Propane boiler making puffing exhaust noise in extreme cold
When temperatures drop significantly and multiple zones call for heat, propane boilers can develop a rhythmic puffing exhaust noise that may escalate into a loud whistle. This issue can persist even after replacing the fan and cleaning the unit, forcing homeowners to shut the system down manually.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1Replacing the fan and cleaning the unit
- 2Shutting off the boiler
- 3Replacing the circulator
- 4Calling a qualified repair person
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“Boiler (Lochinvar) making puffing noise from exhaust. Only happens when its super cold and both zones (2 zone system) are calling for heat. Fan has been replaced and unit cleaned, yet issue remains.”source ↗
“Made this noise for about 20 minutes at which point became a loud whistle and I shut it off.”source ↗
Where this came up
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