How much does it cost to fix Grant error code Flow temperature low?

Typical repair cost for the Grant Flow temperature low fault is £90-250 including labour.

Flow temperature low High

Grant Flow temperature low Fault Code

Q: What does the Grant Flow temperature low fault code mean?

Your boiler is failing to reach the required temperature for heating your home, likely because of a setting issue or a buildup of soot inside the unit.

Also written as FLOWTEMPERATURELOW — same fault.

The Grant Flow temperature low fault code means: your boiler is failing to reach the required temperature for heating your home, likely because of a setting issue or a buildup of soot inside the unit.. It appears on 1 Grant model in our database.

Technical description: Boiler thermostat is set too lowBoiler thermostat faultyBoiler is underfiredCombustion setting of burner incorrectBoiler heat exchanger is sooted up

Typical repair cost £90-250 (including labour)

DIY fix possible

Check the thermostat dial on the boiler control panel and ensure it is turned up to a high enough setting.Check your room thermostat is calling for heat.Ensure there is enough oil in your storage tank.

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Grant models that show the Flow temperature low fault code

Click a model for the full fault code list and model-specific repair notes.

Vortex Blue Repair: £90-250

Source

Grant Flow temperature low 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 27 April 2026