vokera linea 24

[sadbutcute]

could anyone out there offer any advise on this

i have this boiler that runs hot water perfectly but when i set it for heating it starts ok then increasers the pressure rapidly then drops the pressure right down to zero within an hour hence it locks out. after refilling and restarting the same fault accures.
any help or magic wands would be appreciated
cheers

 

[kevplumb]

search on expansion vessel

 

[sadbutcute]

how would i test this and where is it.
thanks
notrightbright

 

[kevplumb]

back of the boiler
bright red (usually)
isolate and drain the boiler check pressure at the valve (car type) on the top

beetween .5 & 1 bar (dont have the figs to hand)

 

[Agile]

Before you drain the boiler, momentarily depress the pin of the Scroeder valve. You should get a little air out but if any water drops come out then it is almost certainly failed.

Next depressurise the water in the boiler and leave a vent open. Check the air pressure and it should be about 66% of the normal working pressure. Normal working pressure is usually 1.5 Bar so pressurise to 1 Bar or 13.5 PSI. It is essential that this is done with the boiler water side open to the air AS you are pumping.

A diligent engineer would check the operation of the expansion vessel during a service. This is easy to do by noting the increase in system pressure from cold to hot. This typically increases from 1.5 bar to about 1.8 bar but the exact figure varies according to the size of the radiator systems. An excessive increase indicates that the expansion vessel has either failed or requires repressurising.

Tony