BoilerFaultCodesTechnical description
Return sensor temperature exceeded
What causes this fault?
This fault occurs when the boiler detects that the water returning from your radiators is nearly as hot as the water leaving the unit, meaning heat isn't being transferred into your rooms. The most common reasons are a blockage in the system, a failing pump that isn't moving the water fast enough, or a faulty sensor providing an incorrect temperature reading.
This issue is more common when turning the heating back on after summer, as pump components can seize or sludge can settle during long periods of 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.
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