Heat pump compressor failures - twice within 30 days

[jollystomper]

First world problems... an inconvenience (eiven with a heatwave occurring) not a rant.

We have had 2 compressors on our heat pump failed within 30 days. The heat pump unit was installed brand new less than 6 years ago. The original compressor failed in July, and the dealer service replaced it (the part was under warranty, but the 5 year labor warranty had expired 6 months ago, so we still had to shell out $1200). The service tech said the failure was due to the motor seizing. We noticed that the circuit breaker for the compressor had flipped.

Less than thirty days later... the replacement compressor (which they told me was new and shipped from the manufacturer) failed in the exact same manner - motor seized up. We first noticed cooling not occurring, and checked the breaker. Sure enough, it had flipped again. The same service tech came out to diagnose it and was puzzled why the new compressor would fail in the exact same manner so quickly.

Now a 3rd compressor is being shipped and will be installed this week. In addition to the service tech from the dealer, a service tech from the manufacturer will also be there to see if they can figure out if something external might be causing the problem. They are not charging us for this replacement service.

So... in addition to being disappointed by the original compressor failing after less that six years (our previous heat pump lasted 15 years), I am surprised by the second one failing so soon after it was installed. It makes me kind of gun shy about this heat pump. We have a service contract with the dealer to perform regular preventive maintenance and tuneup twice a year. Th service tech who worked on both compressors says nothing external to the compressor caused the problem. The motor is sealed within the unit. No refrigerant leak, and the compressor is built to shut off if that that occurs. He did not see any issues with the power going to the unit.

My questions:

1) Has anyone else has=d this experience of heat pump or central A/C compressors failing so rapidly?
2)For those with HVAC experience or skills, are there other components in the heat pump installation that should be looked at?
[FONT=&quot]
[/FONT][FONT=&quot]At least this is happening early in my retirement.
[/FONT]

 

[Newventurer]

Have any neighbors experienced similar issues? Are you experiencing regular lightning strikes or electrical service brown-outs? Our prior home we installed a whole house circuit breaker that was supposed to protect against these type of issues. Hope the next one does the trick.

 

[GrayHare]

A design flaw could cause this sort of thing, but to confirm such you need a much larger sample size. Momentary electricity outages, such as power supply going off for a few seconds then back on, can be rough on a compressor. Do the lights in your home often flicker in that manner?

 

[Walt34]

In addition to what GrayHare mentioned:

This is a pretty long reach, but perhaps the power company is having issues with brownouts? When I was doing A/C tech work 45+ years ago that was an issue in some areas of the County where I worked. With the motors back then, as voltage dropped amperage draw rose and that would cause overheating. I'd think that probably has not changed. Also, one time here we had an overvoltage (the UPS warned me) from the power company, perhaps that could account for it too.

Otherwise I can't think of anything that would cause two seizures like that except design or manufacturing flaws. Or maybe just "ganging of tolerances" and you drew the short straw - i.e., bad luck.

 

[Bamaman]

I had to have an A coil out in my 3.5 ton Trane heat pump installed in 1996. I am almost embarrassed at.how much old Trane parts are if you can even find the parts. This was at my lake house so the a/c is.not used all the time.

Next fsilure, I am going to scrap the best pump and go mini split.heat pumps.

 

[jollystomper]

Thanks for the response so far!

From an electrical standpoint, we almost never experience brownouts or outages. Our lights flicker maybe once every few months. I have a couple of UPS monitors that report to my PCs, none of them recorded a power interrupt for the last month, and only 3 interrupts for a few seconds each over the prior 3 months.

The power to compressor is on its own circuit, but none of our circuits have had a problem. In fact, we have not lost any thing to an electrical surge for probably 10 years. Before that we would have several outages per summer (I think the utility company moved a couple of key lines underground and that made a difference).

According to the service tech, there was no sign on any type of surge, and he thought the compressor was designed to shut itself off if it detected too much electricity. But maybe that is why they are sending a manufacturer service tech out as well.

 

[hopefullyoneday]

Probably because manufacturers are getting greedier and wanting more profit so they outsource the original/replacement parts to the lowest bidder. I had a evap coil go out in mine after 6 years of use. Mine had a 10yr warranty on parts but only 5 on labor so it cost me about 900 to have it replaced. Lennox had a recall on the evap coil because it was made out of inferior metal and would rust out. The recall only covered the first 5 years of use parts and labor. The new Lennox coil they replaced it with only lasted 6 months before it failed. Unfortunately in today's world you cant buy anything that will last. But manufactures know we are a throw away/consumer society that will pay what we need to be comfortable. Hell you cant go buy a $2k tv today without them pressuring you into a ext. warranty that will guarantee it will last 2 yrs. Better get use to it as it is just gonna get worse.

