood with an emery cloth. Clean the pilot injector
withsolvent and compressedair. CAUTION:Wearingeye
protection is recommended.
Check the condition of the thermocouple or flame rod and
clean with an emery cloth. Remove all deposits. If signs of
erosion are visible, renew the thermocouple or flame rod.
On pilots with a flame rod (spark ignition), check the spark
gap (2.5 mm).
b) Clean any deposits from the main burner, paying particu-
lar attention to lint or fluff, etc., which may have formed
around the injectors in the venturi of the burner. Clean us-
ing compressed air and a soft brush. CAUTION: Wear-
ing eye protection is recommended.
c) Clean any deposits from the burner tray.
2.The heat exchanger should remain clean unless some prob-
lem has developed with combustion. Examine the heat ex-
changer internally and externally for any sign of deterio-
ration.
3. Model TA — The fan blade, fan guard and motor should
be cleaned to remove any buildup of dust, fluff, etc.
Model TB — The blower, belt guard, inlet guard and mo-
tor should be cleaned to remove any buildup of dust or
fluff. The blower belt should be checked for tension and
wear. Worn belts should be replaced (See Section 8.6).
Model TE — The blower and motor should be cleaned to
removeany buildup of dust or fluff.The blowerbelt should
be checked for tension and wear. Worn belts should be
replaced (See Section 8.6).
4. Ensure that any purpose provided air vents for ventilation
and combustion are free from obstruction.
5. The flue system should be checked for soundness. Reseal/
replace any parts that do not appear sound.
6. Check the wiring for any signs of damage. Replace wiring
with an equivalent specification.
7. Check operation of the fan control.
8.When service is complete, carry out commissioning proce-
dure, Section 6.0-6.8.
Figure 8 - Check Spark Gap on Optional
Spark Pilot Assembly

Mfg No. 144662 Rev. 2, Page 15
8.1 Main Burner Removal
Instructions for Burner rack Removal
1. Remove the control access panel from the heater. (The side panel is
designed to "hang" from the bottom panel of the heater. Place the edge
over the lip on the side of the bottom panel of the heater, carefully
allowing the side panel to "hang".)
2. If equipped with spark ignition, open the electrical box cover and dis-
connect the ignitor lead from the ignition controller. Disconnect the
flame sensor lead (wire from the ignition controller to the probe) from
the auxiliary flame probe.
3. Mark and disconnect electric valve leads.
4. Uncouple the union in the gas supply line upstream from the valve.
5. Remove the two screws holding the bottom of the burner rack assem-
bly. Slide the "drawer-type" burner rack out of the heater.
Instructions to Re-Assemble
1. Reverse the Steps to disassemble and remove the burner
rack.
2. When lighting, always follow the lighting instructions on
the heater. After any service work, the heater must be fully
commissioned. See Section 6.0-6.8.
Instructions to remove the individual burners from the burner rack
assembly :
1. With the burner assembly upside down, remove the screws (located at
the rear) that secure the retaining bracket.
2. Lift the front of the burner upwards slightly and pull it back, removing
the individual burner (a slight tap with a wooden mallet is sufficient to
dislodge it).
3. Clean individual burners using air pressure or soft brush Use an air
nozzle to blow out scale and dust accumulation from the burner ports.
CAUTION: Wearing eye protection is recommended. Alternately
blow through burner ports and venturi. Use fine wire to dislodge any
stubborn particles. Do not use anything that might change the port
size.
Figure 10 - Individual Burner Removed from
the Burner Rack
NOTE: Use only factory-authorised replacement
parts. Heaters supplied after 1/1/96 must use
certificated spares to comply with legislation.
A complete spares service is available from AMBI-RAD.
8.2 Pilot Burner Injector
1. If connected, disconnect the pilot tubing from the pilot
burner.
2. Fit a new pilot burner injector.
3. Re-assemble in reverse order.
8.3 Pilot Burner Assembly
1. To remove the pilot assembly, remove its two fixing screws.
2. Refit the new pilot burner by re-assembling in reverse or-
der.
3. Check relationship of the pilot burner with the adjacent
main burner. Refer to Figures 11 and 12.
Figure 11 - Relationship of Permanent Pilot
Assembly and Main Burner
8.0 REMOVAL AND REPLACEMENT OF PARTS
WARNING:Tocomplywith legislation, onlycertificatedsparesmay befittedtoheaterssupplied
after 1/1/96. A full spares service is provided by AMBI-RAD. Only a competent and qualified
engineer should carry out servicing on this equipment. Before maintenance is carried out,
ensure that both gas and electrical supplies are turned off and the appliance is cold.
After maintenance work, the heater MUST be fully commissioned (See Section 6).
Valve
Figure 9 - Control Side with Access Panel
Removed for Removal of Burner Rack
Burner Rack
Union
Electrical Box
The access panel will "hang"
over the edge of the bottom
panel.
Remove Burner Rack
Screws (one on each side)

