Ambirad UF25-2 User manual

Mfg No. 135847, Page 1
InstallationFormWA/004/0399
APPLIES TO: Installation, Commissioning, and Service
Table of Contents
AMBI-RAD
Model UF Series 2
Gas-Fired Unit Heaters
Read these instructions thoroughly before
commencing installation.
0063
1.2 Warranty
Warranty is void if. . .
a. Model UF heater is installed in atmospheres containing flam-
mable vapours or atmospheres containing chlorinated or ha-
logenated hydrocarbons or atmospheres containing any sili-
cone, aluminum oxide, etc. that adheres to spark ignition fame
sensing probes.
b. The installation is not in accordance with these instructions.
c. Model UF, axial fan-type unit heater , is connected to a duct
system or fitted with a non-factory authorised air distribu-
tion device.
d. Fitted in the printing industry where fine starch or sugar
dusts are used.
1.0INTRODUCTION
1.1 Basic Information
The instructions in this manual apply to Model UF Series 2 gas-fired
naturaldraughtairheaters. ModelUF heatershave anaxial fanfor air
delivery.
These heaters are designed for overhead suspension and are suitable
for indoor installation only.
A permanent electricity supply of 230 volts, 50 Hz, single phase is
required for all UF Models.
Models UF heaters are Appliance Type B11 , Category I2H3P , self-
contained warm air units supplied ready for installation on site.
They are fitted with a permanent pilot. A thermoelectric flame su-
pervision device monitors the pilot flame to prevent an explosive
condition occurring.
When the external controls call for heat, the multifunctional control
valve opens, the main burner ignites and supplies heat to the heat
exchanger. After approximately 45 seconds the air delivery fan will
start to run and supply warm air.
When the required room temperature is reached, the main burner will
shut down leaving the fan running to cool down the heat exchanger.
When cool enough, the fan thermostat will turn off the fan.
PLEASE READ THESE INSTRUCTIONS
THOROUGHLY BEFORE COMMENCING
WORK.
WARNING:Improperinstallation,adjustment,
alteration, service or maintenance can cause
injury or property damage. All work must be
carried out by competent persons, i.e. a
registered CORGI installer.
HAZARDINTENSITYLEVELS
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
beusedinan emergency andshouldnotbeused
forclosingdownthemainburner, as it switches
offthefanprematurelyandmaydamagetheheat
exchanger, invalidatingthewarranty.
5.0 Air Distribution System
5.1 Horizontal Louvres and Outlet Nozzle
5.1.1 Instructions to Fit Outlet Nozzle
5.2 Vertical Louvres (Option)
5.3 Downturn Air Nozzles (Option)
6.0 Commissioning and Testing
6.1 Electrical Check
6.2 Gas Connection
6.3 Suspension
6.4 Lighting the Heater
6.5 Heater Pipework
6.6 Adjustments - Main Burner and Pilot
6.7 Draught Diverter
6.8 Air Distribution System
6.9 Heater Controls
6.10 Handing Over
7.0 Servicing Instructions
7.1 Procedure
8.0 Removal and Replacement of Parts
8.1 Main Burner
8.2 Thermocouple
8.3 Pilot Burner Injector
8.4 Pilot Burner Assembly
8.5 Main Burner Injectors
8.6 Fan Motor/Blade
8.7 Multifunctional Control Valve
8.8 Limit Control
8.9 Fan Temperature Control
9.0 Circuit Diagrams
10.0 Fault Finding Charts
11.0 Short List of Parts
12.0 Exploded Diagrams
12.1 Cabinet Parts
12.2 Heat Exchanger/Burner
13.0 Supplementary Information
1.0 Introduction
1.1 Basic Information
1.2 Warranty
2.0 Technical Data
2.1 Specifications
2.2 Burner Injector Size and Pressure
2.3 Dimensions
3.0 General Requirements
3.1 Related Documents
3.2 Heater Locations
3.3 Flue System
3.4 Air Supply
3.5 Gas Supply
3.6 Air Distribution System
3.7 Electrical Supply
4.0 Installation
4.1 Uncrating and Preparation
4.2 Suspending the Heater
4.3 Fitting the Flue System
4.4 Gas Connection
4.5 Electrical Connections
4.6 Control Panel Siting

Form WA004, Page 2
2.0 TECHNICAL DATA - Model UF Series 2
2.1 Specifications
2.2A Burner Injector Size and Pressure -
Natural Gas
Figure1-ModelUF
Series 2
Table 1 - UF Specifications
Model Heat Input Heat Output Maximum Gas Rate!
!!
!Air Volume Running Power Fuse
kw BTUH kw BTUH m3/h ft3/h m3/h ft3/min Amps!
!!
!Consumption"
""
"Size
UF25-2 7.3 25,000 5.9 20,000 0.69 24.3 573 337 0.45 100 watts 1 Amp
UF50-2 14.6 50,000 11.7 40,000 1.38 48.5 1143 673 0.45 100 watts 1 Amp
UF75-2 22.0 75,000 17.6 60,000 2.06 72.8 1888 1111 0.50 110 watts 1 Amp
UF100-2 29.3 100,000 23.4 80,000 2.75 97.1 2516 1481 1.00 220 watts 2 Amps
UF125-2 36.6 125,000 29.3 100,000 3.44 121.4 3272 1926 1.05 240 watts 2 Amps
UF165-2 48.3 165,000 38.7 132,000 4.54 160.2 4152 2444 1.10 270 watts 2 Amps
UF200-2 58.6 200,000 46.9 160,000 5.50 194.2 5034 2963 1.20 290 watts 5 Amps
UF250-2 73.2 250,000 58.6 200,000 6.87 242.7 6293 3704 1.80 350 watts 5 Amps
UF300-2 87.9 300,000 70.3 240,000 8.25 291.3 7550 4444 2.00 450 watts 5 Amps
UF400-2 117.2 400,000 93.8 320,000 11.00 388.3 10068 5926 2.50 580 watts 5 Amps
!Gas flow rate is based on a gas with a C.V. of 39.9 MJ/m3 (1030 BTUH) and includes a pilot flow
rate of 264 watts (900 BTUH).
"Based on normal operation at 230 volts and 50 hertz.
2.2B Burner Injector Size and Pressure -
Propane Gas
Model Qty Injector Size Injector Burner Pressure
mm Marking m bar
UF25-2 2 1.70 51 8.8
UF50-2 3 1.99 47 8.8
UF75-2 4 2.08 45 8.8
UF100-2 5 2.18 44 8.8
UF125-2 6 2.18 44 8.8
UF165-2 5 2.79 35 9.0
UF200-2 6 2.79 35 9.0
UF250-2 8 2.79 35 9.0
UF300-2 9 2.79 35 9.0
UF400-2 12 2.79 35 9.0
Table 2A - Injector Size and Burner Pressure Model Qty Injector Size Injector Burner Pressure
mm Marking m bar
UF25-2 21.02 60 25
UF50-2 3 1.20 1.2MM 25
UF75-2 4 1.30 1.3MM 25
UF100-2 51.32 55 25
UF125-2 61.32 55 25
UF165-2 5 1.65 1.65MM 25
UF200-2 6 1.65 1.65MM 25
UF250-2 8 1.65 1.65MM 25
UF300-2 9 1.65 1.65MM 25
UF400-2 12 1.65 1.65MM 25
Table 2B - Injector Size and Burner Pressure