 

[fireorbust]

Many HVAC techs are guessing at what caused a failure. Even the Factory guy may not be able to pin-point it. If the compressor is seized, it may have more to do with oil return due to original installation or cleanliness of the refrigeration system. I doubt that the problem is electrical. What is the first letter of the brand of heat pump?

 

[jollystomper]

What is the first letter of the brand of heat pump?

Oh, no reason for me to hide it... it is a Lennox system.

 

[jollystomper]

Probably because manufacturers are getting greedier and wanting more profit so they outsource the original/replacement parts to the lowest bidder. I had a evap coil go out in mine after 6 years of use. Mine had a 10yr warranty on parts but only 5 on labor so it cost me about 900 to have it replaced. Lennox had a recall on the evap coil because it was made out of inferior metal and would rust out. The recall only covered the first 5 years of use parts and labor. The new Lennox coil they replaced it with only lasted 6 months before it failed. Unfortunately in today's world you cant buy anything that will last. But manufactures know we are a throw away/consumer society that will pay what we need to be comfortable. Hell you cant go buy a $2k tv today without them pressuring you into a ext. warranty that will guarantee it will last 2 yrs. Better get use to it as it is just gonna get worse.

Unfortunately I think you are right. It is sad. When we moved in the house the heat pump was the original for the house was 12 years old, we got another 6 out of it. The next system lasted 16 years. The way this is acting up we'll be lucky to get 10...

 

[fireorbust]

Oh, no reason for me to hide it... it is a Lennox system.

Okay...

The factory rep will know of any "known" Lennox issues with compressors and such. They DO NOT want any bad press. Tell Lennox you feel they should replace the system and the dealer should kickin the labor. Check for "greenish" oil in the system.

manufactures have a pattern of sending out replacement components that will fail in the exact same manner as the OEM part. Once they finally catch on to the failure rate, they come up with a "better" solution. Lennox should step up and so should the dealer.

Also remember that heat pumps run all year around. normal A/c units only run during the summer. A 10 year old heat pump is like a 20 year old A/C condenser.

 

[samclem]

If the compressor is seized, it may have more to do with oil return due to original installation or cleanliness of the refrigeration system. I doubt that the problem is electrical. What is the first letter of the brand of heat pump?

+1. Assuming that you went from R22 refrigerant to R410 when you had the first unit replaced 6.5 years ago, did they install a new line set at that time? The line set is/are the two copper lines (one big, one small) that go from the outside unit to your inside evaporator coil. The oil in the old R22 systems is not compatible with the new R410 systems, and will destroy them. Some installers "clean the lines out" with a substance that is supposed to neutralize the old lubricants, but this is not a good practice. There are other things that can happen during installation that can kill a compressor: For example, if the lines are brazed without using a dry nitrogen flush in the lines, the resulting oxidation/soot inside the lines can eventually kill the compressor. Also, failure to thoroughly evacuate the system (down to 500 microns) leaves air, water vapor and other "incompressible" or "uncondensable" gasses in the system that can reduce the life of the compressor.

Installation problems can kill the best equipment.

 

[Just_Steve]

Could be a bad expansion valve causing a flooded compressor? As stated above non-compressible will kill a compressor in a heartbeat.

 

[Telly]

Could be a bad expansion valve causing a flooded compressor? As stated above non-compressible will kill a compressor in a heartbeat.

Yes, a Reciprocating compressor is subject to failure by slugging, but to my knowledge, a Scroll compressor is not, due to movement between the scrolls.
I wonder about system cleanliness AFTER the first compressor failure... any bits of shrapnel that work loose and travel later. The #1 cause of replacement compressor failures in vehicles.
On residential A/C, it is common to have a filter/drier on the liquid side, but if the filter used in the original build sprung when the compressor failed, bits would propagate on. A big suction-side filter would catch them, but they are rare.
Heat pumps have those changeover valves, they could be a problem with trash, besides TXVs.
To me, a compressor seizure is a big deal... Replace the evaporator, condenser coils, TXV, flush or replace line set, etc. etc. ?? It would be like a new system!
(please note that my use of "evaporator" means the inside coil, "condenser" meaning outdoor coil, as they reverse function in a heat pump in heating mode ).

