Furnace / AC / Air Exchanger Problem?

[Triphammer]

When did the problem start? Gas furnace or heat pump W/ auxiliary electric heat coils.
Changing T-stats won't tell you if there's a problem w/ the "Fan On' switch, it's in the sub-base. You will need to disconnect the green wire from the "G" terminal on the sub-base. If it's a heat pump w/ auxilary electric coils, they'll usually use "ThermoDisk"TM relays. If it started after a test run of the heat, the Thermo-Disk may have stuck. They'll sometimes do that after sitting for the summer. If it just developed on it own, the "FAn Delay-Off" relay may be going out. It's a little electronis control that keeps the fan on for a minute or so to raise the efficiancy rating of the unit by removing the last bit of cooling from the evaporator coil after the compressor stops. Staing off after shutting of the breaker then resuming after going throught the T-stat cycles sounds more like a faulty fan delay -off relay.

[AZRedhawk44]

OK... this is just weird...

So the heat creeped back up in the last week to where I wanted to turn on the bedroom AC unit.

I flipped it on and I got exceptionally warm air from it.

"No problem," I figured. "Probably just hot air from the attic or just some ambient warm air from somewhere.  It'll cool in a minute or two."

I give it a few minutes.  It's blowing even hotter air.  I flip it off, wait for it to turn off, and listen as I turn it on again. 

I can hear the WHOOSH (scientific term ) of the heating element in the furnace turning on.  It's just now decided that heating when the thermostat is set to cool is a good idea.

I turned the bedroom AC unit off after this revelation and turned on the other zone for the living room.  That coolness still ended up filtering back to the bedrooms, so no big deal.

I tested it out again today:

I turned on the AC and went outside to the unit.  The unit is blowing noticeably cool air out of its top when you stand out there on a nice sunny 90 degree AZ day, and the air exchanger is blowing hot air through the ductwork that I suspect is actually getting heated by the furnace.

Awesome.  :-)  I'm so glad I bought a home warranty.

Anyone got any ideas as to what's up with it?

[280plus]

It's lost it's mind. 

Call somebody. Try the closest to you first and hoprfully they are a decent company.

[Brad Johnson]

Anyone got any ideas as to what's up with it?

Possessed, maybe?

Brad

[AZRedhawk44]

If it's a heat pump w/ auxilary electric coils, they'll usually use "ThermoDisk"TM relays. If it started after a test run of the heat, the Thermo-Disk may have stuck. They'll sometimes do that after sitting for the summer.

Just read the above.  Interesting.

Sounds like I need to get up in the attic soon.  Thanks, triphammer.

[280plus]

Is it a heat pump? With electric backup?

[280plus]

Noticeably cool air from the outdoor unit means it's running in heat mode. The whoosh sounds like the reversing valve cycling. We're talking some kind of control issue that really should be looked at by a "pro". All you have to do is find one.

Look for a local dealer for the brand you have. Check the brand's website.

[Jim147]

If it's a heat pump i go with 280plus on control problem. Going by the fan problem and now this.
I never rule out low voltage wire problems until they get check.

Not much help but this is one of those need more info times.

jim

[Scout26]

Gremlins....

Or you let Fistful work on it .....   (Making it his fault)