Mfg No. 135847, Page 3
Figure2
2.3 DIMENSIONS - Model UF Series 2
Table3
Model A B C D E (Hanger) F
mm mm mm mm mm mm
UF25-2 737 344 687 148 367 689
UF50-2 737 344 687 148 367 689
UF75-2 737 395 687 148 367 689
UF100-2 737 446 794 148 367 689
UF125-2 737 592 794 148 367 689
UF165-2 990 516 911 124 495 802
UF200-2 990 592 911 124 495 802
UF250-2 990 732 937 124 495 802
UF300-2 990 732 937 124 495 802
UF400-2 990 941 937 124 495 802
Model G H (Internal) J K M Approx. Net Wt
mm mm BSP inches mm mm kg
UF25-2 451 102 3/4 261 213 33
UF50-2 451 102 3/4 261 213 36
UF75-2 451 127 3/4 267 213 40
UF100-2 451 153 3/4 328 149 44
UF125-2 436 178 3/4 366 149 58
UF165-2 543 203 3/4 363 149 68
UF200-2 543 203 3/4 366 149 77
UF250-2 543 254 3/4 314 187 93
UF300-2 543 254 3/4 314 225 100
UF400-2 543 254 3/4 330 225 125

Form WA004, Page 4
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 main-
tained for best results.
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 to be heated, the air should
be discharged along exposed walls. In large areas, unit should be
locatedto dischargeair alongexposed wallswith extraunits provided
to discharge air in toward the centre of the area. At those points
where infiltration of cold air is excessive, such as at entrance doors
and loading doors, it is desirable to locate the unit so it will discharge
directly toward the source of cold air from a distance of 4.5 to 6.0
metres.
3.0 GENERAL REQUIREMENTS
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 requirements 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.
THERELEVANTREGULATIONSARE...
GASSAFETY(INSTALLATIONS&USE)(Amendment)REGU-
LATIONS 1990
THEHEALTHANDSAFETY AT WORK,ETC. ACTS
••
••
•BS6230 1991 SPECIFICATION FOR THE INSTALLATION
OF GAS FIRED FORCED CONVECTION AIR HEATERS
FOR COMMERCIAL AND INDUSTRIAL SPACE HEAT-
ING OF RATED INPUT EXCEEDING 60 KW.
••
••
•BS5588 PART 1 (SECTION 1) 1990; PART 2 1985 AND
1990; AND PART 3 1983 AND 1989
••
••
•BS5440 PART 2 1989 FLUES AND AIR SUPPLY FOR GAS
APPLIANCES NOT EXCEEDING 60 KW
••
••
•BS6891 1988 LOW PRESSURE INSTALLATION PIPES
BRITISHGAS PUBLICATIONS
IGE/UP/1 PURGING PROCEDURES FOR NON-DOMESTIC
INSTALLATIONS and SOUNDNESS TESTING PROCE-
DURES FOR INDUSTRIAL INSTALLATIONS.
I.E.E. REGULATIONS FOR ELECTRICAL INSTALLATIONS
AND THE REQUIREMENTS OF THE FOLLOWING...THE
LOCALREGION OF BRITISHGASPlc
WARNING: Air heaters should not be installed
in corrosive atmospheres, i.e., near plating or
degreasing plants or in areas where there is a
firerisk.ConsultBS6230forfurtherinformation
onhazardousareas.
3.2 Heater Location
The location chosen for the heater must permit the provision of a
satisfactory flue system and an adequate air supply. The location
must also provide space for servicing and air circulation around the
unit.
Table 4 - RequiredClearances (mm)
Sizes Top Flue Sides Bottom Rear Front
25 -
125 152 152 460 610 610 1830
165 -
250 152 152 460 610 610 2440
300 -
400 152 152 460 610 610 3050
For service purposes, rear must have 610 mm clearance. When sup-
plied with optional downturn nozzle, bottom clearance is 1.0 m.
The location should be free of draughts.
WARNING: Avoidinstalling a unitinan extremely
draughty area. Extreme draughts can shorten the
life of the heat exchanger and/or cause safety
problems.
Refer to Table 5 for recommended mounting height for UF Models.
3.3 Flue System
Each heater must be fitted with an adequately sized flue (See Table
6). Stainless steel flue pipe is recommended.
WARNING: The flue must be installed in
accordancewithBS5440Part 11990 forallmodels
up to and including Size 200 or BS6230 1991 for
all Models Size 250 and over.
Failure to provide proper flueing could result in
death,seriousinjuryand/orpropertydamage.The
unit must be installed with a flue to the outside of
thebuilding.Safeoperationofanynaturaldraught
gas burning equipment 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 flue pipe
is recommended. When double wall flue pipe is used, it should be a
type complying with British Standards. Double wall flue pipe re-
quires the use of a special flue socket adapter. Where condensation is
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 material, not less than 19 mm diameter.
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 sepa-
rated from the sleeve by at least 25 mm air gap. The temperature of
any combustible material near the flue or heater must not exceed 65o
C when the heater is in operation. The flue must also be at least 50
mm from any other combustible material.
The joint between the female flue socket of the heater and the flue
must be sealed. If twin wall flue piping is used, the appropriate
adapter must be fitted.
The joints between the flue and the roof must be made good to
prevent water ingress.
Table 6 - Flue Diameter and Minimum Hei
g
ht
Size 25 50 75 100 125 165 200 250 300 400
Flue Pipe
Diameter mm 100 100 125 150 175 200 200 250 250 250
Min. Height
of Flue M 1.5 1.5 1.5 1.5 2.0 2.0 2.0 2.0 2.0 2.0
Table 5 - Recommended Mounting Heights
UF Models 25 - 125 165 - 250 300 - 400
Mounting Height 2.5 - 3 m 2.5 - 3.5 m 3 - 5 m