 

[Just_Steve]

Yes, a Reciprocating compressor is subject to failure by slugging, but to my knowledge, a Scroll compressor is not, due to movement between the scrolls.

Good point, I didn't think scroll as all my experience has been with reciprocating.

 

[jollystomper]

Update: the technicians spent most of the day here, going over the heat pump, components, lines, connections, etc. They were on the phone with Lennox a lot.

The bottom line: no one has any idea why the second one failed, beyond just being a bad component. No issues regarding refrigerant (it had been drained and reloaded before the compressor had been put on, as well as when the original compressor had been installed), electrical connectors (they said it should detect surges and and shut down, and no evidence of a surge occurring). There seemed to be an question about the capacitor size - the Lennox folks on the phone said they expected a 50 ohm capacitor for the compressor, but the compressor documentation and on the compressor itself said 30 ohms, so the Lennox folks said "oh, OK". Beyond that, no one has a clue why the replacement should have failed for quickly.

They have installed a new compressor. Here is a summary from the work order of what they did:

- In Warranty Compressor Replacement
- Evacuate A/C or Heat Pump System - Up to 5 Tons
- Recover Refrigerant - Up to 5-Tons (Remove and Recycle Refrigerant Per EPA Requirement in Order to Perform Repairs on the Refrigerant Circuit)
- Weigh In Type R410-A Refrigerant - Up to 5-Ton System (Replace Complete Refrigerant Charge in System Containing No Refrigerant Due to Leak or Component Replacement)

So far no issues, but I will be nervous about it for a while.

 

[RobbieB]

I replaced my 3.5 ton central AC which is a traditional inside / outside ducted combo unit with with furnace and the lines were reused. It was a r22 to 410 conversion of course.

Done in 2010, no problems.

 

[JPatrick]

Oh, no reason for me to hide it... it is a Lennox system.

Now that you mentioned the brand, our Lennox heat pump has provided us with two failed motors over a 11 year period. Not a brand I would buy again.

 

[fireorbust]

There seemed to be an question about the capacitor size - the Lennox folks on the phone said they expected a 50 ohm capacitor for the compressor, but the compressor documentation and on the compressor itself said 30 ohms

The wrong capacitor may be the cause. The capacitor needs to be the correct rating (+/- 10%). They are rated in Micro-farads (not ohms). If they had a 50 on it originally and it should have been a 30, they may have destroyed the compressor motor windings. It would act as a "locked up" compressor, but a good tech should have been able to determine damaged windings with an accurate ohm-meter. My guess is that with the correct capacitor, you'll be ok.

 

[stephenson]

I'm thinking random failure on the first one - or some blockage or low oil issue, acid buildup, then an incomplete evacuation and purge on the replacement with the same blockage issue still existing. Replacement of the filter drier core? Right quantity and type of oil replaced after the purge?

Bottom line - if the replacement was a new compressor, I think it was the installation, not the compressor.

 

[jollystomper]

Update: Oh Please No Please No Please No...

We were fine through most of the Labor Day weekend. Then... I come back home late Monday afternoon around 4PM, and the house feels a little warm and muggy... check the thermostat (which has not been touch since the electricians left it), the house is about 8 degrees warmer than what the thermostat is set at. And room temperature air is coming out of the vents. Oh cr*p, I do not believe this...

I leave the dealer a message saying the symptoms that led to the previous failures are back again.

But then... I'm down in my basement man-cave, and around 10PM DW comes down and tells me did I do anything, because things have gotten cooler, even though the evening is still warm and muggy. I check again, the the house temperature is falling back to the thermostat setting, and cool air is coming out of the vents. DW says she noticed that the system seemed to turn off (as it does when the set temperature is reached), then came back on.

Since that time it has been operating normally. VERY fortunate as it will be very muggy with a 100+ heat index the next several days. The dealer is still sending a technician over today to check things out and see if they can figure out any additional clues as to what might be going on.

 

[Just_Steve]

This past July, 4 I had an issue where anything running 220v was not working including the A/C, turned out I had a bad neutral coming into the house causing low voltage on one leg. It was an intermittent problem but it was discovered before any damage to the A/C system. Power company came right out and changed out wires from pole to house. Maybe you should monitor your line voltage on both legs. Something like that can cook your compressor.