Before the first cold night, take a look at the controls and accessible parts of your heating system. A short check can help you describe a problem before you need the heat every day.

Keep the equipment manual handy. Do not open cabinets, touch wiring or work inside the outdoor unit. Turning the thermostat off does not disconnect electrical power.

Check controls and airflow

  1. Read the thermostat. Review its Heat setting and schedule. Check the manual for any battery or warning message.
  2. Review the filter instructions. Check the replacement schedule and access guidance. Leave filters behind equipment panels to a technician.
  3. Look at the vents. Note furniture or rugs blocking supply vents and return grilles. Report rooms with unusually weak airflow.
  4. Observe the outdoor unit. If you have a heat pump, look from a safe distance for visible damage, ice or blocked airflow. Do not reach through the grille or touch a fan that appears stopped.
  5. Check your alarms. Test smoke and carbon monoxide alarms according to their instructions. Replace batteries or the alarm as directed by the manufacturer.

Observe one normal heating run

If there are no signs of damage, gas odor or electrical trouble, use the thermostat according to the equipment instructions. Check whether the system responds and the room begins moving toward the set temperature. Do not repeatedly start and stop the system to test it.

A heat pump’s air may feel less hot than a furnace’s. On a cold, damp day, defrost can briefly interrupt heating. You may see steam outside or hear a whoosh.

A faint dusty smell can occur at the first heating run after a long break. It should fade. Do not dismiss a strong, persistent or returning smell as dust.

Stop using it and arrange service

When there is no smoke, gas odor or immediate danger, stop using the system and call for heating repair if:

  • It smells of burning plastic or wiring.
  • A breaker trips when the heat comes on, or trips again after you reset it once.
  • It makes grinding, banging or loud buzzing sounds.
  • It runs without warming the house.
  • The outdoor unit stays covered in heavy ice rather than clearing during defrost.

Do not open equipment panels to investigate or keep restarting a system that shuts down.

Know when to get out

If you see smoke or fire, get everyone out, stay out and call 911 from a safe place. Do not delay leaving to adjust the thermostat.

If you smell gas, leave without using switches or a phone indoors. From a safe place outside, call 911 and your gas utility. Do not return until emergency responders say it is safe.

If a carbon monoxide alarm sounds or you suspect CO poisoning, get everyone outside to fresh air and call 911. Do not go back inside until emergency responders say it is safe.

Leave internal checks to a technician

These observations do not replace a heating inspection. A technician can assess electrical parts, heat-pump operation and, for fuel-burning equipment, the heating and venting components. Ask what a maintenance visit includes for your equipment.