Form WA/010, Page 16
8.5 Main Burner Injectors
1. Remove the burner rack (See Paragraph 8.1).
2. Remove the manifold bracket screws and manifold.
3. Unscrew the main burner injectors.
4. Re-fit new injectors.
5. Re-assemble in reverse order.
8.6 Blower Motor and Belt
8.6.1 Belt Tension
Check belt tension. Belt should depress approximately 19 mm. See
Figure 13.
Adjust belt tension by means of the adjusting screw on the motor
mounting plate.
When belt is adjusted properly, tighten the lock on the adjusting
screw.
8.6.2 Blower Motor
Check motor amps with an ammeter. The maximum motor amp rat-
ing on the motor badge must not be exceeded.
CAUTION: A ducting system having excessive
static pressure may cause the limit control to
actuate.
Figure 13 - Belt
Tension
8.0 REMOVAL AND REPLACEMENT OF PARTS (cont'd)
8.4 Optional Spark Pilot Ignition System
The ignition controller of the intermittent electronic ignition pilot
system is located in the electrical box. There are no field-replace-
able components in the ignition controller. Check the lead wires for
insulation deterioration and good connections.
Proper operation of the electronic spark ignition system requires a
minimum flame signal of 0.7 micro amps as measured by a micro
amp meter.
CAUTION:Due to high voltage on pilot spark wire
and pilot electrode, do not touch when energized.
Figure 12 - Relationship of Spark Pilot Assembly and
Main Burner
8.3 Pilot Burner Assembly (cont'd)
8.8 Multifunctional Control Valve
1. Ensure the electrical supply is isolated.
2. Remove the pilot supply tube and the spark tension lead.
3. Remove the terminal cover and disconnect the electricity con-
nections.
4. Disconnect the union between the multifunctional control valve
and the gas service cock. Remove the valve.
5. Re-fit the replacement valve making all the required connections.
If the connection includes an O-ring, fit a new O-ring.
6. Carry out a complete commissioning procedure. Refer to Sec-
tions 6.0 to 6.8.
8.9 Limit and High Temperature Limit
Controls
The heater is fitted with a limit control and a high temperature limit
control.
The limit control switch fitted on the side of the heater (Refer to
Figures 15 and 16) has a sensor capillary tube that stretches two
times across the heat exchanger discharge opening. The switch is a
manual reset type which interrupts the circuit to the heater operating
controls. Before replacing, be certain that the limit control sensor
capillary tube has cooled sufficiently. If it has been determined that
the limit control needs replacing, use only a factory-authorised re-
placement.
The high temperature limit control is a redundant safety device cali-
brated to open at a much higher temperature than the limit control.
The high temperature limit control is a manual reset type. A high
temperaturelimitcontrol interruption indicates a major failure caused
by a malfunction of the primary safety controls or miswiring. The
cause must be determined and corrected; both the fan control and
the limit control must be replaced; and the entire heater must be
inspected for damage to wiring and controls.
Figure 14 - Correct Spacing of
the Fan Blade on the Motor
Shaft
Heater Size "A" -- Hub to Motor Spacing
100 65 mm
125 52 mm
150, 175, 200, 225 65 mm
250, 300 52 mm
350, 355, 400 65 mm
8.7 Replacement of Fan Motor and/or Blade
Follow these instructions for removal and replacement of fan motor
and/or fan blade.
1. Turn off the gas supply.
2. Disconnect the electrical power to the heater.
3. Disconnect the fan motor wires and push out the cable retaining
gland.
4. To remove the subassembly including the fan motor, the blades,
and the fan guard, remove the screws that attach the fan guard to
the heater.
5. Either the fan motor, fan blade or both may now be replaced.
Space the fan blade on the shaft as shown in Figure 14.
6. Re-assemble in reverse order.
"A" Fan Hub
Motor

