Glow-worm Betacom 24c High Boiler Pressure

[Wheelie1]

Hi,
I recently had problems with my hot water and an engineer came around and removed the plate heat exchanger and cleaned it out along with cleaning the diverter valve. This seems to have solved my hot water issues but I now seem to be having trouble with the boiler pressure going into the red zone (3-4 bar) when the heating is on. This is then leading to the pressure relief valve leaking. I have drained some water from a radiator to reduce the pressure to just over 1 bar but when the heating goes back on the same issue arises.
I would be grateful for any advice.
Thanks

 

[Andyswad]

Pressure vessel needs recharging or replacing, get a gas safe engineer to fix

 

[Wheelie1]

Thanks for the reply.
Engineer actually came today and re-charged the pressure vessel.
All seemed to be working ok but now the pressure is dropping when the heating is off to below 1 bar and there is a low pressure warning light. I've used the filling loop to top back up above 1 bar but it still gradually loses pressure. Any more ideas?

 

[Ermintrude]

How did he drain the boiler off when he recharged....... Red nob

 

[Wheelie1]

He drained it from one of the downstairs radiator drain valves.