Kettling and Circulator Pump

DIYer123

Trying to troubleshoot knocking sound, likely kettling, in Utica boiler. Service Tech recommended replacing circulator pump after checking chamber, changing nozzle size and bleeding system of air.Could an old baseboard circulator pump cause kettling in a boiler ? Thanks

hot_rod

kettling or percolating sounds often indicate the boiler is scaled inside.

If so a cleaner needs to be run for a day or so to loosen and flush.

But a sound is in the ear of the beholder. It could bean air noise, pump noise, combustion noise, etc.

The cleaner wouldn’t hurt regardless.

Is there any leaks that may be causing fresh water to enter? That scales a boiler quickly.

Jamie Hall

Sound is tricky — but if this sounds as though it is coming from the boiler and not the pump, it's not the pump. I'll go with @hot_rod .