BoilerFaultCodesTechnical description
Return temp > flow temp: Flow sensor badly installed; Pump operating in wrong direction or flow and return connections crossed
What causes this fault?
This fault occurs when the boiler's internal sensors detect that the water returning from your radiators is hotter than the water leaving the boiler. This usually means the water is physically being pushed the wrong way through the system or a sensor has failed and is sending incorrect data to the control board. It is often triggered by a failing pump or a blockage that has forced the water to circulate in reverse.
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 →