Hello,
I have a Baxi Barcelona system boiler.
After draining the system down a couple of months ago I am experiencing an annoying problem. The noise of the water being pumped around gets louder and louder, sometimes where pipes are unsecured properly you can hear them vibrating.
I can cure it by isolating the flow and return and draining down the boiler and then topping up. The noise completely goes away, but over time gradually starts to return again.
My guess is that air is trapped at the top of the heat exchanger and by draining down I remove this air somehow! Could this be right?
In the past any air trapped in the system would go to the towel rail in the bathroom (the highest point). But this doesn't happen anymore, it is always OK.
My next idea is to replace the auto vent valve (which is open by the way) and maybe also add some noise reducer.
Any ideas on what is happening here most appreciated,
Thanks,
Graham