COMBAT® UHA UNIT HEATER INSTALLATION OPERATION AND SERVICE MANUAL
SECTION 11: USER INSTRUCTIONS 11.1 User Instructions
The UHA(S) Series heaters are fully automatic and operate from the external controls fitted on site.
WARNING
Electrical Shock Hazard
Disconnect electrical power before servicing.
Failure to follow these instructions can result in death or electrical shock.
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.
11.3Common User Controls
11.4Lighting 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 20, Figure 10. 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. To restart, turn the thermostat above room temperature.
11.5 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
11.5.1 Simple Troubleshooting (Burner Faults)
If the burner fails to ignite for any reason, it will retry for ignition (4 trials total). After 4 unsuccessful ignition trials, the control will put the heater into lockout for 1 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 Figure 12 for LED indication codes.
Figure 12: LED Diagnostic Codes
LED INDICATION | FAULT MODE |
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Slow Flash | Normal Operation - No call for heat. |
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Fast Flash | Normal Operation - Call for heat. |
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2 Flashes | Ignition Lockout - No flame detected. |
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3 Flashes | Airflow Fault - Pressure switch open or closed. |
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4 Flashes | Temperature Limit or |
| Manual Reset Limit Switch Open |
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5 Flashes | Flame Sense Error - Gas valve not energized. |
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Steady On | Internal Control Failure |
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