hi evryone, just tying to confirm plumbers prediction on my vokera compact 28 non condensing combi, i have a steady trickle of water passing through blow off outside, as pressure builds to 3 bar, 15 to 30 seconds after comisioning. i have already replaced filling loop to no availe before calling plumber, and building society (for new mortgage) any help would be greatley appretiated thank you
vokera boiler pressure build up
- Thread starter brettster
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Turn the cold supply off to the boiler and see what happens. If the problem disappears then its likely to be the heat exchanger has failed internally and is allowing mains pressure into the primary side. If that is the case then new heat exchanger required.
Can't recall if these have a secondary or a twin pass exchanger, but I would bet on it being a twin pass and therefore not cheap.
Can't recall if these have a secondary or a twin pass exchanger, but I would bet on it being a twin pass and therefore not cheap.
thanks for reply 45years, your susspisions are correct, these boilers do not have secondary heat exchanger, is there any chance it could be pressure releif valve itself many thanks
If the pressure builds to 3 bar with the boiler OFF, then it is the heat exchanger. Do the test I suggested with the boiler off.
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If its not the filling loop its defo the heat exchanger.
Can someone explain what a twin pass HE is, please? 
thanks once again will try test on monday and keep informed
Quote---Can someone explain what a twin pass HE is, please?
I'm sure you know.............Or do you?
I'm sure you know.............Or do you?
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