Mfg No. 135847, Page 5
3.4 Air Supply
It is important to ensure that there is adequate air supply at all times
for both combustion and heating requirements. Modern construction
methods involve the greater use of insulation, improved vapour bar-
riers and weather-stripping, with the result that buildings generally
are much tighter structurally than they have been in the past. Com-
bustion air supply for gas-fired equipment can be affected by these
construction conditions because infiltration that would have existed
in the past may not be adequate. Extensive use of extract fans aggra-
vates the situation. It is important to ensure that there is an adequate
air supply at all times. The use of doors or windows which may be
closed is not allowed for the provision of ventilation.
Always ensure that adequate combustion air is provided in compli-
ancewith BS5440and/or BS6320 dependenton heat outputof unit(s).
3.5 Gas Supply
Model UF heaters are designed to operate on G20 natural gas. Model
UF heater may be used on propane gas only if fitted with the correct
propane orifices. Consult the data plate for gas type and for mini-
mum and maximum supply pressures. A normal natural gas supply
pressure of 20 mbar is recommended. Minimum inlet pressure for
propane gas is 27.5 mbar; maximum inlet pressure is 35 mbar.
The natural gas meter and service must be checked by the gas sup-
plier.
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
documents IGE/UP/1.
3.6 Air Distribution System
Recommendations for the air distribution system are given in the
document entitled “Standards of Installation for Gas Fired Industrial
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 machin-
ery, etc.” Various outlet configurations are available as optional ex-
tras to modify the air throw pattern to suit particular site conditions.
(See Section 5.)
If the heater is to be installed in a restricted space, adequate provi-
sion must be made for return air to avoid any interference with the
operation of the flue by the air circulation fan.
3.7 Electrical Supply
Wiring external to the air heater must be installed in accordance with
the I.E.E. Regulations and be carried out by a qualified electrician.
A constant 240V 50 Hz single phase supply is required for all UF
Models. All heaters and controls must be correctly earthed. An iso-
lator 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 installa-
tion, each heater must be provided with a separate isolator.
The final connection to the heater should be to the appliance terminal
block (See Fig 3). Cable size should be 1.0 mm. See Section 2, Tech-
nical Data, for required fuse size.
The length of the conductors 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
cordanchorage.
WithCoverinPlace
4.0INSTALLATION
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 electrical charac-
teristics of the heater to be sure that they are compatible with the gas
and electric supplies at the installation site. Read this booklet and
become familiar with the installation requirements of your particular
heater. Before beginning, make preparations for necessary supplies,
tools, and manpower.
Check to see if there are any site-installed options that need to be
assembled on the heater prior to installation. Each of the option
packages includes a list of components and complete, step-by-step
instructions. For a brief explanation of frequently specified site-
installed options, see Section 5. After becoming familiar with the
instructions, assemble and install the options that are required for
your heater.
Do not remove the wooden pallet until after the unit has been
suspended, otherwise the bottom access panel could be dam-
aged.
4.2 Suspending the Heater
Model UF heaters are designed to take combustion air via slots in the
base panel. The units are therefore not suitable for base mounting
and must be suspended from the roof structure or from suitable wall
brackets. Before suspending the heater, check the supporting struc-
ture to be used to verify that it has sufficient load-carrying capacity
to support the weight of the unit and the ancillary equipment. (See
Table 7.)
Each heater is equipped with four suspension brackets that are
threaded to receive a M10 x 1.5 eyebolt or threaded rod. See Figure
4 for proper eyebolt or threaded rod attachment.
Material used to support the heater should be corrosion resistant
and of sufficient strength. The gas supply pipe and electrical con-
nections should not support any of the weight of the heater.
WARNING: Suspend the heater only from the
threadedhangerbrackets.Do notsuspendfrom
the heater side panel.
WithCover
Removed
Figure 3 - Site Wiring Terminal Block
Table 7 - Net Weight of Heaters
Size 25 50 75 100 125 165 200 250 300 400
kg 33 36 40 44 58 68 77 93 100 125

