BoilerFaultCodesGrant DHW PUMP (FLASHING) Fault Code
Also written as DHWPUMPFLASHING — same fault.
The Grant DHW PUMP (FLASHING) fault code means: your boiler is struggling to detect the temperature of your hot water supply, which means it will likely stop heating your water until a faulty sensor or internal control board is replaced.. It appears on 6 Grant models in our database.
Technical description: Indicates either a ‘Store’ thermistor or PCB fault.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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Grant models that show the DHW PUMP (FLASHING) fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Grant DHW PUMP (FLASHING) fault code information on this page is sourced and cross-checked against the official Grant service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 7 July 2026