High
Burner lock-out on Grant Vortex 15-20

Your boiler has detected a temporary issue with the burner and has safely shut itself down to prevent any damage.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Call an engineer soon

Book a Gas Safe engineer within 24 to 48 hours. Your boiler may be unsafe or could break down completely if left.

What the manual says

Manufacturer manual

If there is a burner malfunction, a built-in safety circuit switches the burner off and the 'Lock-out' reset button on the burner will light. Usually such malfunctions are short lived and pressing the red reset button will restore normal operation.

From this model's manual
Verified against the Grant/Grant Vortex 15 20 installation & service manual.
Plain-English guidance below. