Worcester 28 Si Mk2 Combi Boiler

[gino]

Help please.

Pressure gauge settles at 3.5 bar when system has been run and switched off. Everything seems fine when boiler is running. Have fitted new filling loop. Still same problem. Any suggestions guys?

Thanks

[Christian McArdle]

If you are not constantly adding water:

1. Knackered gauge.
2. Filling loop not disconnected. (You should remove the hose after use).
3. Leak in internal heat exchanger that lets mains water into the system.

If you are constantly adding water:

1. Failed/inadequete expansion vessel.

I suspect (3), which is unfortunately a very expensive repair/new boiler situation.

Christian.

[Philip Jackson]

Gino, are you saying the pressure is 3.5 bar hot? If I assume that the pressure drops to