HELP house heater gone crazy.

[Jude Tuliszewski]

Came home opened my front door and thought I opened an oven door . Looked at the thermostat and the temp was 80, the temp was set for 70 . So I am thinking, OK the digital thermostat went wacky. I put the switch to the off position and nothing, the heater kept on cranking, so I am now scratching my head and thinking well heck that can’t be good . I had to flip off the breaker in the main house panel to get it to shut down. Next thing I try is to disconnect all 4 wires to the thermostat, still thinking (hoping) it is something wrong with the thermostat, and flip the breaker back on. Crap, it fired back up again, so now I am thinking it must be a relay of some sort, but I don’t see anything on the board that looks replaceable. So my question is, is there something else that I should be thinking about, or does it sound like I will need a new control board ($$$) . The unit (air handler) is made by Amana (BBC60A2A), it is straight cool with electric heat forced air central system (air handler inside compressor outside), not a heat pump. I'm just glad it is going to warm up alittle the weekend. Any help or insight will be greatly appreciated.

[Tom Hummel]

Jude,
did you try to disconnect the thermostat wires where they enter the heater? It is not uncommon to have a short somewhere in the wires between the stat and the air handler.

[Chuck Wintle]

Came home opened my front door and thought I opened an oven door . Looked at the thermostat and the temp was 80, the temp was set for 70 . So I am thinking, OK the digital thermostat went wacky. I put the switch to the off position and nothing, the heater kept on cranking, so I am now scratching my head and thinking well heck that can’t be good . I had to flip off the breaker in the main house panel to get it to shut down. Next thing I try is to disconnect all 4 wires to the thermostat, still thinking (hoping) it is something wrong with the thermostat, and flip the breaker back on. Crap, it fired back up again, so now I am thinking it must be a relay of some sort, but I don’t see anything on the board that looks replaceable. So my question is, is there something else that I should be thinking about, or does it sound like I will need a new control board ($$$) . The unit (air handler) is made by Amana (BBC60A2A), it is straight cool with electric heat forced air central system (air handler inside compressor outside), not a heat pump. I'm just glad it is going to warm up alittle the weekend. Any help or insight will be greatly appreciated.

Sounds to me, as you said, a relay somewhere. The relay could be a solid state device that has become short circuit.

[Joe Pelonio]

Mine is older, but when that happened about 8 years ago it was the control unit, which the thermostat wires connect to on the furnace. It was about $80 and easy to replace. I guess the newer ones are like cars, computers that require a lot of test equipment to diagnose and repair.

[Al Wasser]

That happened to my garage heater in the middle of the summer. I had to shut the gas off. The I replaced the thermostat and all was well again.

[Jude Tuliszewski]

Thanks for the replies so far.

Tom: No, I will give it a try, but the air handler is only on the other side of the wall from the thermostat, so only about 3 feet of wire, but like I said I will give it a try as it would be nice if it was something that simple (read cheap).

Charles: That is what I was expecting but it has a circuit board controller and I cannot see anything on it that looks replaceable. I guess I am looking for more of a confirmation of what I think is the logical part gone bad, and too see if there is anything else I might not have thought of to check before replacing the board, as I am not overly A/C savvy.

Joe: I looked around and the first price I found was $297 and change. Then the very next one I looked at was an OEM Amana board, and was only $68 , but would take 12 to 14 days to ship, go figure on the price difference. I will look around locally on Monday and see what I can find that I can pick up.

Al: Thanks for the input, but I completely disconnected the wires on the thermostat and when I flipped the breaker back on it immediately kicked back on. I have all but ruled out the thermostat, but like I mentioned above I will try what Tom suggested, ya just never know I might get lucky.

ac board.jpg

Oh, the things under the white plugs that are on the left side of the board are soldered to the board, just a way to transition from the big plugs down to the board.

Again, any input or advice will be greatly appreciated.