I trigger the furnace using the TEST lead to the common lead. The inducer motor starts (somewhat slowly), the ignitor glows, missing gas flow rom the GSV and then the blower tuns on and then shuts off. No fault code. I replaced the gas valve, no change. I checked the pressure switch for the draft inducer motor and that appears to be good when I suck into it through the tubing, the swicth opens and closes, I measured with multimeter for resistance. In circuit the switch will not close, I don't read 24 VAC from any terminal lead to grnd. Is it the inducer motor because it is not providing enough back pressure? Help. The inducer motor squeels upon start up, appears slow.

Checking the volatges on the terminal boardi need to know what the volatges are during operation. I get for voltage at G is 24 VAC, Y .1 VAC, W .1 VAC, and R .1 VAC. Are these normal? Possible computer problem also?

When I check the voltage to the gas valve I read 0 VAC in testing mode, there's no clicking of the solenoid or is it enerigizing . When I disconnect the lead from the GSV valve I read 14-15 VAC on the lead from the computer. No load?
Does the computer inhibit the 24 VAC signal to the GSV since the pressure switch on the draft inducer motor does not close? I'm about to change the inducer motor, any suggestions or recommednations, thanks for your time, much appriciated.

Go Navy

We've had our furnace for quite a long time and had to replace the draft inducer fan a couple years ago when it had about the same symptoms as you describe.

Those fans just have oilite bushings (they run quieter than ball bearings) which eventually dry out and then the motor will start slowly and won't run fast enuf to create enough airflow and then the pressure switch(s) won't pass voltage to the control.

Before I discovered they were widely available over the internet either from discount HVAC supply places or over eBay, I paid over $200 from the
Dealer. Then I discovered I could have gotten the same thing for under $100 over eBay.

Thanks for your reply, I'm going t get a new draft inducer motor, again thank you!

Thanks much appriciated