The dreaded 5 amp fuse blowing.

Have a 20 year old Bryant heat pump the is blowing the fuse on indoor circuit board. Have replaced compressor contractor, both runs of stat wire, both indoor and outdoor boards, and reversing valve coil.

Today tried new thermostat. All with same result.

Unit will function with reversing valve orange wire disconnected (why I changed coil). But of course won’t go into defrost.

With fuse replaced unit will run 1 or 2 cycles and then blows fuse on shutdown. Sometimes it will quit in middle of cycle.

Have some experience in HVAC but close to giving up.

???

What suggestions does your service technician suggest?

Why have so many parts been blindly replaced with no troubleshooting?

My service technician suspected bad contractor and ended up with a very expensive $*** contractor. Next he said must be short in stat wire, so I jumped. New wire to outside with no result so did same to stat.Please leave pricing out of your posts. It is not allowed by forum rules.

Originally Posted by Reager

My service technician suspected bad contractor and ended up with a very expensive $20 contractor. Next he said must be short in stat wire, so I jumped. New wire to outside with no result so did same to stat.

Sounds like you need a new service technician. Check the contractor locator on the map here and see if someone’s close by that can be of assistance. Let us know how it works out.

Shorts can be easily found without changing random parts.

Seems like we have heard this story so many times before. The worst of it is when so many things are done with virtually no testing, possibly not even an educated guess, the original problem is taken care of but a new one takes its place so it looks like it will never get fixed.

That is an insane number of parts thrown at a fuse failure.

I have had several shorts that did his. It is tough to find sometimes.

I have NEVER thrown parts at the issue.

You seriously need a qualified tech, not a parts changer.

Trane had a similar problem with their BWR models. Check the reversing valve solenoid coil wires. You may find that they are touching the hot gas discharge line. The only time it will blow the fuse when it is in air conditioning or in heating during defrost. I almost bet money that that is the problem

The forum rules are clear in that we can not assist with DIY troubleshooting and repairs of homeowners systems.

You need to reach out to a another contractor to investigate.

Any more questions on how to find this issue will results in this thread being closed.

Yeah, I should have said get a knowledgeable tech to look at the wires. Sorry.