Home AC Emergency help, PLEASE

911SC Pilot · 07-12-2003, 07:48 AM

I know this isnt the right form, but Im hoping somebody on this form knows.

My moms house`s power went off on friday sometime. The Home AC unit was running when the power went off. With this unit, I guess when the power goes off, you have to go up on the roof and hit a reset button on the AC unit. How do I do this process. My father would do it, but never told myself, or my mom, how to reset it before he died last year. I know on the thermostat in the house has a reset position on the Cool/ Heat switch.Do I use that ? I tried to reset it yesterday, the compresser came on, but then shut off, only leaving the fan running. I really need help with the correct process of reseting the unit. DO I cut the power off to the house to reset it. Do I cut the power at the AC unit on the roof. Do I push the reset button when the unit is On ??? Its just going to be 119 in vegas for the next week, and I dont want my mom to get hurt from the heat in the house. Sorry Wayne for posting this here, I just felt I would get a better responce on this form, thanks.

rfng · 07-12-2003, 07:55 AM

If its a roof air, there should be a seperate breaker box next the to unit. You need to go up on the roof and flip the breaker. You might need new fuses but you wont know until you go up.

911SC Pilot · 07-12-2003, 07:59 AM

Yes, its a roof unit. There is a breaker switch on the side of the unit.Do i flip the breaker while the unit is running, or do I set the thermostat in the house to the reset position ? When Do I push the reset button? When the breaker is off, or after I turn the breaker back On ?

rfng · 07-12-2003, 08:02 AM

No you should have the unit off. Then go up onto the roof and flip the breaker. There should be a couple of pretty good size fuses. You might need new ones if the unit get no power after you flip them.

rfng · 07-12-2003, 08:04 AM

Then you go back down and turn the unit on. If it keeps poping the breaker the fuses might be weak or the breaker unit requiring a new circuit or fuse.

911SC Pilot · 07-12-2003, 08:06 AM

Well, I have power, so I think the fuses are fine. I did that yesterday, I turned the unit off at the thermostat, went up on the roof, flipped the breaker off, flipped it back on, pushed the rest button, went back in the house, and turned the unit on. The compresser kicked on, but then shut off 30 seconds later, yet, the fan was still on.

911SC Pilot · 07-12-2003, 08:07 AM

Awww, could be a fuse problem. If so, why would the fan still run, but not the compressor ? Should I wait 3 to 5 mins when i flip the breaker, before I flip it back on again ?

rfng · 07-12-2003, 08:09 AM

Then there a problem with the unit and you need to get an air guy out there or electrician as either the unit has a problem or the breaker circuit is weak after the many year of use and needs to be replaced.

911SC Pilot · 07-12-2003, 08:13 AM

That sucks. It was working fine friday morning. Until the power went off. This has happened in the past, and my father would go up and hit the reset button, and would be fine. I wish I knew what process he used.

911SC Pilot · 07-12-2003, 08:17 AM

Well, Im going down to moms, to see if the I can rest it again. My last question. When do I hit the reset button, after i flip the breaker off? Or do I shut the breaker off, let it sit for 3 to 5 mins, then flip the breaker back on , then hit the reset.?

autobonrun · autobonrun's Garage

My home A/C has a timer that doesn't allow the compressor to run for a few minutes if the power goes off. This prevents potential damage from brief power spikes. The blower in the house will still run however. This sounds like what you are seeing.

If there is power from the thermostat in the house out to the electronics at the compressor unit, that means your thermostat in the house is good. I believe the signal from the thermostat in the house out to the timer is 24vdc. In my case, this past month, I had to replace my thermostat because it was not sending the signal out. Once that was replaced, I also found the timer at the compressor was bad. The timer is not expensive at all and can even be bypassed in the short term. If you have power on one side of the timer but it is not going to the other side after it times out, this would be the problem. If your problem is the thermostat control unit, replacement is simple. I think there are only 5 wires that need to be connected. Just check the colors and make sure they go on the correct screws.

It's not too difficult to troubleshoot if you have a voltmeter, a schematic of the unit, and an electrical background. Check your owners manual for a schematic. If you don't have an electrical background, just pay for the service call. There are some fairly high voltages that feed the compressor and a bad shock is not worth the money you might save.

Good luck.

911SC Pilot · 07-12-2003, 10:01 AM

Well, Looks like it worked. Took the thermostat setting, and placed it on the Off/Reset position. Climbed onto the roof, flipped the breaker to the off postion. Clicked the reset button, and let the breaker sit in the off postion for 5 minutes. Flipped the breaker back on, climbed off the roof, clicked the thermostat into the cool postion, and is now pumping 60deg air, and the compressor hasent shut off.

Another note. I didnt see 2 fuses in the breaker box. Just the on/off breaker switch and wires.

autobonrun · autobonrun's Garage

Quote:

Originally posted by 911SC Pilot
Well, Looks like it worked. Took the thermostat setting, and placed it on the Off/Reset position. Climbed onto the roof, flipped the breaker to the off postion. Clicked the reset button, and let the breaker sit in the off postion for 5 minutes. Flipped the breaker back on, climbed off the roof, clicked the thermostat into the cool postion, and is now pumping 60deg air, and the compressor hasent shut off.

Another note. I didnt see 2 fuses in the breaker box. Just the on/off breaker switch and wires.

That's good news. I'm positive the circuit was being held open by the timer rather than the breaker. Breakers reset immediately unless they have thermal overload protection which very few do. In that case, the thermal O/L has to cool off before it resets. By waiting five minutes, you just allowed the timer to go through its cycle. If you had shut it off again before it did, it would have reset and started the sequence all over.

911SC Pilot · 07-12-2003, 03:05 PM

Very good news. Thanks for your help.