Form WA004, Page 6
Figure4 - Suspension
4.2 Suspending the Heater (cont'd)
Where the location of the air heater is such that it might suffer exter-
nal mechanical damage, i.e., from overhead cranes, fork lift trucks, it
must be suitably protected.
When the heater is being lifted for suspension, the bottom must be
protected. Do not remove the heater from the wooden pallet before
suspension. If the bottom is not supported, the bottom access panel
couldbe damaged.
WARNING: Units must be level for proper
operation.Donot placeoraddadditionalweight
tothesuspendedunit.
4.3 Fitting the Flue System
The flue pipe system attaches directly to the flue socket provided on
the top of 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 a British Gas Plc
approved flue terminal.
4.4 Gas Connection
To facilitate servicing, the heater must be fitted with an approved
service gas cock and union or union cock.
Heaters suspended by flexible support material or drop rods must 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 con-
nectiontobalanceheaterorsupportanyweight
of the heater.
4.5 Electrical Connections
All electrical connections should be made in the site terminal box
(refer to Figure 3). Screw-type terminals are provided. Connections
should be in accordance with terminal markings inside the site termi-
nal box 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.
5.0AIRDISTRIBUTION
SYSTEMS AND OPTIONAL
COMPONENTS
5.1 Horizontal Louvres and Outlet Nozzle
WARNING: Model UF400 must be fitted with
anoutletnozzle(canopy).
All sizes of Model UF heaters are factory supplied with adjustable
horizontal louvres. The outlet nozzle required on Size 400 heaters
requires site fitting. Follow the instructions in Section 5.1.1 or 5.3.
Horizontal louvres may be adjusted from 10 to 55 degrees to direct
the airflow down to the floor. IMPORTANT: Do not adjust the
louvres beyond their stops.
5.1.1 List of Components and Instructions to
Fit a Standard 15o Outlet Nozzle (Canopy) on
a Model UF400 (NOTE: A larger optional
nozzle may be fitted rather than the 15o
nozzle. See Section 5.3.)
Identify the following nozzle pieces for a Size 400 heater (Refer to
the illustration in Figure 5).
(1) Remove the horizontal louvre assembly from the heater outlet.
(2) Position either the left or right nozzle side into the heater outlet.
Using the screws and the same holes that held the louvres, attach
the nozzle side to the heater.
(3) Repeat Step 2, attaching the other nozzle side.
NOTE: All screw points should be inside the nozzle.
(4) Position the nozzle top with the tabs down over the sides as
illustrated. Attach to the front of the heater and to both nozzle
sides.
UsestandardM10
nuttopreventrod
fromturning. Donot
useanoversizednut
thatcatchesthe
outersidepanel.
Nozzle
Left
Side
Figure5 -
Fittingthe
Outlet
Nozzle
LouvreFrame
Assembly
Nozzle
Top
Nozzle
Right
Side
4.6 Control Panel Siting
The siting of the controls is particularly important. Avoid locating
the panel in draughty areas or where it may be directly exposed to
heat from the sun or other heat sources. The panel should be mounted
on an internal wall or column about 1.5m above the floor. Follow the
manufacturer’s instructions when fitting the controls. Any thermo-
stat must be suitable for switching 240 volts. Do not attempt to
control more than one heater from a thermostat unless a properly
wired relay is fitted. An Ambi-Rad multi-heater panel is available to
control up to four heaters.

Mfg No. 135847, Page 7
#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. A reading of
approximately 240 volts should be given.
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.
Figure7A-Multifunctional ControlValve (NOTE:Size
UF400maybefittedwiththisvalveorthevalve
illustratedinFigure7B.)
*When measuring gas pressure, do not remove screw.
Loosen enough to allow gas pressure to register.
6.0COMMISSIONINGAND
TESTING
The commissioning and testing should only be carried out by a com-
petent person. This section should be read completely and fully
understood.A commissioningservice isavailable fromAMBI-RAD.
6.1 Electrical Check
After completion of the installation and before switching on the
electrical supply, a preliminary check must be performed by a quali-
fied 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 sizes 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
incomingearth atthe isolator.Aresistance readingof 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.
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 Documents IGE/UP/1.
6.3 Suspension
The suspension of the heater should be checked to ensure that it is
adequate to safely support the heater and that no other parts have
been fitted that are not properly supported or secured. For safe
heater operation, check that the heater is level in all directions.
6.4 Lighting the Heater (Read and Understand
All Steps Before Lighting.)
The following checks should be carried out before attempting to light
the heater.
#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”.
#Turn on the main gas supply to the heater.
6.4.1 Prepare to Light the Pilot
On the bottom rear of the heater, locate the multifunctional control
valve (See Figure 7A or 7B) and the Piezo ignitor knob (Figure 8).
Pressure
Regulator
CoverScrew*
Pilot
Regulating
Screw
Inlet Pressure
Test Port
Outlet
Pressure
Test Port
ControlKnob-
depresswhile
lightingpilot
Gas
Flow
(5)With the remaining screws, fit the louvre assembly into the nozzle
opening. The louvres may be adjusted from 10 to 55 degrees to
direct the airflow down to the floor. IMPORTANT: Do not ad-
just the louvres beyond their stops.
5.2 Vertical Louvres (Option CD1)
Model UF heaters 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 assembly is designed to be assembled and fitted at the instal-
lation site. Complete instructions including a parts list are packaged
with the option. Refer to Figure 6.
5.3 Downturn Air Nozzles (Options CD2,
CD3, and CD4)
Model UF heaters can be fitted with optional downturn nozzles to
direct the discharge air toward the floor. This option is normally used
with heaters that are installed at heights above the minimum recom-
mended. Option CD2 is a 30o downturn nozzle which changes dis-
charge air direction up to 57o. Option CD3 is a 60odownturn nozzle
which changes discharge air direction up to 90o. Option CD4 is a 30o
downturn nozzle with vertical louvres. Do not fit vertical louvres on
a Model UF with Option CD3, 60o Nozzle.
All downturn nozzles are designed for site assembly and fitting. Each
option package includes complete assembly and installation instruc-
tions.
Size 400 heaters must be fitted with an outlet nozzle (canopy).
Figure6 -
ModelUF
400
witha
standard15o
Canopyand
Optional
Vertical

