Hi guys,
Having a weird problem with what I believe is an airlock in my CH system. It's a pumped system, and the rads aren't collecting much air (been bled daily for about 3 weeks now) and appears to be working ok, but the flow and return pipes to the boiler appear to be making a noise like trickling water.
With the boiler output control cranked up, it occasionally blows out the cut-out switch, so I've backed it down to half way successfully, but the trickling noise remains.
When the boiler stops (and the pump cuts out too), I can hear water almost sloshing back to the boiler making me think I have an airlock. It occasionally 'phuts' and pops when it's been running for a while (again, making me think there's air in the heat exchanger).
I've got a drain off c*ck on one of the pipes to the boiler, and when I drained and refilled the system, it did let out quite a lot of air before running water came out at a constant rate, but there's no drain off on the other pipe (the flow I think). Perhaps trapped air in that part of the system?
The only bleed valves not on the rads are on the pump (no air coming out) and a capillary valve on a high point on the system (again, with negligable air coming out).
Any suggestions?
Cheers,
Paul