UHD STANDARD DUCT FURNACE INSTALLATION OPERATION AND SERVICE MANUAL
SECTION 11: USER INSTRUCTIONS
WARNING
Explosion Hazard
Installation, service and annual inspection must be done by a contractor qualified in the installation and service of
Turn off gas and electrical supplies before performing service or maintenance.
Failure to follow these instructions can result in death, injury or property damage.
11.1 User Instructions
The UHD[X][S][R] Series heaters are fully automatic and operate from the external controls fitted on site.
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.
11.3Lighting Instructions 11.3.1 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.
The automatic firing sequence will begin as described on Page 22, Figure 11. The heater will now operate automatically under the control of the on site controls.
11.3.2 To Turn Heater Off
Set the thermostat to the "OFF" position. The burner will turn off immediately.
To restart, turn the thermostat above room temperature.
11.4 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
11.4.1 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 24, Figure 13 for LED indication codes.
Figure 13: 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 |
| 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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