HVACopediaGoodman · Furnace troubleshooting
External gas valve error (valve not energized when it should be)
What is going on
The control is calling for the gas valve and it isn't energizing. Before touching anything, turn the power off. This points at the valve circuit or the control relay, not the gas supply, so don't start poking at gas piping.
Likely causes
- Miswired gas valve circuit
- Open gas valve circuit
- Gas valve relay on the integrated control board stuck open
Check in this order
- Shut off power at the disconnect before working on the valve wiring.
- Check the wiring in the gas valve circuit against the wiring diagram.
- Look for loose or broken connections and a pulled plug at the valve.
- With power restored and a call for heat, confirm the control is sending voltage to the valve.
- If voltage is present at the valve and it won't open, the valve is suspect and needs a licensed technician.
- If the relay is stuck open, replace the integrated control board with the correct part.
Applies to: 34.5 in chassis gas furnaces
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- Annual inspection checklist
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Source: Goodman GMVC96 Service and Troubleshooting, p. 61. Written in our own words; check the manual for your exact model.
For licensed technicians. Gas, electrical and refrigerant work must be done by a qualified, licensed person. Shut off power and gas before servicing, never bypass a safety control, and follow the manufacturer’s manual for the exact model; it and local codes always take priority. HVACopedia is not affiliated with any manufacturer; brand and model names only identify the equipment.