Originally Posted by kok328
Your jumping all over.
Use a systematic approach to troubleshooting.
Start with line power and then check control power.
Part of what I do not know is order of operation of a furnace.
No Idea. If anyone can provide this, would be a great help!
Part of my initial problem was the multi-meter I have was suspect, so some of the first troubleshooting was not accurate.
This is what I know/done:
1. First noticed an issue. Induction fan would run, nothing else.
2. The LED was flashing 3x. According to manual this is a vacuum switch/induction problem.
3. Replaced vacuum switch, no change.
4. Checked resistance of both switches. Both are OK. When induction fan OFF = infinite ohms. When induction fan ON = 0 ohms.
5. Checked resistance of HSI = 53.9 ohms.
6. Double checked all incoming voltages (with new multi-meter). Got 120 VAC at main on/off switch, junction box going into furnace and at the transformer.
7. Checked voltage going into the HSI. Getting ~1 VAC. But again I do not know the order of operation.
So I do not know if this should be ON or OFF yet.