Service manual

COMBAT
®
UH UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL
26
SECTION 11: USER INSTRUCTIONS
11.1 User Instructions
The UH (A) (AS) Series heaters are fully automatic
and operate from the external controls fitted on site.
The only user control at the heater is the Manual
Reset Limit Switch - See Page 26, Section 11.3.1
11.2 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 box will control the safe ignition
of the flame.
All heaters require a constant gas and electricity
supply which must not be interrupted during the
normal operation of this heater.
11.3 Common User Controls
11.3.1 Manual Reset Limit Switch
On residentially approved models, the limit
thermostat is located inside the access door of the
heater. See Page 37, Section 14.3. This control
protects against excessive heat build-up inside the
burner compartment.
Figure 15: Manual Reset Limit Switch
11.4 Lighting Instructions
11.4.1 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”.
NOTE: 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 23, Figure 12. The heater
will now operate automatically under the control
of the on site controls.
11.4.2 To Turn the Heater Off
Set the thermostat to the “OFF” position.
The burner will turn off immediately.
The fan will continue to run for 90 seconds.
WARNING
Electrical Shock Hazard
Disconnect electrical power before servicing.
Failure to follow these instructions can result in
death or electrical shock.
Reset Button
To reset manual reset limit switch, press reset
button. NOTE: To reset, the switch must be cool.
Description Part Number
Manual Reset Limit Switch 90412106
WARNING
Explosion Hazard
If manual reset limit switch locks out, do not
make more than one attempt to restart the heater.
The vent or heat exchanger may be blocked.
The fault must be traced and repaired.
Failure to follow these instructions can result in
death, injury or property damage.