vokera 28 pressure

[MrB.]

Hello, I have the above combi and the pressure sits just below the red marker at the top end of the pressure gage.
When i use the little button underneath to reduce the pressure, takes about an hour but it goes straight back up there.

The little black filler tap underneath seems to be completey shut off.

The heating and hot water work fine.

Any ideas would be appreciated.

 

[nickso]

have you removed the hose to confirm the tap is indeed completely closed and not passing?

 

[ajrtd]

You may find its the PHE. Domestic hot water heat exchanger, the plates split and cause the system pressure to rise and PRV to operate.

 

[MrB.]

i have removed the pipe and there are no leaks.

How dangerous is this and would it be cheaper to buy a new boiler or get it repaired.

 

[nickso]

i have removed the pipe and there are no leaks.

How dangerous is this and would it be cheaper to buy a new boiler or get it repaired.

then it must be the plate heat exchanger. not an expensive or difficult job to repair on this model.

 

[MrB.]

Do you need to touch the gas side of the boiler or can it be a diy job?

Also can i repair the part or will it need replaced.

Any idea how much and the best place to get a spare?