- Burner is either not lighting or not staying lit during ignition cycle.
- Check inlet gas pressure for minimum pressure on rating label.
- Can you hear sparking to the burner?
- Check high voltage cable connections.
- Check inlet gas pressure to the gas valve making sure the pressure is within the limits specified on the rating label.
- Check gas valve wire harness for broken wires or shorts.
- Check outlet gas pressure.
- If 24 volts is present to the terminals at the gas valve, replace gas valve.
- Check for voltage output to the blue gas valve wires on the control board pins.
- If during the ignition trial period, there is no voltage present at the control board pin terminals for the blue wires leading to the gas valve, then replace the control board.
- Replace spark rod if insulator is damaged or rod is loose.
- Check to make sure combustion blower is operating when thermostat calls for heat.
- If blower is not running check for 120 volts to blower harness and then at blower pin connections.
- Replace control, wire harness, or blower if defective.
- Check to make sure vent terminals are clear of debris or snow and ice. Make sure the condensate drain flows freely.
