feroli modena 80e boiler loses pressure slowly when running

[sellburn]

feroli modena 80e boiler has started to lose pressure slowly when i run the hot water i have to put pressure up every morning .Upto now i think it could be the blow off valve or expansion cylinder but not sure.anybody got any ideas.
regards Sellburn

 

[bobw1956]

Have you checked the PRV (blow off valve) where it terminates outside,
is there any water dripping from the pipe?

Is the pressure gauge increasing, before you have to top the system up again?
if so then the expansion vestle requires repressurizing/replacing

Are you sure you are losing pressure when you are running the hot water?

 

[kevindgas]

check pressure relief pipe outside isn't dripping if it is dry then sadly you are most likely looking at a new heat exchanger would suggest you don't bother and get the boiler replaced. the Glowworm betacom is almost a direct replacement (changed one recently in 4 hours excluding the flush time)