Broag Avanta range with vertical flues E4/E5 fault

[Rich S]

Boiler will intermitantly give E4/E5 during hot water demand.

Installers can push the flue too far into the flue connector on top of the appliance, this then pushes the centre exhaust duct so its nearly touching the top of the heat exchanger so partially blocking the flue outlet. This will usually only lockout during a hot water demand due to the increased volume of products from the higher fan speed.

To check for this without dismantling the flue- Unscrew the combustion test point and insert a screwdriver if it hits the exhaust duct after 40mm then the exhaust duct has been inserted too far and the flue will need to be dismantled and problem rectified.