Heater Not Working? Check These 4 Things Before You Call (San Antonio)

San Antonio winters are short, but the cold fronts that blow through are no joke — and furnaces here tend to fail on the first cold night of the season, after sitting unused since February. Before you call anyone, run through these four checks. They solve a surprising number of no-heat calls, and they cost nothing.

1. Check the thermostat

It sounds obvious, but it is the most common culprit. Make sure it is set to heat, not cool or off, and set the temperature a few degrees above the current room temperature. If the screen is blank, replace the batteries. If it is still blank after fresh batteries, the thermostat itself may have failed — that is a quick, inexpensive fix.

2. Check the air filter

A clogged filter chokes airflow and can make the furnace overheat and shut itself down on purpose. If you cannot remember the last time you changed it, pull it out and hold it up to the light. If light does not pass through, replace it and give the system ten minutes. This one fix brings a lot of "dead" furnaces back to life.

3. Check the breaker and the switch

Furnaces have a dedicated breaker in your electrical panel, and most have a power switch on or near the unit that looks like a regular light switch. Both get flipped accidentally — by kids, by storage boxes in the attic, by someone doing other work in the house. Reset the breaker once and flip the switch on. If the breaker trips again, stop there and call — that points to an electrical problem inside the unit.

4. Check the gas

If you have a gas furnace, confirm the gas valve on the line leading to the furnace is open (the handle runs parallel to the pipe when open). If you smell gas at any point, leave the house and call your gas company first, then us.

Still no heat?

If you have been through all four and the house is still cold, the problem is inside the furnace — usually an ignitor, a flame sensor, or a control board. Those are the three most common failures we see, and they typically run $149 to $385 installed. You can see what every common repair costs on our furnace repair page before you ever pick up the phone.

The fastest way to get heat back

Text us and tell us what the furnace is doing — clicking but not lighting, running for a few seconds then quitting, or completely dead. Clint will give you his best read on what is wrong and what it should cost, right over text. During cold snaps we prioritize no-heat calls and can usually get to you the same day.

And once you are warm again, ask about the Comfort Club — $250 a year, includes a 21-point inspection, and it is how our customers avoid meeting us on the coldest night of the year.