Replacing AC capacitor & contactor every five years (furnace, AC, heating)

[Shet]

I live in New Jersey and have a split AC (and furnace) system. Mine is builder grade brand I believe called ICP. I came across an article of Family Handyman yesterday where they suggested to replace the capacitor and contactor in the exterior condenser/compressor unit every five years or so.


Is this worth doing this at 5 years intervals as preventive maintenance?


Is there any other such preventive maintenance tip when it comes to split systems?

[chet everett]

Bluntly, that is NUTTY. Capacitors are generally designed to have a lifespan of 20 years. If a device is causing them to fail at 4x that rate the device is flawed. Maybe whoever wrote that suggestion has particularly crummy electrical service, with lots of brown-outs -- low voltage puts strain on capacitors. I suppose if the motor driving the compressor is barely able to overcome the "starting surge" that too would strain capacitors -- make sure the unit is built with sufficient capacity for the climate you will be installing it in. Capacitors can fail early when they are subjected to over heating -- makes sense to clean the unit at least annually and be sure it is located in area where airflow is sufficient to avoid excessive heat build up.


http://www.apqpower.com/assets/files...Capacitors.pdf


I would almost say that a junky split system with an old fashioned elctro-mechanical contactor (which relies on the same principle old time wild west telegraphs were based on...) you should consider a more reputable manufacturer that uses solid state controls. There are also firms that will sell an aftermarket kit -- https://www.supplyhouse.com/Ranco-49...sor-Contactors

[Zippyman]

I'd disagree with Chet about the capacitors, just based on my own experience - five years is about all I get out of capacitors. I've never lost a contactor though. As long as they're not ridiculously overpriced (they're normally a $35-50 part), I'd have them replaced before failure & keep the old one on a shelf, hopefully as part of an inexpensive maintenance call, where charge levels are checked, etc.

I have replaced contactors when you could see obvious pitting in the contacts. I'm pretty certain that takes much more than five years to appear on average.

I *wouldnt* pay say $200 in the off season to have a working capacitor changed - that's all it costs in peak season.

As for electro-mechanical contactors, they're still used & quite durable.. No need to reinvent the wheel.

[kevink1955]

Capacitors used to last the life of the unit but since PCB has been outlawed and most are now manufactured in China we are now seeing some fail at 2 years. Since the capacitor is what gives the compressor it's starting twist (electrical phase shift) it may not be a bad idea to put them on a schedule for replacment.


The harder it is for the compressor to start the more of a chance for an early failure.

[burr]

maybe the most common fix down here as ants are attracted to this power supply and ruin/plug up the contactors. until ants are gone, they will find.

[TrapperL]

ICP is a cheap Carrier HVAC system. For that reason alone I'd be replacing the entire unit. Not sure which is worse, Carrier or Goodman but both are cheap junk. The question of replacing any parts before they fail is kinda dumb. The units we use, Trane, American Standard, or Ruud do not have any kind of failures in at least the first 10 years. Most often the capacitor will last as long as the units which we figure to be about 20 years.

[mathjak107]

i have seen very few caps go bad in the field . most of the time the caps that were changed were mis-diagnosed. the only caps i have seen go bad regularly are the ones in vfd's after more than a decade . i had a whole load of ge/danfoss vfd's have the caps go bad .

[Larry Caldwell]

I had one starting cap on the compressor fan (not the compressor) go out in 23 years of service. It was a cheap fix. The sequencer that heated up the resistive strips also went bad, but half the heating strips still worked so I never bothered to fix it. I replaced the heat pump last year, and declined the service contract.

[btuhack]

Capacitors are the most likely thing to fail on a properly designed and installed system. That said, there's no need to proactively replace them providing you don't live in death valley. Chinese caps are junk, I've seen them last only a month. Buy/insist on an American capcitor...amrad or titan HD.


Filter changes are the most important any homeowner should be able to manage. DO NOT use a pleated or Hi Efficiency filters if it's 1'' thick. Instead, use a "30 day filter".

[brownbagg]

havent touch mine in 21 years