The worst time of year to start having HVAC problems are the middle of summer (and the dead of winter). Not only are you quickly experiencing the discomfort of no heat or air, you also have that sinking sensation in your gut that something is wrong and it’ll probably cost money. Here’s what to check first, before you even have to call the technician (or maybe while you’re waiting for them to pick-up). 


Believe it or not, sometimes we all miss the simplest reasons our HVAC is acting up—the power is off. If the power is off in your house, or in your neighborhood, there is probably nothing wrong except that you’ll have to wait for the power to come back on. 

Air Filter

Airflow to your unit is important and if you haven’t been changing your air filters regularly, the restriction can cause your unit to slow down or drag, especially when it’s trying to work hard during the summer heat. For twenty bucks and five minutes of work, you’re HVAC can be frigid once again. 


If the thermostat display doesn’t work, try changing the batteries. 

Circuit Breaker

Check the circuit breaker in the breaker box. If it’s been tripped (the one switch that doesn’t look like the others), reset the breaker. Breakers can trip for a variety of reasons, and if it happens once it’s no big deal. But if the breaker keeps tripping, it’s best to get an electrician to come look at the problem.  

On-Off Switch

On many units there’s an on-off switch next to the indoor air handler unit. For whatever reason (pets, kids, random incidents) this switch can get flipped. Best to double check. 

Outdoor Switch

There’s another switch on the outside unit and it can get flipped for all the same reasons. Make sure it is plugged in or flipped on. Be very careful, as this switch controls the 240 volts of electricity to the outdoor A/C unit and it’s very dangerous.

Condensation pump 

There’s a water safety switch under the pan under the unit to stop water from leaking into your home. If there’s no water in the pan, or it looks old, try emptying the pan, flush the drain line and see if it makes the unit start working again. 

If you’ve checked everything and there’s still a problem, definitely contact your HVAC service technician and have them come out. You don’t need to be suffering in this heat.