My furnace is about 7 years old. I replaced the temp control board about 3-4 years ago. A couple of weeks a go, it would not come on. I found the wire to the ignitor had a bad connection. But, this problem existed before that, and is still happening. The furnac comes on and warms up normally. It then starts blowing and runs for about 5 minutes. It then shuts off for about 3-4 minutes then comes back on and finishes it's cycle. When it turns off, it has not reached the set temp.. but after coming on the second time, it reaches the set temp and turns off. What's up?
2007-02-15 04:16:39 · 6 answers · asked by aj1964 3 in Home & Garden ➔ Maintenance & Repairs
This problem started a few years after replacing the temp sensor board.
2007-02-15 05:52:38 · update #1
Part of this problem could be a very dirty air filter. Your burner comes up to temperature, then the blower kicks in. After a bit the stack overtemp sensor cuts off the burner because the stack s too hot. Meanwhile the blower keeps going, cooling things down. When the stack gets back down in the safe range, the burner kicks on again.
Otherwise the relay contacts on your control board may need burnishing. Also you may want to recheck your connections on the controller.
2007-02-15 04:36:11 · answer #1 · answered by KirksWorld 5 · 1⤊ 1⤋
it sounds like the blower moter is running on low speed.and is not able to disipate the heat generated by the burners .on the temp board that u replaced .look for the blower speeds on the board .blk is high blu .is med and red or orange is low speed try unpluging red and blu .see what happens if blower is faster then tape off the other two wires...
2007-02-15 13:31:20 · answer #2 · answered by ata31254 3 · 0⤊ 0⤋
Make sure filters are cleaned. To check if my thermostat had gone bad recently, i "hotwired" the wires that hook to the thermo directly together. The furnace lit properly and stayed lit until i unwired the wires. This told me that i needed a new thermo, they are relatively easy to replace yourself and you can pick them up almost anywhere, i got mine at Ace hardware.
Furnace works just fine now.
2007-02-15 13:44:13 · answer #3 · answered by kimmi_35 4 · 1⤊ 0⤋
Something is loading your blower motor when it starts. It is tripping it's internal overloads and shutting down. When the overloads cool off and reset the motor restarts. Could be a dry bearing on blower motor, bad start capacitor, faulty wiring, or a bad blower motor.
2007-02-15 15:28:01 · answer #4 · answered by magiccharm 5 · 1⤊ 0⤋
Check for dirt and dust in the thermostat. Especially if it's an older "mercury switch" type. Other than that you're probably going to be needing a new regulator unit soon.
2007-02-15 12:28:13 · answer #5 · answered by Ricky J. 6 · 1⤊ 1⤋
I'm going to say it's the thermostat being dirty. I had the exact same issue, cleaned it out and it was fine,
2007-02-15 14:49:22 · answer #6 · answered by hooty_hey 2 · 1⤊ 0⤋