Form WA004, Page 8
6.4.2 Light the pilot
Depress the knob or button (See Figure 7A or 7B) on the multifunc-
tion control valve. Continue to hold the knob or button depressed
while turning the knob on the Piezo ignitor. NOTE: On initial light-
ing, it may take some time to purge the pilot pipework of air.
6.4.3 Once the pilot is established (visible through the viewing
port), continue to depress the knob or button on the gas valve for 20
seconds and then release slowly.
WARNING:Ifforanyreasonthepilotlightgoes
out,allowthreeminutesbeforerelighting.
Close the bottom panel.
6.4.4 Adjust room temperature control setting to above the ambi-
ent temperature. The main burners will light (the main burners can be
seen through the viewing port).
6.4.5 TO TURN OFF THE HEATER —
Pilot and Main Burner:
Valve in Figure 7A - Rotate the knob on the multifunctional
valve in a clockwise direction.
Valve in Figure 7B - Push in and release the red stop button
(marked O) on the valve.
WAIT THREE MINUTES BEFORE
RELIGHTING THE HEATER.
Figure9 -
PilotFlame
Adjustment
6.8 Air Distribution System
The system should be checked to ensure that the installation work
has been carried out in accordance with the design requirements.
Figure7B - SizeUF400MultifunctionalControlValve
(NOTE:SizeUF400maybefittedwiththisvalveorthe
valveillustratedin Figure 7A.)
6.4 Lighting the Heater (cont'd)
6.4.1 Prepare to Light the Pilot (cont'd)
Start
Button Stop
Button PressureRegulator
CoverScrew
PilotRegulating
Screw Outlet Pressure Test Port
6.5 Heater Pipework
The soundness of the heater’s pipework has been checked at the
factory. However, during shipment or installation, connections may
have 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
checking the soundness of any 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 2, Technical Data (Table 2), the correct
burner pressure for the heater.
2) Turn the room temperature control to lowest temperature set-
ting.
3) Loosen the screw from the outlet pressure test point of the gas
valve (See Figure 7). Connect a manometer to the test point.
4) Light the pilot as detailed in Section 6.4. Adjust the room tem-
perature control to above ambient temperature.
5) Observe the gas pressure on the manometer and compare to the
required burner pressure.
6) If necessary, adjust the burner gas pressure. Remove the cover
screw (Figure 7). Turn the regulator screw anti-clockwise to de-
crease the pressure or clockwise to increase the pressure.
7) Set the room temperature control to the lowest setting to turn off
the main burners. Tighten 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.
6.6.2 Pilot Flame Adjustment
The pilot regulating screw is contained in the multifunctional control
valve (Figure 7). The pilot regulating screw leaves the factory set for
maximum pilot rate. If the gas inlet pressure to the heater exceeds 25
mbar, the pilot rate should be reduced. Remove the cover screw. To
adjust the pilot flame, screw the adjusting screw clockwise to reduce
the flow. Figure 9 shows the approximate flame length. Replace the
cover screw after pilot adjustment is completed.
6.7 Draught Diverter
Ascertain that there is no spillage of products of combustion from
the heater draught diverter by carrying out a spillage test, as detailed
by BS5440, Part 1, ensuring that any extract fans in the area are
turned “on”.
Figure8-Rear of heater showingthegasvalveandthe
knobonthePiezoignitor
IgnitorKnob Depressknobon gasvalveand
holdwhileturning ignitorknob.

Mfg No. 135847, Page 9
7.0SERVICINGINSTRUCTIONS
WARNING:Onlycompetent and qualified engineersshould carryoutservicing andfault findingon
thisequipment. Complete after-sale serviceis availablefrom AMBI-RAD.
Beforemaintenanceiscarriedout, ensure that both gas andelectrical supplies are turnedoff and the
applianceiscold.
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.
NOTE 1: Check all pipe joints for gas soundness. Any leaks found must be repaired before leaving the heater in operation.
NOTE 2: After routine maintenance, the commissioning procedure, Section 6, should be carried out to ensure efficient and safe
operation.
7.1 Servicing Procedure
The following procedures should be carried out at least annually:
Adjust the discharge louvres to provide a satisfactory spread of
heatedair. Direct the heated air to the floor avoiding direct draught on
personnel who may be working nearby.
CAUTION: To avoid getting burned, adjust
louvrespriortoheateroperation.Iflouvresneed
re-adjustingafterstartup,wearprotectivegloves.
6.9 Heater Controls
Check heater operation after all adjustments have been carried out.
Set the room temperature control to above ambient temperature. The
main burner should light. Within approximately 30 seconds, the fan
thermostat control will sense a rise in the temperature of the heat
exchanger and energize the fan 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 operate. If for any reason, the limit switch is tripped,
the cause must be determined. See Paragraph 8.8 and Fault Finding
Chart, Section 10.3.
Turn the room temperature control to lowest temperature setting.
The main burners should extinguish while the fan 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
motor.
6.10 Handing Over
Upon the satisfactory completion of commissioning and testing,
hand the instructions to the user or purchaser. Advise the user/pur-
chaser how to safely use and operate the heater, including all associ-
ated equipment and controls. Ensure that the user/purchaser under-
stands how to light the heater and 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.
Figure10-PilotAssembly(lessthermocouple)
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 with solvent and compressed air. CAUTION: Wearing eye
protection is recommended.
b) Checkthe condition of the electrode and clean with an emery cloth. Remove all
deposits.Check the spark gap at the tip of the electrode; spark gap should be
2.5mm.
c) Check the condition of the thermocouple and
clean off any deposits. If signs of erosion are
visible, renew the thermocouple as in Sec-
tion 8.2.
d) Clean any deposits from the main burner,
paying particular attention to lint or fluff,
etc., which may have formed around the in-
jectors in the venturi of the burner. Clean
using compressed air and a soft brush. CAU-
TION: Wearing eye protection is recom-
mended.
d) Clean any deposits from the burner tray.
2. The heat exchanger should remain clean unless
some problem has developed with combustion.
Examinethe heatexchanger internallyand exter-
nally for any sign of deterioration.
3. The fan blade, fan guard and motor should be
cleaned to remove any build up of dust, fluff,
etc.
4. Ensure that any purpose-provided air vents for
ventilationand combustion arefree from obstruc-
tion.
5. The flue system should be checked for sound-
ness. Reseal/replace any parts that do not ap-
pear sound.
6. Check the wiring for any signs of damage. Re-
place wiring with an equivalent specification.
7. When service is complete, carry out commis-
sioning procedure, Section 6.0-6.8.

