Heating problems · Residential
Heating not working: thermostat and airflow checks, with clear safety limits
Identify a no-heat symptom without opening burners, relighting equipment, or bypassing a safety control.
Last reviewed
Deal with danger before checking settings
If you smell gas or suspect a gas leak, leave immediately. Do not operate switches, use a phone inside, light a flame, or try to locate or stop the leak. From a safe location away from the smell, contact the gas utility or emergency services. Do not return until responders say it is safe.
If a carbon monoxide alarm sounds or CO exposure is suspected, get everyone outside to fresh air and call emergency services from outside. CO has no smell, so the absence of an odor is not reassurance. Do not remain indoors to investigate the furnace. Smoke, arcing, or an electrical burning smell also ends troubleshooting; stay away from the equipment and seek emergency help for immediate danger.
Supporting references: Furnace Troubleshooting, Heat Pump Not Heating, Carbon Monoxide Fact Sheet | CPSC.gov, Piedmont Natural Gas monitoring areas impacted by Tropical Storm Debby, advises customers on flood-related equipment damage.
Identify what kind of heating is installed
A furnace and a heat pump do not behave the same way. A heat pump may supply air that feels less hot than furnace air while still heating the house. Its outdoor unit normally operates in heating mode, and defrost can temporarily change its sound and air temperature. Check the thermostat or owner paperwork rather than removing equipment panels to identify the system.
Write down whether nothing starts, the fan runs without warmth, or the system runs but the room temperature keeps falling. Note whether the issue affects the whole house or only one area. This helps separate a control complaint from an airflow or capacity complaint without diagnosing a component remotely.
Supporting references: Furnace Troubleshooting, Heat Pump Not Heating, Carbon Monoxide Fact Sheet | CPSC.gov, Piedmont Natural Gas monitoring areas impacted by Tropical Storm Debby, advises customers on flood-related equipment damage.
Use only ordinary owner controls
Confirm Heat mode, a setting above the displayed room temperature, and any schedule or hold that may override your choice. If the display uses replaceable batteries, follow its manual. Allow any normal delay described there rather than rapidly switching modes. Do not disconnect thermostat wires or use an installer menu to change system configuration.
With the equipment off, check an owner-accessible filter and replace it only with the specified type when needed. Keep return grilles and supply registers unobstructed. Do not remove burner doors, attempt to relight a pilot, adjust gas valves, or defeat a door switch. If a breaker has tripped or the equipment repeatedly locks out, stop restarting it and report the pattern.
Supporting references: Furnace Troubleshooting, Heat Pump Not Heating, Carbon Monoxide Fact Sheet | CPSC.gov, Piedmont Natural Gas monitoring areas impacted by Tropical Storm Debby, advises customers on flood-related equipment damage.
Plan for a safe wait and a useful service visit
Arrange service if ordinary settings and a clear filter do not restore normal operation, or if the equipment starts and stops without warming the house. Provide the model information, displayed message, room temperature trend, and when heating last worked. Mention any outage or recent work.
Move occupants to a warm, safe place if indoor conditions are becoming unsafe. Never use an oven, outdoor grill, or generator indoors for heat. Ask the service provider to explain the finding, any limitations on operating the equipment, and what must be verified before normal use resumes.
Supporting references: Furnace Troubleshooting, Heat Pump Not Heating, Carbon Monoxide Fact Sheet | CPSC.gov, Piedmont Natural Gas monitoring areas impacted by Tropical Storm Debby, advises customers on flood-related equipment damage.
Sources
Get the right repair started.
Call with your location, equipment type and symptoms. Confirm coverage and appointment availability directly.