I have central AC and Heat. The unit is Rheem..model number is unknown at this moment. We turn it on, it warms up, reaches the desired temp, and kicks off. When the temp drops and it's time for the heater to kick back on, it blows only cold air so then we have to go and turn it off and then back on. After we do that, it will blow hot air again but only until it reaches the desired temp in the house and then we have to start all over again. I have heard a lot about thermocouplers but my husband went up there and said he didn't see one on the unit. So what could it be?? I am hoping it is something we can fix ourselves. Any help would be so much appreciated. Thanks!!
2007-12-29 14:02:00 · 5 answers · asked by YouSaidWhat??? 3 in Home & Garden ➔ Maintenance & Repairs
The unit is old...over 10 years for sure.
2007-12-29 22:00:24 · update #1
Does the furnace have any indicator lights on it? Many newer electronic controlled furnaces have diagnostic lights on them that will flash an error code.
If you can observe the unit when it does this it would help out a lot. Does the draft inducer power up, ignitor receive power, burner light even for a few seconds?
While circuit boards do go bad it really is not that common. It is most likely a bad flame sensor, pressure switch or even a limit switch problem. If you have the diagnostic lights the furnace will be able to tell you what is wrong.
If all else fails hire a tech to troubleshoot and then you will know what part to replace.
2007-12-29 15:45:01 · answer #1 · answered by mike b 5 · 0⤊ 0⤋
Is ther a cap on your chimney if not a bird may have fallen in the flue pipe and got stuck and is blocking the draft - pressure switch. The pressure switch indues a draft up the chimney and if blocked it will not always start... check and clean the furnace thourghly.... but I would disassemble the chimney or flue pipe and check there first. Low air flow when the switch is turned on for a moment will also indicate a blocked chimney. be sure to reassemble flue pipe completely - if you don't carbon monoxide could enter the house.
2007-12-30 00:09:32 · answer #2 · answered by Lamont 2 · 0⤊ 0⤋
The thermocouple won't be the culprit this time. (If you even have one.)
My guess is that the pc control board has gone out. Without testing, it's impossible to say for sure.
2007-12-29 22:09:16 · answer #3 · answered by Kurtis G 4 · 4⤊ 1⤋
sounds like its the pc board.and everytime u turn it off you are reseting the board
2007-12-29 23:28:46 · answer #4 · answered by john c 3 · 0⤊ 1⤋
call a furnace guy. its less of a headache on you and your other. it may seem like alot, but isnt your life worth it?
2007-12-29 22:11:30 · answer #5 · answered by knowitall 4 · 0⤊ 3⤋