Vokera Compact 28

[neogramps]

I need some advice.

I have a 3 year old Vokera Compact 28 combi boiler and the pressure is very odd.

If the system sits cold, the pressure sits at about 0.5 or lower - but when the heating is on, the pressure goes up to 2.0-2.5. If I repressurise to 1-1.5 while the system's cold, when it's running it will go up to 3 and vent pressure through the release valve, and go back to idling at 0.5

Going from 0.5 to 1 when refilling only takes a couple of seconds (like filling a cup of water), so I don't think the whole system is depressurised. All the rads are hot to the top, and heat up quickly, so it's not full of air.

Any ideas what the problem could be?

 

[DP]

get the boiler serviced

 

[45yearsagasman]

Most likely your boilers expansion vessel has lost its charge or the diaphragm is split. See FAQ's for advice on exp vessels

 

[neogramps]

Thanks a lot - I've read up on problems with the expansion vessel, and it seems to fit the symptoms. Engineer coming tomorrow.

Edit - dead on with the diagnosis - expansion vessel was full of water, and a little dirt from the rads (4 years old and never been cleaned/filtered, or recharged during previous services).

Re-pressurized and it's working away quite happily now.