Combi boiler losing pressure

[LionelLazenby]

Hello all,
Halstead Finest Gold combi.
I've got a problem with the above boiler.
I set the cold pressure to 1 bar, then when the central heating comes, on the pressure rises very high... >3 bar.
This causes the pressure relief valve to open (I assume) and water drips from the overflow.
When the central heating then cools, the pressure has dropped to 0.5 bar.
I assume it is not good to run the central heating at this pressure?
I also sometimes get a "Safety Lockout" warning light - meaning the boiler must be power-cycled.
Any advice?
Thanks
LL

 

[gas4you]

Search on here for re-pressurising an expansion vessel.

It ahs either lost its pressure or if water comes out of the 'tyre' valve it is knackered and needs replacing.

 

[LionelLazenby]

Great - thanks very much.