Vokera Compact HE range intermittent hot water

[Rich S]

The venturi is prone to partial blockages. The boiler will work fine on C.htg but when hotwater is running with maximum burner pressure the burner will drop out and run through the ignition sequence. You can prove this by opening the combustion chamber slightly, the boiler should then run with no problem.

Remove the screws securing the flue hood and the clamp with the recouperator. Draw the flue hood forward so you can see the venturi inside the fan. Remove the venturi from the fan. The best thing to clean the venturi is a pipe cleaner. There maybe only a small amount of dust or debris inside the venturi but this will be enough to drop the air pressure out on max burner pressure.