I have a RUUD 90 plus gas furnace that has been working OK. Last night I turned down the thermostat to 70 degrees. This AM turned up to 78. Furnace did not turn on. Turning on the fan only the fan does not run. 2 green lights on, one flashes 2x.
If you reset the furnace power does the system start at all? I think a 2 flash might be caused by the pressure switch stuck open. The exhaust motor should run on a call for heat.
Have you made sure there is no snow covering the vent pipes that connect to the furnace and go outside?
I removed the front covers and while holding in the interlock switch both green lights come on. After a couple of seconds one green light flashes and I hear a relay pick The small blower motor hums. It does not turn.
Before my first post the blower motor was making a sound like it was trying to turn as if a phase of the power was missing (?) The motor casing got very warm. Now it only hums.
By tapping on the motor casing I was able to get it turning again but it makes a noise like motor shaft is binding with something wthin the whole blower assembly.
So are both the ventor motor and main furnace motor humming?
It sounds like the exhaust motor (the smaller motor above the main blower), is seized. That would cause a 2 flash lockout, as the ventor motor is not running and closing the pressure switch.
You may need to replace the ventor motor assembly.
It sounds like the smaller blower motor is my problem. Any idea the cost for a blower motor is and how long will it take to replace?
I think your furnace model is UGJD and the ventor motor is part #70-24157-03. You're probably looking at $100 - $200 for the part and 1 hour labor to replace it.
I have what looks to be a UGRB model 70625942. The furnace/heat pump is 8 yrs old. The last couple of years we've been running in bypass mode. What is a good thermostat?
You'll need a Fasco motor part #7062-5942.
Nest makes a decent dual fuel thermostat that will control the furnace and heat pump.
Thank you!