BoilerFaultCodesTechnical description
Diverter valve by Grundfos
What causes this fault?
This fault occurs when the internal motor fails to move the valve into the correct position to send heat where it is needed. The most common reason is that the mechanical components inside the valve have become stuck due to a buildup of debris or wear and tear, preventing the motor from completing its cycle. This results in the boiler being unable to differentiate between heating your home and warming your water.
This fault is more frequent during the autumn and winter months when the boiler is regularly switching between heating and hot water demands after a period of summer inactivity.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.