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+-- Thread: Weird Heat Pump Issue (/showthread.php?tid=7338243)
Weird Heat Pump Issue - rwe2156 - 03-19-2018
Noticed blowing cold air when on HEAT.
When this happens, the condenser (outside) is not running (comperssor or fan), "heat on" not lit up on thermostate & emergency heat not on. Cannot turn air handler off without throwing breaker.
Had the thermostat replaced. About a week later, its doing it again.
He came back and corrected some wiring in the therm and aux heat was working.
Well, about another week later, the unit is blowing cool air. Same thing - condensor not running, "heat on" is not showing on thermostate. However, this time, I found if I turn the fan to "auto" and back to "on" it seems to reset immediately and everything works.
I remember once years ago I had a unit with a bad board causing it to go into defrost mode.
I'm not getting a response from my AC guy. I think he's maybe at a loss and is embarrased to call me back?
Any ideas???
RE: Weird Heat Pump Issue - EricU - 03-19-2018
it certainly seems like a control issue to me.
RE: Weird Heat Pump Issue - daddo - 03-19-2018
"I found if I turn the fan to "auto" and back to "on" it seems to reset immediately and everything works."
Why are you running the blower 24/7? If you have old ducts running through a cold space/attic, they will begin blowing cooler air if the system is off for a while. Try it in "auto" mode. It shouldn't, however, make any difference in the heat or cool cycling.
First check the batteries in the thermostat- weak batteries make thermostats do strange things we can't explain.
What type thermostat?
RE: Weird Heat Pump Issue - rwe2156 - 03-21-2018
(03-19-2018, 06:13 PM)daddo Wrote: "I found if I turn the fan to "auto" and back to "on" it seems to reset immediately and everything works."
Why are you running the blower 24/7? If you have old ducts running through a cold space/attic, they will begin blowing cooler air if the system is off for a while. Try it in "auto" mode. It shouldn't, however, make any difference in the heat or cool cycling.
First check the batteries in the thermostat- weak batteries make thermostats do strange things we can't explain.
What type thermostat?
Sorry I meant to say turn to "on" then back to "auto".
The thermostat is brand new. Honeywell.
RE: Weird Heat Pump Issue - Robert Adams - 03-21-2018
Let's see. Worked fine for however long then started this issue. Replaced thermostat and it's now happening again. Through deduction that leads to the most likely culprit being the control board in the air handler.
Lots of electronic board issues these days because of ROHS and having to use lead free solder which leads to poor connections and very poor durability. Unfortunately the only exceptions to ROHS is transportation as you can't have a computer in a car, plane,boat fail because of poor quality solder and other components. Hopefully ROHS will go away and be replaced by the other standards which are much more realistic.