Heard a guy at the supply house say you should replace every capacitor when doing a compressor swap

I think that's overkill unless the cap is visibly bad or testing way out of spec, I've seen perfectly good caps run another 5 years after a swap. Anyone else just test them and leave the good ones in place?

2 comments

2 Comments

the_lisa1d agoMost Upvoted

Test them first for sure. Most of the time a cap that's still within 5% of its rating will last through the next swap no problem. Had a 370v run cap last 8 years on a system I put a compressor in, just left it alone and it still tested fine when the unit finally got replaced for a different reason. That said, check the common and fan caps too, sometimes they go out faster than the compressor caps.

nathan90123h ago

Buddy of mine learned this the hard way last summer @the_lisa. He swapped out a compressor on a Trane unit, tested the run cap and it was still within 3% so he left it in there. Two weeks later the fan cap went out completely, took the common cap with it when it shorted. Fried his new compressor too since the start winding kept running without the cap to balance it. Had to go back and replace all three caps plus another compressor. Now he just changes all three at once no matter what.