pressure

[buff]

hi i have a basi combo boiler i have just flushed the system,i put half a bar water pressure in the system because it should have one bar but for some un known reason it then goes up to 3 bar why is this and is it dangrous

 

[jackthom]

If this is happening as the boiler heats up it is the expansion pressure vessel which needs attention.

//www.diynot.com/forums/viewtopic.php?t=37170&postdays=0&postorder=asc&start=2

 

[buff]

no it rises overnight to 3 bar and stays there what should i do thanks

 

[mickyg]

Boiler pressure rises only when heating is on = Expansion vessel as above

Boiler pressure rises even with heating turned off =
Likely- Filling loop is passing(remove filling hose to check)
Possibly- Plate heat exchanger is holed(isolate water to boiler over timed period to check)

 

[buff]

thanks i ill check hope its not expensive i just took out the hot water heat exchanger and cleaned it i thought i was all done lol