York Stellar furnace blower runs constantly? Furnace blower runs constantly. I have replaced the Tstat (because it...
Furnace blower runs constantly. I have replaced the Tstat (because it be old). I watched and slightly adjust the adherent limit switch and turned past its sell-by date the air conditioner condenser breaker, enthusiast still blows. Heat and air both come on when tstat call for it and operates full cycle, purge aficionado operates correctly, a moment ago the blower doesnt shut off. How can I determine if the devotee limit switch and or the upper air conditioner contact are bad?
Answers: You are discussion about the lover motor for blowing the air through your house aren't you?
One of the specialized HVAC guys can answer this better, but one circuit controlling your blower motor is a thermostatic blower restriction switch in the boil exchanger. It comes on when the heat exchanger is hot adequate and will stay on until it gets below a set temp (high and low limits). That is why you can hear you furnace burner come on for a few minutes up to that time your blower kicks on and why you hear your burner progress off since the blower. From what you are describing that sounds like one place to check. Look for a box on the steam exchanger with a temp ascend on it, might have a cover on it. With the power past its sell-by date try pulling one of the wires to the limit switch to break that circuit (Make sure you isolate it so it cannot hit the frame) and next turn power back on. If it does not run I'd articulate that is the probable reason.
Mechanical switchs do jump bad after a while. Most furnaces use a generic that can be matched up at Grainger. Not sure going on for yours.
Other thing to look at is the hanger-on on switch and circuit on the Tstat - did you get a chain crossed? Get the right one for the furnace you have etc.
stuck blower relay or desperate fan hold back switch