Heat Pump Contamination

So maybe two months ago we had an issue with our heat pump. We had the company who designed and installed the system (and the only ones who have ever touched it) come out and repair it. Then last week the compressor blew up. We had a different company come out and they said our system has a lot of black debris in the coolant lines which lead to a compressor failure.

So how does an enclosed system get contaminated? The second contractor said it "could" be due to a repair yet he was unwilling to toss the first company under the buss.

Oddly enough our neighbors had the exact thing happen to them. Company A came out for a repair and then a few weeks later their system blew.

The repair estimates are about $4k. I know nothing about heat pumps so I am turning to the most worldly people I know of, GRM. Was my system intentionally contaminated?

Thank you for your time and thoughts.

Are they sure they aren't confusing the cause for a symptom? I'm thinking the debris could be the compressor's guts.

Huh. I never thought of that. Great point.

If they refilled their freon tanks (which they are not supposed to do) with "wet" compressed air, the tanks can rust on the inside (with disastrous results, including potentially exploding freon tanks).

How old is the system? Most name-brand stuff carries a pretty lengthy compressor warranty. I'd be talking to the company that did the service and the install.

Anecdote: Before we sold my wife's house, we had some Freon charged to the system which was about 15 years old. It cooled better, but the compressor blew up inside of a year.

It is a Lennox system. I have spoken to the first company. Lets just say my trust in them is completely broken which is why I am posting. I need to learn more about how these things work.

The system is seven years old.

Thanks again.

Unfortunately, just about anything is possible. $4K for a compressor replacement sounds kind of strong. Depending on size, I would think a new unit would be in the $5K-$6K range. I got a quote for a 3 ton for $5600 installed, and can buy the unit for about $2800. Link.

Yea I don't know our system's capacity but the unit is about 4' tall and 3'x3' wide. We have a lot of volume to heat.

In reply to Sultan:

The size of the case is (mostly) irrelevant.

The tonnage is written on the data plate, though sometimes in code (inside the model number), which is easy to Google.