Form WA004, Page 10
7. To remove the individual burners from the burner assembly:
a) With the burner assembly upside down, remove the screws (lo-
cated at the rear) that secure the retaining bracket.)
b) 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).
Figure 12 - Location of Burner Support Retaining Screws
Screws
Figure16-IndividualMain
Burners
Figure 11 -
ConvenientBottom
Access
Pilot
Location
Push hinge
pinto
remove
bottom
panel.
8.0 REMOVAL AND REPLACEMENT OF PARTS
6. Allow the front of the burner assembly to drop down. Lift up on
the rear part to disengage it from the locating slots at the mani-
fold, and slide the whole assembly out.
Figure 15-BurnerRackRemoved(topview)
Figure 17
Figure 13 -
Burner
Rack
Hinged
Down
MainBurnerInjectors
BurnerAssemblySupportBrackets
Figure 14
WARNING: To comply with legislation, only
certificated spares may be fitted to heaters
supplied after 1/1/96. A full spares service is
providedbyAMBI-RAD. Onlyacompetentand
qualifiedengineershouldcarryoutservicing on
this equipment. Before maintenance is carried
out,ensurethatboth gas and electrical supplies
areturnedoffandtheapplianceiscold.
After maintenance work, the heater MUST be
fullycommissioned(See Section 6).
8.1 Main Burner Removal
Model UF units have been designed with convenient bottom access.
The pilot is attainable with the bottom access panel open. With the
access panel removed, the burner rack assembly will hinge down for
removal. Use the following step-by-step instructions for removal of
the bottom access panel and the burner rack assembly.
Instructions for Burner rack Removal (Refer to Figures 11 to 17
inclusive):
1. Remove the two screws located at the rear bottom panel.
2. Allow bottom panel to hinge down from the front. Refer to Fig-
ure 11.
3. Push in one of the two spring-loaded hinge pins located at the
front of the bottom panel (inside), and completely remove the
bottom panel.
4. The bottom of the pilot is now visible (See Figure 11).
a) Disconnect the pilot tubing from the multifunctional control
valve and the pilot burner taking care not to lose the pilot
injector which is located inside the pilot burner and fitted
over the pilot burner tube.
b) Disconnect the thermocouple from the multifunctional gas
control valve and from the pilot burner assembly.
5. Remove the sheetmetal screws (two or three) located at the front
of the burner assembly. (See Figure 12.) These screws retain the
slotted burner support bracket. Remove the bracket taking care
to support the burner assembly.

Mfg No. 135847, Page 11
8.3 Pilot Burner Injector
1. Carry out Steps 1 to 2 of Section 8.1.
2. The bottom of the pilot is now visible (See Figure 11). Discon-
nect the pilot tubing from the pilot burner.
CAUTION:Takecarethatthepilotinjectordoes
not fall out of the pilot burner (located on the
endofthepilotsupplytube.)
3. Fit a new pilot burner injector. The injector for natural gas is
stamped #7718.
4. Re-assemble in reverse order.
8.4 Pilot Burner Assembly (See Figures 14
and 17)
1. Carry out Steps 1 to 2b of Section 8.2.
2. To remove the pilot assembly, remove its two fixing screws.
3. Refit the new pilot burner by re-assembling in reverse order.
4. Check relationship of the pilot burner with the adjacent main
burner. Refer to Figure 17.
8.5 Main Burner Injectors
1. Remove the two screws located at the rear of the bottom panel.
Allow the bottom panel to hinge down from the front.
2. Unscrew the main burner injectors (See Figure 14).
3. Re-fit new injectors
4. Re-assemble in reverse order.
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. Al-
ternately blow through burner ports and venturi. Use fine wire to
dislodge any stubborn particles. Do not use anything that might
change the port size.
8. Re-assemble in reverse order.
9. When lighting, alwaysfollowthelighting instructions ontheheater.
After any service work, the heater must be fully commissioned.
See Section 6.0-6.8.
NOTE: Use only factory-authorised replacement parts.
Heaters supplied after 1/1/96 must use certificated spares to
complywith legislation. Acompletespares serviceisavailable
fromAMBI-RAD.
8.2 Thermocouple
1. Carry out Steps 1 to 2 of Section 8.1.
2. The bottom of the pilot is now visible. (See Figure 11.)
a) Disconnect the thermocouple from the multifunctional control
valve.
b) Disconnect and remove the thermocouple from the pilot burner
assembly.
3. To fit a new thermocouple, push fully home up to the shoulder and
tighten the compression nut to secure the thermocouple in place.
Re-assemble by reversing the above procedure, bending the ther-
mocouple to follow its original path. (Do not use excessive force
when fitting a thermocouple into the valve. This is an electrical
connection which must be kept clean. Do not over tighten).
8.6 Fan Motor/Blade
Replacement of Fan Motor and/or Blade — Model UF
Follow these instructions for removal and replacement of fan motor
and/or fan blade.
1. Remove left hand side panel (left when facing the rear of the unit)
by unscrewing its seven fixing screws (4 front and 3 back).
2. Disconnect the fan motor wires and push out the cable retaining
gland.
3. To remove the sub-assembly including the fan motor, the blade,
and the fan guard, remove the eight screws that attach the fan
guard to the heater.
4. Either the fan motor, fan blade or both may now be replaced.
Space the fan blade on the shaft as shown in Figure 17.
Motor
FanHub
Figure17-CorrectSpacingofthe Fan Blade on the
MotorShaft
"A"
Model "A" -- Hub to Motor Spacing
UF mm
25 32
50 10
75 16
100 - 400 63
8.7 Multifunctional Control Valve (See
Figure 18)
1. Ensure the electrical supply is isolated.
2. Disconnect the thermocouple and the pilot supply tube.
3. Removethe terminalcover and disconnect the electricity connec-
tions.
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
includingflange connectionswith O-rings. ReplaceO-rings when
fitting a new valve.
6. Carry out a complete commissioning procedure. Refer to Sec-
tions 6.0 to 6.8.
Figure18-MultifunctionalControlValve
(Note:Thevalve onaSize400may be differentfromthis
illustration.)

