So this central heating thing, lots of noise. New system, it is. Gravity HW and pumped CH, with an immersion tank heated either by the immersion heater (obviously) or the indirect coil passing through the tank.
This noise sounds like rushing water, and I can bleed all the air from the rads, and then have more in there 30 mins later. So I'm assuming that it's drawing air in from somewhere. The only open part of the system is the feeder tank, but that's full of water, and the air separator pipe, which overhangs the feed tank, but is not submerged.
I plan to extend the air separator pipe a little, so that the end is submerged, so that if it is sucking air back that way (which I imagine it shouldn't) then there'll be no air to suck back, but air can still get out.
Any other suggestions? Any ideas on how to find where the air is getting in, if it isn't through the air separator pipe?
Matt