Pressure variation/noise from Glowworm swiftflow combi

[NS Dev]

I have a Glowworm swiftflow combi boiler (can't remember the model but it is the smaller one) and had no problems until a few days ago.

I decided to bleed the upstairs radiators as the tops were a bit cool, and in doing so needed to top up the system, which I did. Unfortunately, a few mins later when I turned the cold tap on at the sink I discovered that we had some water main works done and there was air in the cold water feed, which I topped the boiler up with!!!!!

I bled the radiators several times but I now have a pressure swing from 0.8 bar cold to 3 bar hot and some noise from the pipework, difficult to say whether it's air or kettling but the boiler is quiet so I guess its air.

Any ideas? is it still trapped air of have I somehow knackered the pressure accumulator? (the only time I have seen this sort of pressure swing was when there was a knackered accumulator) it was all fine before I bled the radiators and introduced the air from the cold feed!!!!!

Any ideas?

 

[ph]

The expansion vessel could have knackered you need to drain down system and check charge pressure on the top of the vessel it should be between 0.5 and 1bar if not recharge then refill boiler or the diagphram inside could be split hence add a new vessel onto system.One way to check if its the vessel you go to the nearest rad to boiler and turn off both rad valves, then syphon out have of rad from vent cap and close off. you need to open rad valves again leaving temporary expansion vessel if the pressure is ok when hot then its the vessell!!!!

 

[NS Dev]

A bit confused by the latter half of your explanation. Basically you say 1/2 empty the rad nearest the boiler, but then what and what will this show?

 

[ph]

By draining out half of the rad and opening up the rad valves without venting leaving half rad full of air makes a temporary expansion vessel! i wouldnt leave it for long!

 

[wilhelm]

 

[wilhelm]

or just press schrader for a second, and if water p£sses out.....then...
its fkkd.