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My 24 year old home A\C went out some time Sunday morning. I had a tech come out and look at it, and was told that the compressor is shorted to ground, and that this means I have to replace the entire compressor and possibly the entire system.

I'm asking this community for a sanity check, since I know nothing about HVAC systems. Is a "compressor shorted to ground" really a "replace the whole kit and kaboodle" situation? Or is more information needed to reach that conclusion?

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They want to replace the entire system - inside and out. – John Jun 11 '13 at 12:08
24 years - it's the original system put in when the townhome was built in 1989. So yes, I've known a full system replacement was coming, I was just hoping to squeak out a few more years before it got here... – John Jun 11 '13 at 12:39
The time has come, but don't feel so bad. You'll probably end up with a more efficient system, which will save you a bit in operating costs. – Tester101 Jun 11 '13 at 12:51
Just to answer your literal question, compressors are not field serviceable. If your compressor has a problem, the only option is to replace it. – longneck Jun 11 '13 at 14:40
Final result: the compressor is just fine. The first tech didn't bother to examine the whip, which was shorted phase-to-phase just as it exited the disconnect box. Roughly $350 later, everything is back in working order. (Yes, I'm still planning on a complete replacement in the next 3-5 years.) – John Jun 12 '13 at 11:12

The compressor is the "engine" of the AC system. It, and a few valves, and the condenser fan, comprise all the active portions. Everything else is passive. The compressor is an electrical motor connected to a precision pump. The pump has to be lubricated by sufficient refrigerant (Freon or substitutes). If a compressor seizes, it may burn out the electrical motor, causing the electrical windings to short out.

Long story short, a failed compressor may be a reason for system replacement. You would be well advised to get a second opinion from another contractor. Get quotes for both repair and replacement.

Another reason to replace the system, is the mandated phase-out of R22 refrigerant. If your system is older than 5 years, it probably uses R22. While an existing unit doesn't need to be replaced, per se, because of the phase out, practically, it will, due to the price of the refrigerant. I just paid $5/ounce for my system recharge.

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It's 24 years old, and yes it does use that horrendously expensive R22 refrigerant. I'm not looking forward to paying $11k (the first quote of at least 3 I'll be getting) for a new 3 ton system... – John Jun 11 '13 at 12:10
At that price, you may want to look at a geothermal heat pump (with ground sourcing). The install costs are high, but operating costs are usually much lower. Look here: qualitysmith.com/request/articles/articles-hvac/… – HerrBag Jun 11 '13 at 12:28
Geothermal probably isn't a viable option for me since I'm in a townhome, not a single-family. The HOA might not like that idea. – John Jun 11 '13 at 12:43
In that case, pitch it as a high efficiency upgrade for all the units. Common wells are possible, though not universally acclaimed over individual wells. You'd need an experienced contractor/HVAC design firm to make the pitch/proposal. Joint system maintenance would get rolled into the annual maintenance fee. Just sayin... – HerrBag Jun 11 '13 at 13:04

If the compressor is measured at the compressor connector pins under the connector cover with the conductors (wires) removed and any point reads to ground or any resistance less than infinity, the compressor is fried, dead, gone.

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Language? It's the correct kind. – Mazura Jul 22 '15 at 20:37

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