SECTION 12: U
SER
I
NSTRUCTIONS
33 of 55
SECTION 12: USER INSTRUCTIONS
The UHD[T][M][X][S][R] Series heaters are fully
automatic and operate from the external controls
fitted on site.
12.1 Heater Operation
When the heater has been switched on by the
thermostat installed on site, the main burner will
automatically turn on.
The burner control module will control the safe
ignition of the flame.
If equipped with two stage gas valve, the heater may
start in low or high fire.
If equipped with a modulating gas valve, heater will
start at firing rate called for by modulating
thermostat. Heater will continue to run at firing rate
called for by thermostat, with 10 VDC being
maximum rate and 0 VDC being minimum rate. ON/
OFF control is provided by thermostat R and W
connections.
See Page 20, Section 10.2
.
All heaters require a constant gas and electricity
supply which must not be interrupted during the
normal operation of this heater.
12.2 Lighting Instructions
12.2.1 To Turn On Heater
1. Ensure that the electrical and gas supplies to
the heater are on. Check that the on site
controls are
"
ON
"
.
IMPORTANT:
The thermostat setting must be above
the ambient temperature for the heater to operate.
2. The automatic firing sequence will begin as
described
on Page 29, Figure 14
. The heater
will now operate automatically under the control
of the on site controls.
12.2.2 To Turn Heater Off
Set the thermostat to the
"
OFF
"
position or lowest
setting.
The burner will turn off immediately.
To restart, turn the thermostat on or above room
temperature.
12.3 Simple Troubleshooting
Some possible reasons for the heater not operating
are:
1. Gas supply not
"
ON
"
.
2. Electricity supply not
"
ON
"
.
3. The time and/or temperature controls are not
"
ON
"
.
4. A limit switch may have operated. This may be
caused by an interruption of the electrical
supply, failure of the distribution fan or vent or
heat exchanger blockage.
If a temperature limit switch persistently trips, there
is a fault which must be investigated by a contractor
qualified in the installation and service of gas-fired
heating equipment.
12.3.1 Simple Troubleshooting (Burner Faults)
If the burner fails to ignite for any reason, it will retry
for ignition (four trials total). After four unsuccessful
ignition trials, the control will put the heater into
lockout for one hour.
Lockout should not occur during normal operation of
the heater and indicates there is a fault condition
which must be corrected. There is an LED light on
the ignition control that flashes codes to assist in
fault correction.
See Page 34, Figure 18
for LED
indication codes.
Cut/Pinch Hazard
Wear protective gear
during installation,
operation and service.
Edges are sharp.
WARNING
Failure to follow these instructions can result in death, electric shock, injury or property damage.
Burn Hazard
Allow heater to cool
before service.
Tubing may still be hot
after operation.
Explosion Hazard
Turn off gas supply to
heater before service.
DANGER
Electrical Shock Hazard
Disconnect electric
before service.
Heater must be
connected to a properly
grounded electrical
source.
Summary of Contents for UHD150
Page 2: ......
Page 4: ......
Page 8: ......
Page 27: ...SECTION 9 GAS PIPING 19 of 55 Figure 13 Gas Connection...
Page 47: ...SECTION 14 TROUBLESHOOTING 39 of 55 14 1 General...
Page 62: ...UHD STANDARD DUCT FURNACE INSTALLATION OPERATION AND SERVICE MANUAL 54 of 55...
Page 64: ......
Page 65: ......
Page 66: ......
Page 67: ......
Page 68: ......
