What the manual says
Manufacturer manualPump over run
What causes this fault?
This occurs when the boiler has finished heating your hot water and needs to move the remaining heat away from the internal heat exchanger. It is a standard safety feature where the pump continues to run for a short period to protect the internal components from heat stress. This is part of the boiler's normal cooling cycle and does not indicate a breakdown.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Avoid the next call-out bill
A cover plan would handle faults like S.27: no call-out fees, no surprise bills.
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Related fault codes
All 77 fault codes on the ecoTEC plus 637
Seeing a different code? Every code this model can display, in one place.