pressure rising with Biasi Prisma 24SE

[johjoh]

Last week, having bled my radiators, I repressurized my Biasi Prisma Combi Boiler 24SE. At first, not remembering how to do it, I fiddled with the two red valves under the boiler (one on the left and one on the right) and fully opened them.

I've just noticed that the bar is reading 2.6. Is there a simple way to adjust this or should I get a plumber in?

 

[gas4you]

Look for a drain off point under the boiler, or beneath a downstairs radiator.

Put a hose on this and drain into a bucket until pressure drops down to just over 1 Bar cold.

 

[johjoh]

Many thanks, I attached a hose and drained off a little water to get the black bar reading down to 1. Unfortunetly, probably because of my fiddling with the two red wheels (stopcocks?) under the boiler last week, I think I've really messed things up because as soon as I put the heating back on, the black bar reading started to rise to 2.

Should both those red wheel valves be fully open? (turned all the way anti-clockwise).

 

[Agile]

IF they are in series with the CH flow and return which are the left and right pipes under the boiler then they should be fully open, anticlockwise!

If they are connected to anything else then I cannot say with any certainty.

It sounds as if your boiler is either very early, pre 1998, or has not been fitted with the originally supplied valves.

Tony