Boiler Pressure Problem

[Stephen]

Hi There

I'm having problems with a Ravenheat LS-100T Combi boiler. From some of the posts and forums I've looked at these boilers don't seem to well thought of. I'm maybe discovering why!

The fan starts up and the boiler fires ok. Pump seems to be turning ok. The TRVs are all open fully.

After about 25 seconds the pressure on the gauge has risen from 1.5 to

2.0 bar and the pressure relief valve opens up and shuts the system down - even though the manual states that the valve is set to operate at 3.0 bar!

These symptoms happen in both central heating and hot water mode.

Anyone got any ideas about a solution?

[Doctor Drivel]

Sounds like the pressure vessel needs recharging or replacing.

[Ed Sirett]

See the Sealed CH FAQ. Probably got a tired valve aswell as failed expansion vessel.