Pressure Variation

[diyscotland]

I have finally managed to fix a leak in my combi central heating system and restore pressure properly. I re-set the pressure, when cold, to about 0.75 bar as per manufacturers instructions.
Now when the system heats up I get a large increase in pressure, to over 3 bar at full temperature.
Thinking it may be air in the system I bled all the radiators, but still the vast change in pressure between cold and hot.
Is this normal, or is there an other problem I have to resolve?

It is a Vokera 28
No air released when bled
Did not drain whole system to sort leak

Thanks

 

[Al-Glasgow]

Did you drain the full system after the repair ?.

did you remove air when you bled the rads ?, or just water ?.

btw whats the combi we are talking about ?.

Alan

 

[diyscotland]

Did you drain the full system after the repair ?.

did you remove air when you bled the rads ?, or just water ?.

btw whats the combi we are talking about ?.

Alan

It is a Vokera 28
No air released when bled
Did not drain whole system to sort leak

 

[Agile]

Look in the FAQ section on this forum for instructions on repressurising the expansion vessel.

Its essential that you follow them to the letter otherwise you will end up not doing it properly!

Tony