Mfg No. 144662 Rev. 2, Page 17
Figure 16 - Non-Control Side of the Heater with
Cabinet Panel Removed showing the Limit Control
Capillary Tubing
Figure 15 - The "Lower
Temperature"Limit
Control Reset Switch is
on the Control Side of
the Heater. This limit
switch has a capillary
tubing sensor that
stretches two times
across the heat
exchanger discharge.
When activated, the
switch "turns off" the
gas controls.
8.9.1 Instructions for Replacement of Limit
Switch Control
1. Remove the heater side panel on the non-control side of the heater
and the access panel on the control side of the heater. The limit
switch reset button is visible; see Figure 15.
3. Disconnect the limit switch wires from the gas valve.
4. The one-piece capillary tube extends twice across the outlet of
the heat exchanger. To replace: a) from the non-control side of
the heater (See Figure 16), pull the upper portion of the "copper-
coloured" capillary tube out of stainless steel tube. b) From the
control side, withdraw the full length of capillary tubing.
5. Remove the limit switch control from the bracket by removing
the two retaining screws.
6. Replace the limit control switch and re-assemble in reverse or-
der, ensuring that the capillary tube extends two times across the
full width of the heat exchanger.
7. Carry out a complete commissioning procedure. Refer to Sec-
tion 6.0 to 6.8.
8.9.2 High Temperature Limit Switch Location
The high temperature limit control is located in the electrical box
abovethe fan temperature control. Ifthehigh temperature limit switch
activates, the primary limit switch and fan control must be replaced.
The high limit switch may be reset.
When Removing Tubing:
On this side, pull the "copper
coloured" capillary tubing from the
upper row of stainless steel tubing
so that the full length can be pulled
through the lower row of tubing and
removed from the control side of the
heater.
8.10 Fan Temperature Control
The fan temperature control senses the temperature of the heat ex-
changer. The fan temperature control has a fixed setting and may not
be site adjusted. If it is determined that the fan temperature control
needs replacing, use only a factory-authorised replacement part. (See
Section 8.0.)
The fan control is located in the electrical box.
As with all service procedures, carryout a complete commissioning
procedure after replacement of the fan control. Refer to Sections 6.0
to 6.8.
When Installing New Tubing:
Be sure tubing extends twice across
the full width of the heat exchanger.
"Coil" excess capillary tubing (on
non-control side) as illustrated.
(1) To remove, pull
out here.
(2) Uncoil and pull
through to the other
side.

Form WA/010, Page 18
9.0 CIRCUIT DIAGRAMS
9.1 Site Wiring
9.1.1 Site Wiring for Heater with Standard Permanent Pilot
and Single Stage Control
9.1.2 Site Wiring for Heater with Optional Spark Ignition
and Standard Single Stage Control

Mfg No. 144662 Rev. 2, Page 19
9.1.4 Site Wiring for a Heater with Optional Spark Ignition
and Optional Electronic Modulation Control
9.1.3 Site Wiring for a Heater with Optional Spark
Ignition and Optional Two-Stage Control

Form WA/010, Page 20
9.0 CIRCUIT DIAGRAMS (cont'd)
9.2 Circuit Diagram -- Standard Heater with an Axial Fan(s) for Air Delivery
9.2.1 Model TA with Permanent Pilot, Sizes 100-225 (W.D. #142213)