Dearest hive:
my heat pump(2.5 ton coleman, 2015 or so install) is not making heat. We haven't used AC since mid august so it's been dormant a couple months. Turned on heat, house not getting warm, furnace fan doesn't stop. A couple years ago I had to replace the control board in the outdoor unit.
the fan on the heat pump is running, but it sounds like the compressor is not kicking on. Definitely just have fan noise at the outdoor unit and no low hum of the compressor and the lines are not changing temps. Every couple minutes for about 3 seconds I get a buzz in the outdoor unit.
hvac was never my specialty. I gather an internal component has failed and I will need to replace it, but how do I figure out which one?
Sounds like a capacitor for the compressor has puked and the compressor is cycling against the thermal overload switch.
Could also be the contactor.
The compressor could also be locked up.
Figuring out which one is going to require testing. I'd start with the contactor. Test for voltage on both sides of it. If it has voltage and the compressor isn't running I'd go to step two below. If it doesn't the problem is with either the control circuit or the contactor itself.
Then I'd move to the capacitor. There will be numbers on the side of it. Look it up on Amazon. They are about $15. Replace it.
Edit. Make sure you power the system down and ground out the capacitor before messing with it. They can hold a charge for a while and zap the crap out of you.
Thanks for the flow chart. Thankfully the plumbing and electric supply house i have an account at is right up the street and a massive hvac supplier also so most stuff i can probably have in my hands in 10 minutes
Since the fan on the outside unit is running, that tends to point to the capacitor. The contactor supplies power to both the compressor and fan when it closes. Usually, a failed contactor will present as neither fan nor compressor running which isn't the case here.
I'd bet you need a capacitor. Make sure the replacement matches the microfarrad rating on the original. There's three terminals on them which are usually labeled with "h" "f" and "c", hermetic, fan, and common. Make sure to get the proper wires on the proper terminal. Just swapping them over one at a time is the safest bet.
I usually tell people to buy an extra capacitor and keep it on hand. More times than not, it will save the day and get a guy back up and running quickly and avoid a trip to the supply house or a weekend crisis. Spend the money on USA made capacitors. They will have a prominent flag printed on the box. They really are better and worth the added dollars.
In reply to Cousin_Eddie (Forum Supporter) :
Yeah i was about to ask if a failed cap with 3 terminals could show as a fan works/compressor doesn't situation.
going to see what they have up the street soon, got a pic of the label to take with me
