Worcester Bosch Juniour 28i losing pressure

[w88mjb]

Hi all

My boiler is 6 months old and keeps losing pressure. If I set to 1.5 bar, within 4 days it is back to zero.

1) checked all rads & pipework- no leak.

2) No water leaking outside - so not PRV issue

3) Having Expansion vessell pressure checked next week.

Presuming EV pressure ok, what else could it be ?

Could it be a leak of heating system water into the dhw side?

Worcester Bosch will come and check it as in warrenty, but im not happy with "it must be a leak in your pipework" argument, as lost pressure with old ferroli boiler, and pipework exactly the same!

Can any one offer any other potential solution?

 

[w88mjb]

Sorry, meant to say old Ferroli NEVER lost any pressure with same pipework!

 

[swbjackson]

Water won't leak from the heating side to the DHW side. Try topping the pressure up and then isolating the boiler from the system. If the pressure drops it is a problem with the boiler, if it doesn't but drops when the valves are opened again the problem is with the system.

It could be that when the system was flushed it has exposed a weak point in the pipework.