Furnace Symptom Checker: What's Wrong With Your Heat?
Two quick questions, plain-language answers. Pick the symptom that sounds like yours and we will point you toward the likely cause and the right next step.
How the Checker Works
When we get a call about a furnace acting up, the first thing we ask is what it is doing, then one follow-up question. That is all this tool does. Pick your symptom, answer the follow-up, and you will get the most common causes we see on Clarksville service calls, plus the page that explains the fix in detail.
One honest limit: this is a narrowing tool, not a diagnosis. Two furnaces can share a symptom and need different repairs. Use the result to have a smarter conversation with the tech, not to order parts.
When to Skip the Checker and Call Now
Some situations do not need a quiz. Call (931) 800-6452 right away, day or night, if any of these fit:
- You smell gas (rotten-egg odor). Leave first, call your gas utility or 911 from outside, then call us once the area is cleared.
- A carbon monoxide alarm is sounding. Get everyone out, call 911, do not go back in to "check the furnace."
- No heat during a hard freeze with elderly family, infants, or medical equipment in the house. We prioritize those calls.
- An electrical burning smell or visible sparking at the furnace. Shut it off at the thermostat and call.
For everything else, the checker above or our furnace problems guide will get you oriented. And if you would rather just talk it through, that is what the phone is for: (931) 800-6452.
Worth bookmarking: the U.S. Department of Energy's guide to residential furnaces and the EPA's indoor air quality resources, including combustion safety basics.
Checker Questions
Symptom Checker FAQs
Can this checker actually diagnose my furnace?
No, and it is not trying to. The checker narrows your symptom to the most common causes we see on Clarksville service calls, so you land on the right page and know what to tell the tech. Only an in-person visit with testing confirms the fault.
I smell gas near my furnace. What should I do right now?
Leave the house immediately. Do not flip light switches, light anything, or use your phone inside. Call your gas utility or 911 from outside. Once you are safe and the area is cleared, call us at (931) 800-6452 and we will check the furnace.
My furnace makes a loud bang when it starts. Should I keep running it?
Turn it off and do not keep restarting it. A startup bang often means delayed ignition, where gas builds up before the burners light. That is hard on the furnace and not something to ignore. Call and describe the bang; we treat it as priority.
The checker suggests a flame sensor issue. Can I clean it myself?
Sometimes. It means opening the furnace cabinet and handling a small, fragile rod with the power off. A gentle cleaning fixes some no-heat calls. If anything looks unfamiliar, or the furnace still will not stay lit, stop and call. Gas components are not a learning project.
Clarksville HVAC Repair Pro
Still Not Sure What's Wrong? Talk to a Tech.
Describe the symptom in your own words. We will ask the right follow-ups and get someone out to look at it.