Knocking in NG hot water system

Margaret Ross

Thanks for the response. That sounds like I should just let it do its thing and not worry...is that right? Thanks again!

Margaret Ross

knocking in NG hot water system

I wrote a while back about an some noise coming from my pipes after a recent installation of a new prestige solo 110 boiler in my home. The noise that used to sound like rain going down a gutter, or a tea kettle just before it comes to a full boil, has progress to knocking in all of the boilers. It's not the kind of rythmic knocking I hear in steam radiators when they're heating up. It's a periodic, one knock and it's done kind of thing.

I thought the original noise was caused by air in the pipes, and you recommended venting. All of the radiators have small vents for bleeding water. We bleed them every year until water flows. Maybe we're not bleeding them enough? All of the vents were used and (to the best of my knowledge) sealed tightly when the team finished the install and filled the pipes.

What I'm not clear on is how air is getting into the system. Is it possible that one of the vents is broken and is letting air in? If the vent was open at all and the boiler was on, and the radiator was working (hot), wouldn't it be spitting, not sucking?

Thank you for your time!!!

kpc_52

sounds like...

expantion noise to me as the boiler and piping heats up.

kpc_52

hard to say....

from sitting here...but probably.