Service Gas Furnace, AC

[George P.]

Do you LL's ever get HVAC serviced to tune up and prevent problems?
Why or why not? Cost?

Thanks

[Mitch Kronowit]

I've had a couple of annual tune-ups for our primary residence's HVAC because the utility company was offering to cover much of the cost. However, I don't normally call out an HVAC contractor to our rentals unless there's a problem.

There are a couple of things anybody even a little handy can do themselves. First of all is to measure the temperature drop between the return and the outlet of the A/C's evaporator (the coils that actually cool the air). Using a thermometer (IR, digital, or dial), measure the temperature of the air at the return or as close to the blower unit as possible. You want a good solid reading of how cool the air is entering the evaporator coils. Next measure the temperature of the freshly conditioned air as it leaves the evaporator. Some units have a small hole for sticking a probe in, but I usually just pick the register closest to the coil. If the temperature drop is less than 25-30 degrees, there might be a problem and calling a contractor is warranted.

I also check for air flow just using my hand. It's not very scientific, but the air should be blowing out of the register at a healthy pace. If you placed a strip of paper up near it and the flow hardly budges the thing, there could be another problem. In one of our properties, the evaporator coil was very dirty (probably because some idiot was running the A/C without a filter). It wasn't easy to get at, but I cleaned the coils with a citrus cleaner and hosed it off, gently. Voila, the air flow was restored and not a single complaint from the tenants last summer!!!

The last thing you can do is listen and see if the condenser unit (the part outside with the compressor, condenser coils, and fan) is making a lot of racket, such as buzzing, when operating. Ours was doing that a couple of years ago and it was the contactor (the large electrical relay that energizes the unit). When they get old the contact surfaces start to degrade and they begin arcing and buzzing a lot. Replacing one is simple, but you do have to know enough about electrical safety (you're dealing with 220 VAC here) and you have to get the right replacement. I bought one off e-Bay for about $25.

I hope I answered your question. Or did I create more??? ;-)