Why Is My Furnace Not Turning On After Sitting All Summer?

Your furnace has been off for months, and now the first cool Las Vegas night is here. You turn up the thermostat and nothing happens. Before assuming the furnace has failed, check a few things you can safely reach.

Start With These Safe Furnace Checks

Check the Thermostat

Make sure the thermostat is set to HEAT and the temperature is set above the current room temperature.

If the screen is blank and your thermostat uses batteries, replace them. Leave the wiring behind the thermostat alone.

Check for an Obvious Power Issue

Check the normal furnace switch and circuit breaker. If the breaker has tripped, do not open the furnace or test electrical parts inside the equipment.

Check the Air Filter

Look at the filter if it is easy to reach. A filter packed with dirt restricts airflow and can keep the furnace from running normally. Replace it with the correct size if it is dirty.

If the furnace still will not start after you replace the filter, schedule service so we can find what is keeping it from turning on.

Why a Furnace Won't Start After Months of Inactivity

Ignition or Startup Component Problem

Several parts have to work before the furnace produces heat. A problem with the ignition system, controls, or sensors can stop the furnace before the burners come on.

These parts need to be checked by a technician.

Safety Switch or Control Issue

Safety controls shut the furnace down when they detect a problem. If the system keeps shutting off, do not bypass a safety switch or keep trying to restart it.

Airflow or Overheating Problem

Restricted airflow can make the furnace overheat and shut down. If the filter is clean, the blower or another part inside the system needs to be checked.

Equipment or Electrical Failure

A failed motor, control board, or electrical part can keep the furnace from starting. Leave electrical testing and internal furnace repairs to a technician.

What If the Furnace Turns On but Blows Cold Air?

A furnace that runs but keeps blowing cold air has a different problem from one that never starts.

The blower can move cool air briefly at startup. If the air stays cold and the house is not warming up, something is stopping the heating cycle.

Furnace repair finds the failed part or control problem that is keeping the furnace from producing heat.

What If the Furnace Starts and Stops Repeatedly?

A furnace that starts, runs briefly, shuts off, and starts again is short cycling.

Restricted airflow, controls, or equipment trouble can interrupt the heating cycle. If a dirty filter is not the problem, have the furnace checked.

Furnace Startup Problems That Require Immediate Attention

Stop troubleshooting if you smell gas, see smoke or sparks, hear a carbon monoxide alarm, or notice a strong electrical or burning odor.

For a suspected gas leak, leave the area and follow your gas utility or emergency-service instructions. Do not operate switches or keep trying to start the furnace.

Leave the area if a carbon monoxide alarm sounds and follow emergency guidance.

Why First-Startup Problems Show Up in Las Vegas

Las Vegas homeowners can go for months without using the furnace. When cooler nights return, that first heating cycle is your first chance to find a startup problem.

Test the heat before the first cold night you need it. New noises, trouble starting, or other fall HVAC warning signs give you time to schedule service before temperatures drop further.

If your home uses a heat pump instead of a furnace, our heat pump services cover the heating and cooling equipment used by that system.

When to Call for Furnace Repair

If the furnace still will not start after the thermostat, power, and filter checks, it is time to have the equipment diagnosed. Continued cold air, short cycling, or repeated shutdowns also need service.

Anytime provides heating services for furnaces, heat pumps, and other heating equipment throughout the Las Vegas area.

Schedule Furnace Service Before the Next Cold Night

If your furnace is not starting or heating the house, schedule heating service before the next cold night.