Any HVAC experts out there?

[mashdar]

Where would a re-setable overload be located? I haven't found any fuses but quite possibly because I'm not looking in the right places.

Some compressors have a little reset button on the compressor itself.

But upon further thought, a tripped overload would not trip the breaker, so probably not the problem.

 

[mac_1103]

If you still have the caps, do a continuity test on them. Zero on a capacitance meter means it's shorted. On the other hand, if it read 0L, that means overload, which means infinite capacitance, which means OPEN ckt, which is what I would have expected. A cap that fails open will result in a motor that fails to start turning, aka stalled, which can result in overcurrent and failed windings, which results in a breaker that is tripping. LOL I've had a whole pot of coffee already today.

Zero, not 0L and passed continuity. Have another cup.

 

[whoaru99]

One could probably pretty easily disconnect the compressor and fan from the contactor and see if the breaker still trips. Guessing it won't then, but?

If no longer trips and depending how the connections are and or how much you care to temporarily rig up, one might then reconnect fan and compressor, one at a time, and isolate which is causing the breaker to trip.

 

[mac_1103]

Should have noticed this sooner, but the thing has a diagnostic module. It's flashing code 6, which is "Open start circuit." Of course, there are probably at least a dozen reasons why the start circuit might be open...

 

[mac_1103]

And the winner is... internal short in compressor windings.

 

[passedpawn]

$$$

 

[mac_1103]

$$$

Well yeah, but it's not going to kill me. Like I said we got 17 years out of this one. That's about 119 in dog years.

 

[passedpawn]

We get about exactly 10yrs out of a system down here. They run a lot more down here I'd imagine. We use heat pumps, so when it's cold we also get heat out of them. (well, not cold to you probably)

 

[mac_1103]

We use heat pumps, so when it's cold we also get heat out of them.

This is a heat pump. Don't know about you, but up here you need a solid supplemental heat system. Which in this case is an oil burner that is as old as the house (i.e., 1967).

I think we'll be able to keep the inside coil and just replace the outside unit.

 

[whoaru99]

You probably can, but I think the internal coil often isn't terribly expensive and on a older install might be wise to do. Possible too, it might be a warranty stipulation too if you're buying a new outside unit.

 

[mac_1103]

You probably can, but I think the internal coil often isn't terribly expensive and on a older install might be wise to do. Possible too, it might be a warranty stipulation too if you're buying a new outside unit.

The inside coil was not replaced when the current outside compressor was installed in 2007 and it wasn't a warranty stipulation then. It did subsequently develop a leak and was replaced about five years ago, which is why I thought it might be worth saving.

 

[passedpawn]

Evaporator coil inside the air handler is $3k replacement on my system. At some point they will corrode and leak refrigerant.

 

[passedpawn]

I would not replace a 5 yr old handler/evap coil or the copper lines to the compressor.

 

[mac_1103]

So they want $3300 to install a new compressor and $5500 if I want a new evaporator coil too. Guess I'll double check the age of the coil before I decide. I suppose I could get additional quotes, but these are the guys who installed my current systems and they were about $3000 less than anyone else on that job. I have a feeling they're still the cheapest local installer by far.

 

[passedpawn]

Consider: if they are "2 chucks and a truck" operation, then their warrantee is worthless. They will be on to roofing or lawn care by the time you call them back.

[edit] those prices are probably fair. At least, for a 5T system.

 

[mac_1103]

if they are "2 chucks and a truck" operation, then their warrantee is worthless.

Did you miss the part about them doing the previous install 17 years ago? Didn't have any problems with those ten year warranties. They've been in business here for over 30 years. The techs are all certified and average 25 years experience. And the owner coached my kid in middle school football.

 

[IslandLizard]

So they want $3300 to install a new compressor and $5500 if I want a new evaporator coil too. Guess I'll double check the age of the coil before I decide. I suppose I could get additional quotes, but these are the guys who installed my current systems and they were about $3000 less than anyone else on that job. I have a feeling they're still the cheapest local installer by far.

Perhaps consider buying and installing the new coil with the compressor. Then keep the old coil as a spare/backup?
The evap coil is likely aluminum copper, it may need to get flushed and capped or so to prevent corrosion while stored.

We had the evap coil on the heat pump replaced after merely 4 or 5 years of service, still under the system's original warranty, after it had sprung a tiny pinhole leak. They told me that coil would have run around $4000.

We were still out about a $1000 for several service calls, testing, dye injection, recharging, and stuff like that. The new one is still doing fine after 9 years. Let's hope I didn't just jinx it.

 

[whoaru99]

That seems like a lot for an evaporator coil, but maybe the heat pump aspect makes it cost more.

 

[passedpawn]

Did you miss the part about them doing the previous install 17 years ago? Didn't have any problems with those ten year warranties. They've been in business here for over 30 years. The techs are all certified and average 25 years experience. And the owner coached my kid in middle school football.

yes sorry.

 

[mac_1103]

That seems like a lot for an evaporator coil, but maybe the heat pump aspect makes it cost more.

I think it's the Rube Goldberg scheme that somebody used to modify the original oil heat system to add AC in the first place (sometime in the early 1990s before I owned the house). Replacing the coil takes a lot more labor than it would on my other zone, which has a proper modern air handler.

 

[mac_1103]

The evap coil is likely aluminum copper, it may need to get flushed and capped or so to prevent corrosion while stored.

The evaporator coil is aluminum. Replaced in June 2019 when the old copper one sprung a leak. So only about two months left on the warranty.

Perhaps consider buying and installing the new coil with the compressor. Then keep the old coil as a spare/backup?

Decided not to replace it until it fails since it doesn't affect the warranty for the new compressor unit.

 

[Clint Yeastwood]

This is a funny coincidence, because I post a lot of brewing questions on HVAC forums.

 

[passedpawn]

This is a funny coincidence, because I post a lot of brewing questions on HVAC forums.

 

[mac_1103]

The compressor motor was indeed dead. The funeral was held in May.