Form WA004, Page 12
8.8 Limit Control Switch (Overheat
Thermostat)
This heater is fitted with two temperature-activated limit con-
trol switches that when activated will interrupt the electrical
power to the gas valve. The limit in the "lower" portion of the
airstream is a manual reset type limit switch, which if acti-
vated, must be reset before the pilot light can be relit. The
manual reset limit is reset by depressing the small button in
the center of the switch body. The reset button is accessible
without removing the heater outer side panel. The limit in the
"upper" portion of the airstream is an auto reset switch. If the
auto reset limit is activated, it must be sufficiently cooled be-
fore the pilot can be relit. (See Section 8.0).
If it is determined that either limit control switch needs replacing, use
only a factory-authorised replacement.
8.8.1 Instructions for Replacement of Limit Switch
Control
Model UF heaters manufactured prior to 3/97 have only a manual
reset limit control; see Figure 20. Model UF heaters manufactured
beginning 3/97 have a manual reset limit control and an automatic
recycling limit control; see Figure 19.
Instructions for Replacement of the Limit Switch Controls on
Model UF Series 2 heater with both a manual reset limit and
an automatic recycling limit (manufactured beginning 3/97).
Refer to Figure 19.
8.0 REMOVAL AND REPLACEMENT OF PARTS (cont'd)
1. Remove the outer side panel (left when facing the rear of the
heater).
2. Remove the limit switch and replace with a replacement switch
listed above.
Automatic Reset Limit (located on the upper left
corner of the side panel)
a) Disconnect the wires from the limit control switch.
b) Remove the screws holding the limit control switch.
c) Fit the replacement limit switch by reversing the procedure.
Manual Reset Limit (located on the lower right
corner of the side panel)
a) Disconnect the limit switch wires from the gas valve.
b) The manual reset limit switch has a capillary sensing tube that
stretches across the air discharge. To remove the switch and cap-
illary -- (1) pull the copper-coloured capillary tubing out of the
tube that is fitted across the heater discharge; (2) remove the
screws holding the limit switch; (3) pull the capillary tubing out
through the plastic retainer clips on the side of the heater.
c) Fit the replacement limit switch by reversing this procedure. Be
sure that the capillary tube is stretched across the full width of
the discharge opening. Depending on the heater size and tube
length, a loop may have to be made in the capillary tube between
the plastic retainer clips and where it enters the heater side panel.
Be careful not to kink or squeeze the capillary tube.
3. Replace the outer side panel. Carry out a complete commission-
ing procedure. Refer to Section 6.0-6.8 in the heater installation
manual.
Instructions for Replacement of the Limit Switch on a heater
with only a manual reset limit located on the upper left corner
of the side panel (manufactured prior to 3/97). Refer to Figure
20 below.
Terminal Block
withLimit
ControlWires
ManualReset
LimitSwitch
Controlwith
CapillaryTubing
Figure20-Heatermanufactured
priorto3/97withonemanual reset
limitcontrol
Figure19-Heater manufactured beginning 3/97with
onemanualreset limit controlandoneautomaticreset
limitcontrol
Automatic
reset limit
isasnap
disctype
limit.The
limitmust
be
sufficiently
cooled
beforethe
heaterwill
operate. Manualresetlimit
withacapillary
sensingtube.A
holeintheouter
sidepanelallows
thelimitto be
reset.

Mfg No. 135847, Page 13
8.9 Fan Temperature Control
The fan temperature control senses the temperature of the heat exchanger. 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.)
TheFanControl is seatedontheheat
exchanger
RemoveAccessPanel
Instructions for Replacement
of Fan Temperature Control
(See Figure 21)
1. Remove the outerleft sidepanel (left
when facing the rear of the heater).
2. Remove the small access plate on
the inner side panel.
3. Remove defective controland install
new control in the same mounting
holes
4. Re-fit access panel and outer side
panel.
5. Turn on the electricity supply and
the gas service valve. Carry out a
completecommissioning procedure.
Refer to Sections 6.0 to 6.8.
Figure21-FanControl
1. Remove the outer side panel (left when facing the rear of the
heater).
2. Remove the small access plate on the inner side panel.
3. Remove the retaining bush holding the two limit wires
4. Disconnect the limit wires from the gas valve and feed wires
through.
5. Remove the two retaining screws holding the limit control switch
capillary assembly bracket to the inner side panel and withdraw
the assembly.
6. Remove the limit switch control from the bracket by removing
the two retaining screws.
7. Replace the limit control switch and assembly in reverse order,
ensuring that the capillary tube extends across the full width of
theheat exchanger.
8. Carry out a complete commissioning procedure. Refer to Section
6.0 to 6.8.

Form WA004, Page 14
9.0CIRCUIT DIAGRAMS
9.1 Remote Diagram - Model UF Series 2
NOTE: Where an Ambi-Rad panel is used, consult the wiring diagram supplied with the panel.
9.2 Circuit Diagram -
Model UF Series 2

Mfg No. 135847, Page 15
Is the thermostat
above room temperature
and if used, is the time
clock "ON"?
Set the thermostat
above room
temperature and if used,
make certain time clock
in "ON".
Is the pilot
alight?
Is the overheat
limit tripped?
Determine the
cause. Refer to
Fault Chart 10.3.
Light the
pilot.
Does the
pilot remain
alight?
Refer to Fault
Chart 10.2.
Okay
Is there
220 to 250 volts between
L and N?
Check the
mains.
Is there
voltage between 1
and N at site wiring
terminal block?
Check thermostat
and if used, time
clock. Check wiring.
Is the
multifunctional
gas control valve turned
to "ON"?
Rotate knob to
"ON" position.
Is there 220
to 250 volts at the
multifunctional
valve?
Replace
multifunctional
control valve.
Check and
correct wiring.
NO
YES
NO
YES
YES
NO NO
YES
NO
YES
NO
YES
NO
YES YES
NO
10.0FAULT FINDINGCHARTS
WARNING: Fault finding should only be carried out by a competent service engineer.
10.1 Main Fault Finding Chart

Form WA004, Page 16
10.0 FAULT FINDING CHARTS (cont'd)
10.2 Pilot Does Not Remain Alight
Is the gas
supply pressure 20
mbar?
Correct the
gas supply
pressure.
Refer to Figure
10. Does the pilot flame
adequately impinge on the
thermocouple?
Adjust pilot flame. Refer to
6.7.2 and/or check pilot
injector for dirt. Clean with
solvent and compressed
air. DO NOT REAM!
Is the
overheat limit tripping
during heater
operation?
Refer to Fault
Chart 10.3.
Is the
thermocouple's
closed circuit millivoltage
output at least 8
MV?
Replace the
thermocouple.
Are all the
connections clean
and firmly made?
Clean and
secure.
Check pilot safety
valve. If defective,
replace multifunctional
gas control valve.
NO
YES
NO
YES
YES
NO
NO
YES
NO
YES

