Why is my boiler making a constant humming noise when heat is on?
A constant humming or whirring sound that starts when a specific heating zone turns on and stops the moment it turns off is typically tied to active heating components in that circuit. This persistent background noise can drive homeowners mad, especially in a quiet house, leading to concern that an older or newly installed unit is developing a fault.
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.
- 1Opening and observing the boiler while running to inspect for issuesDid this help you?
- 2Changing boiler or inducer motor speed settings to alter the frequency/noise levelDid this help you?
- 3scheduling a technician to come out and diagnose the issueDid 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.
“when its quiet in the house we can hear this slight humming/similar to the sound the alta makes when its running. almost sounds like a small car/whirr. its constant when the downstairs heat zone is on. the second the zone is off the sound disappears.”source ↗
“I’m sure it’s not. Just driving me mad”source ↗
Where this came up
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