AC will not turn off.

[OswegoLion]

I have 2 AC's and the one in the bedroom will not turn off unless I hit the breaker. It doesn't blow air but it runs even if temperature is reached and the off setting doesn't turn it off either. What should I do?

[Bama Rambler]

Are you saying that the compressor is running, but the fan shuts off?

If so, you most likely have either a bad thermostat or control board.

It would help if we knew what unit and thermostat you have.

[Bluepill]

1. If it is a digital thermostat, disconnect the power wire (usually red) for 10 minutes to reboot the microprocessor. Then reconnect and see if problem is solved.

2. If above doesn't work, disconnect the compressor control wire at the thermostat (usually yellow) and see if that shuts off the compressor. If so, probably a bad thermostat.

[CWG]

Did you find out what was causing your problem with your bedroom AC? Mine is now doing the exact same thing with the bedroom AC.

[Bama Rambler]

CWG -- The OP shows online, but hasn't responded to our request for info. So, either they've gotten it fixed and aren't interested in letting us know, or they've lost connection with this thread.

Tell us which A/C unit and thermostat you have and maybe we can help.

If you have a newer dometic digital thermostat, you may be able to initialize it and get it back working.

P.S. You could try PMing the OP and see if they'll respond.

[CWG]

Hi Bama Rambler,

I have the newer dometic thermostat and dual roof AC units. Any advise would be appreciated.

Thank you

[Bama Rambler]

There's an initialization sequence in the manual for resetting it.

But, here is the snippet of it.

To do a system reset:
• Make sure the CCC 2 thermostat is in the OFF mode.
• Simultaneously press the MODE and ZONE buttons. The LCD will display “IniT” and all available zones.
• Release the MODE and ZONE buttons.
• Press the ON/OFF button to exit system set up.

Make sure the unit displays both zones when it's initializing. If it doesn't, there's a communication problem with the zone that's not displayed.

[CWG]

Thank you Bama Rambler,

I just gave it a try as you suggested and still no change. AC and fan both run good but I can only shut them down by switching off the breaker.

Regards

[Randyman64]

"I have 2 AC's and the one in the bedroom will not turn off unless I hit the breaker. It doesn't blow air but it runs even if temperature is reached and the off setting doesn't turn it off either. What should I do?"

Is it the compressor or the fan?

The reason I ask is you can set the fan to run independently from A/C operation, even with the furnace on.

Check this:
From the control panel select the zone the bedroom is on.

Go to fan and see if it is set to auto/high or low.

Anything other than auto will keep the fan running all the time even if the set point has been reached.

You have independent control of both set of fans in zone 1 and zone 2.

Also note that when the unit is approaching set point on auto, it will slow down the fan speed. When it does, it will cycle off the fan for 3-5 seconds and then restart on the lower speed.

Hope this helps.....

[Bama Rambler]

If it isn't as Randy suggested, it sounds like you have a thermostat and/or control box issue.

[CWG]

Well that did not work, so I have an appointment for the dealer to have a look at it. Thank you for the suggestions.

[SeaDog]

It would seem to me that the unit has a suck or fried relay keeping the unit in the running mode until power is removed.

[CWG]

I agree SeaDog that it is down to the relay now. As long as it is repaired by Nov. before we start our migration south!!!

Thank you for the suggestions.