Electrical issue HVAC
 

This has been going oin for two years.

My AC works fine and heater works fine. The issue is the transition from one to the other. If I run the AC during the day and switch to heat, all is well. If I switch from heat to AC, the outside unit trips the breaker. If I try to flip the breaker on, it just trips again. The only way I can go from heat to AC, is to turn the system OFF, flip the breaker on, then turn the system back on. So strange. Once I do this ONE TIME, the AC will cycle just fine every time. If I run the heater again, I have to repeat these steps.

Heater cycles fine
AC cycles fine
AC to heat, works fine
Heat to AC trips the breaker
Shut down, set breaker, restart...all good.

How old is the breaker? I have had them wear out.

Every breaker in the house is 14 years old. Why is it that is cycles just fine? Inrush current is the same at cycling as it is a start up.

Inrush clearly is not the same if it's tripping. Is there current from the heater still on the circuit that's not there when you do a recycle? Do you have flue dampers? The only other thing that I can think of is an issue with the HVAC itself. How does the capacitor look?

Capacitor is new-ish. Replaced last year. The start up process kicks on the blower, outside fan, and compressor. The cycle process kicks on the blower, outside fan, and the compressor. What else could be in the circuit in one case, that is not there in the other? Also, it is a gas heater.

Replace breaker if resetting service power switch doesn't work.

What happens if you reset the air handler breaker after turning off heat?
What happens if you reset the outside service switch after turning off the heat?

You didn't mention if the condenser has a heat pump.

I just had the breaker to my heat pump give up the ghost. Breakers get weak over the years. Takes less to make them trip.

No heat pump. No issue during heat or switch from AC to heat. Only heat to AC. For AC to heat, all I do is set the thermostat to heat and set the temp. If I do this going from heat to AC, the t-stat kicks the inside blower on, but the outside unit breaker trips. If I try to reset the breaker with the unit on AC and blower running, it will never reset. I have to turn the t-stat to "off", reset the breaker, then go back to the t-stat, set to "cool"and set the temp.

Head pressure in the coils, too much for comp to restart quickly into operating head pressures.....sounds to ME, there was a delay circuit in the control/stat? somehow to stop that, and it's not doing the job....allows outside comp to come on too fast.....

Y R U changing back/forth anyway??? we run overnight heat at say 72f in the house.....and we been opening windoze during the day.....except today it's much higher outside, but house is cool indoors yet, bright sunny day and over 90f in the atrium, but still only 72 in the house.....:dance:

I concur with the folks saying it sounds like a weak breaker in your control panel. Having said that, I wonder if installing one of those "hard start" units on your ac's would help? That would be treating the symptom, probably not the cause.

And also, I agree with Gene. I don't think I've ever used the a/c and heat together in the same day. Then again, for me, cheapness overshadows comfort. I would feel bad about paying to change the temperature I already paid to regulate the other way.

I also do the same thing Gene does, when it's temperate outside and not too humid, I'll open up some windows and just kind of ventilate the house. I do the same thing in May, when it's cool at night but hot in the day. I like to get the cool night air into the house, then shut the windows in the morning and capture the coolness, as it were. Makes it easier on the a/c.

Mid 60s at night and 80s in the day. I have a central unit to provide comfort at both times. That's what it's there for. :seasix:

Why would the head pressure be high after sitting inoperable all night? Also turning the system off and setting the breaker, doesn't change the head pressure.

Time to call an electrician. :yesnod:






























:leaving:

Is the condensing unit (outside) the only thing on the problem breaker circuit? (as it should be)

Yes.

I had thought you going from Heat to A/C or reverse.....and so doing it quickly wood trip up.......

but if NOT, and the system is relaxed before changeout......I DUNNO....

:dance::confused5:

BUTT there is one last guess......you have some gas flow valve that is not working right.....Y is another guess.....:issues:

If it cycles fine without popping breaker i doubt it's the breaker, almost sounds like furnace/thermo is sending wrong signal to me. It may be setup(thermo) as a heat pump instead of separate untis.
Migh t want to check model of thermostat and make sure it's compatible.