I've run into a problem with my Goodman GMH95 furnace not igniting...
Background: At the beginning of summer, the capacitors in my AC condenser outside caught fire. It roasted the wires in the condenser, shorted out the compressor and fried the control board in my furnace. I replaced the AC condenser and the control board in the furnace. The AC has been working great all summer.
Now we've had a few cooler nights and it (finally) occurred to me that I had not checked the heat. So I turned the thermostat up. Guess what? No heat. I noticed a char mark on the connector for the gas valve and replaced the gas valve yesterday. Still no heat.
Here's what happens:
- I turn the thermostat up to call for heat.
- The draft inducer fan starts.
- The pressure switches both close (one on the blower box, one on the coil? cover).
- The igniter starts glowing and glows for about 10 seconds.
- After about 5 seconds, the gas valve receives 24V on the orange wire for about 3 seconds while the igniter is on. I do not hear any click or smell any gas from the gas valve.
- The igniter turns off.
- The blower runs for about 15 seconds longer.
- The blower shuts off.
- Repeat steps 2-8 two more times.
I checked the pressure switches by applying vacuum and monitoring the resistance across the sensors. Both close at very low vacuum. I can also hear both close when the draft inducer fan turns on.
I cleaned the flame sensor for good measure.
I'm wondering if I got a bad gas valve. It was an eBay purchase of a (supposedly) new part. I imagine it's possible I got a bad one.
What else should I check before I buy another gas valve?