Harman Accentra 52i-TC: low "rrrrrr" sound like a diesel truck idling in my living room

[megszinNH]

Hey all - Love my Accentra, but over the past few days I have noticed this low rumbling sound when it has been running for a few hours and hot. I have a 4-flue center chimney. The Accentra has its own flue with a liner. The unit was professionally cleaned in August 2025, just 4 months ago. Our buddy ChatGPT says it's likely the combustion blower starting to show its age. The new Accentra was installed in 2018, so 7 years ago. I have put a call into the gent who has serviced us for decades. Should I not run the stove until it is looked at?
Any input appreciated.
Meg

 

[Whitenuckler]

Hey all - Love my Accentra, but over the past few days I have noticed this low rumbling sound when it has been running for a few hours and hot. I have a 4-flue center chimney. The Accentra has its own flue with a liner. The unit was professionally cleaned in August 2025, just 4 months ago. Our buddy ChatGPT says it's likely the combustion blower starting to show its age. The new Accentra was installed in 2018, so 7 years ago. I have put a call into the gent who has serviced us for decades. Should I not run the stove until it is looked at?
Any input appreciated.
Meg

It could indeed be the combustion blower making noise. It might need to be adjusted. It's possible the fan blade got bent or something like that during the cleaning. It could also be a bearing that is going bad. I would run it if you have to, but otherwise wait.