Boiler Knocking Sound

DIYer123

Hello,

Homeowner here with a 27 year old Utica oil boiler. Noticed a knocking sound coming from the boiler for about 30 or 45 seconds after boiler stops running. When it starts running, I hear a similar knocking sound coming through the baseboard about a short time later (evidently from the boiler) although I don't hear it come from the boiler because the boiler is too loud. Any idea what is causing the noise?

Thank you

Jamie Hall

Expansion noise?

EdTheHeaterMan

Temperature. There is a gauge on the boiler that has 2 pointers. One of them is for temperature, the other one is for pressure. What are the needles point at when you hear the noise?

You may have had something that changed recently as a result of wear and tare. But to find out what it is, we need a starting point. The information on that gauge is the starting point.

Sometimes the pressure needle will bounce a little when you hear the knocking. That information would be helpful