Combi Boiler Pressure Rising

[captaincaveman]

Hello,
I have a worcester bosch combi boiler which is about 10 years old, no matter how many times i bleed the radiators the pressure slowly creeps up again!
Your thoughts gratefully received.
Many thanks.

 

[kevplumb]

first check the filling loop is disconnected

View media item 11214

 

[ianniann]

If it creeps up gradually whether the boiler is on or off, then the filling loop is passing a small amount of water.

If it goes up too much when the boiler is on, the expansion vessel has run out of air.

 

[twgas]

Some worcesters have an internal filling loop so you may not have one like kevplumb's.
It is possible that the HW heat exchanger has failed, some worcesters have a single, dual flow type and some use a secondary one.

 

[adlplumbing]

op what type boiler is it

 

[daneski88]

op what type boiler is it

It's gas

 

[captaincaveman]

If it creeps up gradually whether the boiler is on or off, then the filling loop is passing a small amount of water.

If it goes up too much when the boiler is on, the expansion vessel has run out of air.

when i disconnect the old filling loop, can i expect to lose a lot of water from the boiler end?

 

[adlplumbing]

turn your stop tap off first then disconnect the turn stop tap on little and see if water comes out

 

[adlplumbing]

op what type boiler is it

It's gas

could be eletric

 

[PEDANTICVINDICTIVEMAN]

If it creeps up gradually whether the boiler is on or off, then the filling loop is passing a small amount of water.

If it goes up too much when the boiler is on, the expansion vessel has run out of air.

when i disconnect the old filling loop, can i expect to lose a lot of water from the boiler end?

Only if the non return valve is faulty and not shut itself off, which can happen.