Why is my gas furnace getting so hot?
Excessively high temperatures that cause a furnace to heat for only ten minutes before blowing normal air can stem from a worn gas manifold pushing out too much gas pressure, or inducer and condensate issues triggering an E09 error. Homeowners are forced to troubleshoot the system themselves to keep their pipes from freezing when HVAC technicians are booked out for a week or unable to resolve the issue.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
Found another way around this?
Share your steps and trade-offs so fellow engineers don't have to reinvent the wheel. No account required.
- 1turning blower speed all the way upDid this help you?
- 2planning to return with a manometerDid this help you?
- 3watching YouTube tutorials and reading Reddit posts for guidanceDid this help you?
- 4attempting DIY repairs like cleaning flame sensors and clearing condensate linesDid this help you?
- 5using a volt meter to check wiring connectionsDid this help you?
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“My gas furnace was just blowing normal air, E09 error which is condensate issues or inducer issue.”source ↗
“it is busy season for hvac apparently because it will be a week before they can send anyone out so i got to meddling with it myself so my pipes don't freeze”source ↗
“had a tech come out last may because it was doing heat for 10 min then normal for 20-30 min then heat 10 min and repeat. he messed with it for 3 hours then left without resolving anything.”source ↗
“I believe I’m honestly stumped here on why this thing is getting as hot as it is do you think I should check the gas pressures maybe the gas manifold has worn down and is pushing to much out.”source ↗
Where this came up
People with this problem also raised
- 5New HVAC unit won't heat and makes clicking sounds
- 2Air locks trapping in tight hydronic heating spaces
- 7Mini-split can't keep house warm when it freezes outside
- 6Why is just one upstairs room so hot in the summer?
- 3Why is water pooling inside my furnace?
- 4HVAC contractor installed mismatched heating and cooling parts