Furnace Not Heating During a Cold Snap? Check These First

Serving homeowners in Memorial and nearby Houston neighborhoods.

A furnace that stops producing heat is stressful during a sudden cold snap. Houston furnaces run far less often than air conditioners, so a system that has sat idle for months can surprise a household on the first cold morning. Many no-heat calls turn out to have simple causes, so a few careful checks before you call can help you understand what is happening. Some problems, however, need a licensed technician right away.

Check the Thermostat and Power First

Start with the thermostat. Make sure it is set to heat rather than cool, the setpoint is above the current room temperature, and the batteries are fresh if it uses them. Then check the furnace power switch, which is often a light-switch style control near the unit, and look at the breaker panel for a tripped breaker that serves the furnace.

Look at the Filter, Vents, and Airflow

A badly clogged filter can cause the furnace to overheat and shut down on its safety limit. Pull the filter and hold it up to a light, and replace it if you cannot see through it. Walk through the house and confirm that supply registers are open and not blocked by furniture or rugs, and that return grilles are clear.

Know the Warning Signs

If you smell gas, hear a hissing sound near the unit, or notice an unusual burner flame, leave the house and call your gas provider or emergency services from outside. If the furnace makes loud banging noises, produces burning smells, or your carbon monoxide detector alarms, shut the system off and get help immediately.

When to Call a Technician

If the thermostat and breaker check out, the filter is clean, and the furnace still will not fire, the cause may involve an ignition component, a flame sensor, a control board, or a safety switch. These repairs require proper tools and training. Ask the technician to explain what failed, whether any part is covered by a warranty, and what your options are before approving work.

If your heat is out and you want a qualified technician to take a look, reach out for a free estimate and we will walk through your options.

Frequently Asked Questions

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