Summertime in the Chicagoland area is almost here and when air conditioning becomes really important, especially if you are working remotely at home. The first time you turn on your unit is always nerve-wracking given that it’s likely been close to a year since you last used it. If after troubleshooting with these 3 tips and you can’t solve the problem, contact Hobson Plumbing and Heating for assistance. Once you’ve figured out why your AC unit won’t turn on, fixing it can often be surprisingly easy. 

Trip the circuit breaker

Your central electrical panel splits electricity from your main line out to every electrical fixture in your home. This often will include your thermostat (if it’s connected instead of battery-operated) and your AC unit. Circuit breakers trip to protect your fixtures when there’s a surge of electricity. Tripped circuit breakers turn all the electricity off to the fixture they’re protecting until it’s been reset.

Tripped circuit breakers are pretty common. You may only notice that a circuit breaker tripped when you notice the fixture won’t turn on. Locate your main electrical service panel and look for tripped breakers. The tripped breaker will be shifted down to the “OFF” position rather than the “ON” position, and may also be indicated by a red warning label. Simply flip the circuit breaker back on and check to see if your AC unit kicks back on.

Test the thermostat

If your thermostat isn’t working properly, then it may not send the correct cooling instructions to your AC unit. Even if the AC unit is working fine, it will never turn on because it doesn’t know that it’s being told to do so. Thermostats are usually easy to spot when they malfunction. If the display won’t turn on, it doesn’t respond to what you’re suggesting it does, or immediately loses programming, these all point to signs that something’s wrong. Try also checking the batteries to see if they need to be replaced or, again, tripping a circuit breaker.

If nothing seems wrong with your thermostat, there is one relatively simple way to test it if you’re comfortable taking this next step. First, turn off the power to your thermostat (IMPORTANT FOR YOUR SAFETY). Take down your thermostat and open up the access point in the back with a screwdriver. Find the red and green wires, unscrew them, and manually wrap them together. Then, let go of the wiring and flip the breaker back on. If the AC unit starts, then you need to replace the thermostat.

Clear the Drain Line

While you have the access panel open to your AC unit, find the condensation pump. This pump removes moisture that tends to build up on the unit’s condensation tray by pumping it through the drain line. This drain line deposits the condensation outside of the unit as intended. If the drain line becomes clogged though then the pump won’t be able to remove condensation. Instead, it will build up inside the AC unit until the unit’s safety features stop working properly.

Unclogging the drain pump or cleaning your AC Unit’s condensate line is fairly easy. First, always remember to turn off the power that leads to the AC unit. Locate the tray, pump, and drain line. If you have a hand vac, suction out any excess moisture in the tray. Then, disconnect the drain line and use the hand vac to suction and remove any clogs inside that may exist. If you don’t have a hand vac, use water or an air compressor. After reassembling the components, add a little moisture back to the tray to make sure everything is working properly.

If you’ve tried each of these common troubleshooting tips and you still can’t get your AC unit to turn on, please don’t panic! These steps haven’t exhausted all the possible issues, just the ones you should try yourself. You can always call Hobson Plumbing and Heating at 630.761.3400 and we will be happy to assist.