SAIL SWITCH VOLTAGE CHECK
Hoping for help on troubleshooting a Furnace Sail Switch. Furnace was intermittently failing and now progressively worse. Blower would come on and after about 30 seconds would shut off - no audible at...
Forum Discussion
BFL13 wrote:
I don't understand why it matters what the voltage is when it is open. The thing is, when it is closed and the squirrel cage is turning, the gas valve does not open. If it is not rotating fast enough, the sail switch does not close, but it does, the OP reports, so it is turning fast enough.
So the question is why doesn't the gas valve open. I assume it quits because there was no flame, so that part works.
This problem "got worse" so maybe wasp nests? Except there was no gas valve opening he said.
READ my response. THAT is why voltage matters. IF you close the sail switch manually BEFORE the furnace operates(to test the sail switch), nothing will happen because the CB "sees" that the switch is closed and will not operate the furnace. Older models with older style CB's you can test a sail switch this way. Doug
