BoilerFaultCodesTechnical description
Central heating return temperature is greater than90°C
What causes this fault?
This fault occurs when the water returning to the boiler is too hot, which happens when heat cannot be transferred away into your radiators effectively. The most common reasons are a pump failure that has stopped water from moving, or a blockage caused by a build-up of sludge and debris in the pipework.
This fault often appears during the first cold spell of autumn when the heating is turned back on after being idle all summer, which can cause internal pump components to seize.
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.
Find a Gas Safe engineer
Search the official register →