Mfg No. 135847, Page 17
UF MODELS
Is the fan guard and/or
fan blade covered
with dirt?
Clean to remove
accumulated dirt
Adjust thermostat
temperature setting above
ambient to energise fan
and gas solenoid valve.
Does the
fan motor operate?
Is there 220 -
250 volts at terminals
N and 3?
Replace fan
motor.
Consult Fan
Fault Finding
Chart 10.4.
Has any
non-factory authorised
air distribution device been
placed on the
heater?
UF MODELS
Remove restriction
from appropriate
components.
Does the fan
control energise the fan
motor in less than 75
seconds?
Consult Fan
Fault Finding
Chart 10.4.
Does the limit
trip before the fan is
energized?
Check for
excessive main
burner pressure.
Place system in
normal
operation.
YES
NO
NO
YES
YES
NO YES
NO
NO
YES
YES
NO
NOTE: Interruption of the main electrical
supply to the heater when the heater is in
operationmay causethe limitcontrol totrip.
Check that the supply to the heater is not
being interrupted incorrectly by
(a) Incorrect wiring of the time clock.
(b) Fire alarm systems, etc.
(c) Isolation of main feed to building.
10.3 Limit Control Fault Finding Chart (Limit Control Trips)

Form WA004, Page 18
10.0 FAULT FINDING CHARTS (cont'd)
10.4 Fan Fault Finding Chart
Is the ambient
temperature less than 5
degrees C? Fit fan start relay.
Is the
fan control firmly
seated against the heat
exchanger tube (refer to
Section 8.9)?
Check for low
main burner
pressure.
Correct the fan
control seating.
See Figure 21.
YES
NO
YES
NO
Adjust thermostat
temperature setting
above ambient to
energise the fan and gas
solenoid valve.
Does the fan
operate?
Place the system
in normal
operation.
Is there 220 -
250 volts at Terminals
N & 3?
Replace fan
motor.
Is the
fan control firmly
seated against the heat
exchanger tube (refer to
Section 8.9)?
Replace fan
motor.
Correct the fan
control seating.
See Figure 21.
YES
NO
YES
NO
YES
NO
10.4.1 Fan Fails to Operate
10.4.2 Fan Motor Cycles During Operation

Mfg No. 135847, Page 19
Is the
pilot burner
alight?
Is the main
gas burner knob
"ON"?
Replace the
gas valve.
Rotate to
"ON" position.
Does the
heater have a
manual reset limit? See
Section 8.8?
Is the limit
tripped?
Relight the pilot
burner. See
Section 6.4.2.
Reset limit and
determine cause.
Relight the pilot
burner. See
Section 6.4.2.
Relight the pilot
burner. See
Section 6.4.2.
YES
NO YES
NO
YES
NO
NO
YES
10.5 No Main Burner Gas Flow Fault Finding Chart (220/250 volts at multifunctional control
valve.)

Form WA004, Page 20
11.0 SHORT LIST OF PARTS
A "replacement parts tag" listing the most common replacement parts is affixed to the rear of the heater. Each tag is "custom made" for
that particular size and style of heater. See Figure 22 for an example of a Replacement Parts Tag.
The list below includes only controls used on currently manufactured Model UF-2 heaters. For other Model UF-2 replacement parts,
see replacement parts lists on pages 21-23.
Figure22--Example ofaReplacementPartsTag
(Example applies to Model UF200. Each heater has a Replacement Parts Tag.)
COMMONREPLACEMENTPARTSFOR:
MODEL: UF200
SERIALNUMBER:
WHEN ORDERING PART, ALWAYS GIVE THE FULL MODEL
NUMBER AND SERIAL NUMBER
FAN OR BLOWER MOTOR .........................121277
FAN CONTROL ............................................ 123974
MANUAL RESET LIMIT CONTROL .............. 151790
AUTOMATIC LIMIT CONTROL SWITCH ....... 57953
PILOT............................................................133636
THERMOCOUPLE ........................................125835
GASVALVE ....................................................113766
HEATEXCHANGER ......................................102287
SIZE
25-2 50-2 75-2 100-2 125-2 165-2 200-2 250-2 300-2 400-2
Pilot Burner Assembly including
Injector and Thermocouple for units
with a Piezo ignitor - Natural Gas
173039 173039 173039 173039 173039 173039 173039 173039 173039 173039
Thermocouple 125835 125835 125835 125835 125835 125835 125835 125835 125835 125835
Pilot Injector only - Natural Gas 103034 103034 103034 103034 103034 103034 103034 103034 103034 103034
Pilot Injector only - Propane Gas -- 98695 98695 98695 98695 98695 98695 98695 98695 98695
Piezo Ignitor (less Knob) 173036 173036 173036 173036 173036 173036 173036 173036 173036 173036
Piezo Ignitor Knob 173037 173037 173037 173037 173037 173037 173037 173037 173037 173037
Fan Control with Bracket 123974 123976 123976 123976 123976 123976 123974 123974 123974 123974
Fan Control only 146465 146464 146464 146464 146464 146464 146465 146465 146465 146465
ManualReset Limit Controlwith
Capillary Sensor 151789 151789 151789 151789 151789 151790 151790 151791 151791 151791
Automatic Reset Limit Control 50418 57953 57953 57953 57953 15792 57953 57953 57953 57953
Main Burner Assembly 94777 94777 94777 94777 94777 94781 94781 94781 94781 94781
No. of Burners (2) (3) (4) (5) (6) (5) (6) (8) (9) (12)
Injector - Main - Natural Gas 36950 84853 38678 11833 11833 11831 11831 11831 11831 11831
Injector - Main - Propane Gas -- 63003 64676 11830 11830 96344 96344 96344 96344 96344
No. of Injectors (2) (3) (4) (5) (6) (5) (6) (8) (9) (12)
Gas Control (Valve) - Natural Gas 113766 113766 113766 113766 113766 113766 113766 113766 113766 113766
Fan Motor 133789 133789 133789 121277 121277 121277 121277 172794 172794 172794
Component