Help !
The Boiler was accidentally overfilled to 3 Bar.
The inlet valve is shut off but every time I bleed a radiator the pressure drops to around 2.5bar but then instantly rises again to 3bar as soon as I stop bleeding it. It's as if it's directly connected to the mains. There is slight drip from the overflow but not much.

How do I drop the pressure back to 1bar ?

Thanks in advance for any help.

Colin P:, March 2011

If the filling key is removed, the only place that mains water can mix with CH water is the domestic heat exchanger, quite common on the CDI

Change the DHE, also the prv may need changing too.

Carefree, March 2011