Why is my furnace not turning on?
It is usually one of six things: thermostat settings, power, a clogged filter, ignition, a safety switch, or the control board. Some are safe to check yourself in five minutes. The rest need a licensed technician. Here is how to tell the difference.
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Six reasons a furnace will not start
- Thermostat issuesSet wrong, dead batteries, or not communicating with the furnace.
- Tripped breaker or power lossNo power, no start. Check the panel, but do not reset a breaker over and over.
- Dirty or clogged filterRestricted airflow trips safety shutoffs that keep the furnace off.
- Ignition problemsModern furnaces use an electronic igniter. A failed igniter means no flame.
- Safety or limit switchOverheating or poor airflow makes a safety switch shut the system down.
- Faulty control boardInternal control failures can stop the startup sequence cold.
Five checks before you call
Do not bypass safety switches, open the burner area, or work on the gas valve. If you smell gas, leave and call the gas company first.
- Thermostat on HeatSet to Heat and a few degrees above the room temperature.
- Fresh batteriesReplace the thermostat batteries if it has them.
- Breaker panelLook for a tripped breaker. If it trips again, stop and call.
- Air filterReplace a dirty filter. It is the cheapest fix there is.
- Furnace switch onThe light-style switch near the furnace is often bumped off.
What a furnace no-start repair costs
On top of the $210 service call. Typical ranges, parts and labor, priced in writing before I start.
| Item | Typical price |
|---|---|
| Flame sensorLights, then shuts right off. | $125 to $225 |
| IgniterClicking but no flame. | $150 to $275 |
| Pressure switchInducer runs, burner never lights. | $175 to $325 |
| Control boardNo startup sequence at all. | $400 to $900 |
| Inducer motorNoisy, or not running. | $450 to $850 |
Repeated failures on an old furnace?
If your furnace is over 12 to 15 years old and failing again and again, it may be time to look at replacement. I will run the numbers with you.
Maintenance
Furnaces not serviced before peak season fail more in extreme cold.
Plans from $199 a yearHVAC maintenanceReplace
I look at the house and ductwork before anybody talks price.
Estimate freeReplacement optionsWhat customers say
“The technician was knowledgeable, friendly and professional. Hartzell’s Heat & Air has had our business for 10+ years and we’ve received great service consistently.”
Katie B. · Google review · May 2025
“Tim and Juan done an excellent job servicing my heatpump. We were really impressed of how thorough they checked everything.”
Steve I. · Google review · March 2026
Straight answers
Why is my furnace not turning on when the thermostat is working?
The problem is likely inside the furnace: ignition, a safety switch, or an electrical fault. Past the five safe checks, it needs a technician.
Should I reset my furnace?
If your system has a reset, use it once and cautiously. Repeated resets without fixing the cause can do more damage.
Is it safe to troubleshoot a furnace myself?
Thermostat, filter and breaker checks are safe. Do not bypass safety switches or work on the gas valve or heat exchanger. If you smell gas, leave and call your gas company first.
How much does it cost to fix a furnace that will not turn on?
The service call is $210: $99 dispatch plus $111 diagnostic, not credited toward the repair. Common no-start repairs run $125 to $900 depending on the part, priced in writing first.
How quickly can you respond to a no-heat call?
No-heat calls are prioritized, especially in winter. Same-day service where the schedule allows across Kingfisher, Canadian, Oklahoma, Garfield, Major, Logan and Blaine counties.
Tell me what it is doing
Clicking with no flame, starts then quits, blower with no heat. Describe it and I will tell you straight what I think it is before I drive out.
Call 405-375-4822Kingfisher, Oklahoma City, Enid, Guthrie, Yukon, El Reno and every town between. Counties: Kingfisher, Canadian, Oklahoma, Garfield, Major, Logan, Blaine.
