Fixing four common air conditioner problems

When the weather heats up, you want to put your air conditioner on, so make sure it is well maintained, so you don’t wind up stewing in frustration.But in order for it to do its job on sweltering days, you have to stay atop repairs, whether you do them yourself or hire an appliance repair and service professional to take care of them for you.

There are a variety of reasons your AC won’t kick in, including a tripped breaker switch, blown fuse, and clogged vents. But the most common cause is a broken thermostat.

Also, you should make sure the furnace power switch is turned on and that the outdoor condenser’s power switch hasn’t been turned off. Check, as well, that the 240-volt disconnect next to the compressor hasn’t been shut off.

While an air conditioner by its nature makes noises, some sounds should give you pause for concern. If it vibrates or rattles, for example, the unit may be installed incorrectly.

Some older units are driven by belts rather than motors. A squealing noise can occur when the belt connected to the blower has slipped. If a direct-drive blower is squealing or making a grinding noise, shut off the unit—the motor’s bearings are likely shot.

In all these cases, you should call a service professional to address the problem.

Make sure the thermostat has power to it; most digital thermostats will be completely blank if there’s no power. If the thermostat is blank go to the furnace or fan coil and unplug it for a few minutes, and then plug it back in to see if this resets the system.

Air conditioners create a lot of condensation, which exits through a drain tube to a floor drain or to a small electric “condensate pump” that moves it outdoors or to a drain. Water leaking or pooling at the base of the appliance is a sign that a drain tube is leaking, something is blocking the water’s flow, or the condensate pump is not working.

To address the problem, make sure:

• No drain tubes are leaking and need replacement.
• The condensate pump is plugged in and working.
• The pump isn’t stuck or broken. Test the pump by pouring water into its collector. The pump, which is turned on by a ball float inside that rises with the water level, should start. If not, it should be cleaned or replaced.
• If the pump runs but doesn’t empty the pan, that the ball-like check valve just before the discharge tube isn’t stuck.
• Ice isn’t blocking the tube. If it is, you either need to clean or change your filters, or top up your refrigerant supply.

If you properly maintain and repair your air conditioning system, you’ll get sweet relief when you switch it on, instead of stewing in the heat.