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Rick Ridley
Rick Ridley, UK Heating Engineer
Category: UK Plumbing
Satisfied Customers: 1561
Experience:  30 Years on the tools, now retired, Ex CORGI
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I am working on a vokera 25he compact, the boiler only

Customer Question

I am working on a vokera 25he compact, the boiler only lights when I blow down the tubes at the air pressure switch but goes off again when re attached, any advice is welcome
Submitted: 1 year ago.
Category: UK Plumbing
Expert:  Andrew Smith replied 1 year ago.

It sounds like the fan connection is blocked or the venturi is damaged.

Will it work with only the positive pressure tube attached?

Customer: replied 1 year ago.
I've had the venturi out and cleaned it, I have to blow down the tube to get it to start and once it's lit I connect the tube and it stays working for a while. Once the combustion cover is placed back on the boiler goes out
Expert:  Andrew Smith replied 1 year ago.

It sounds like the venturi is not creating enough pressure or the flue is partially blocked or the flue seals are failing.

More likely to be the first point.

Does it work any better with only one tube connected?

Customer: replied 1 year ago.
It does seem to work better with only one tube connected
Expert:  Andrew Smith replied 1 year ago.

Veturi then.

You may find they are both prducing positive pressure

Customer: replied 1 year ago.
The fan isn't running until I blow down the tubes, have phoned vokera and they have recommended new board and thermistor which I have changed but still only pump running
Expert:  Andrew Smith replied 1 year ago.

Perhaps the boiler does not know the pump is running.

Does your model have a ch flow switch?

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