How to Repair Window Air Conditioner?
You’ve pulled the old window air conditioner unit out of basement storage and installed it in your window, only to realize — just as the first really hot days of summer hit — that the unit’s basically just blowing hot air.
Well, you’ve had the thing for a lot of years, and perhaps it’s seen better days. Time to go air-conditioner shopping, right? Well … maybe.
Start with the basics. And as usual, the basics mean cleaning.
Here at PDIY, we go on and on about how a clean appliance is a happy appliance. But dirt is the special enemy of window air conditioners, and if you’re anything like us, you may not fully appreciate just how filthy these things can become.
You can do a lot. But there are limits.
As is so often the case, we’ve found there are three basic levels to window air conditioner maintenance:
- The basic stuff that every air conditioner owner needs to do;
- More advanced and aggressive steps you can take if your fingers are feeling nimble and you want to really take charge of this appliance;
- Stuff we wouldn’t even know how to try. This is when it’s usually time to bring in the professionals.
The basic stuff: Filters
The first place you’ll find huge amounts of collected dust and dirt is in the unit’s filter. On most models, you just pop open the front grille and it’s right there; it’s supposed to be easily accessible. Pull it out and rinse it.
We know this may sound obvious. But it’s such an easy task, we hadn’t bothered to do it the last three summers.
The basic stuff: Coils
In the front of the unit, you’ll find the evaporator coil; in the back, the condenser coil. And if you’re anything like us, you’ll find these things look like they’ve been through a war.
These delicate vanes of light-gauge aluminum can only do their jobs if they’re clean and separated. A vacuum cleaner will do a dandy job on the dust and dirt.
To straighten and separate the vanes, you need what’s called a fin comb: an inexpensive little tool that pushes the bent vanes back into place.
More ambitious: The insides
If the unit is clean and seems to be in good repair and still isn’t cooling properly, it may be time to cross that boundary between simple cleaning and more ambitious maintenance by removing the outer housing.
Even this isn’t always easy, especially on an old unit: We stripped at least one screw trying to do it.
Once the air conditioner’s opened up, you’ll see plenty of dirt and dust, especially around the fan and fan motor. Vacuuming this out can’t hurt. While you’re in there, take the opportunity to clean out the drain ports.
If you happen to have a multimeter (otherwise known as a volt-ohm meter) handy — and we don’t — you can use this to check your air conditioner’s thermostat and fan motor. If these things aren’t drawing power properly, that can be your problem. The trouble is, at this point you’re starting to drift into what we would call in-over-our-heads territory.We trust you to be sure your air conditioner is unplugged before you go to work. But window units also have either one or two capacitors that store power even when the unit is unplugged. You must discharge these — the owner’s manual will tell you how — to avoid risking a nasty, even fatal, electric shock.
OK, I’m in over my head.
With some window units, especially newer ones, it’s almost impossible to even remove the housing. Once you do, you’re looking at a whole bunch of electrical and electronic components that really need a professional to diagnose and repair properly.
The trouble is, with window air conditioners selling for as little as a couple hundred bucks, it won’t take too much of a repairman’s time for you to be paying more to try to fix an old unit than it would cost to get yourself a new one. So on the one hand, it’s certainly worth a try to fix it yourself if you can. On the other hand, when it comes time to call a repairman, it’s important to find one you can trust and then discuss with him whether repairing the unit is worth the attempt.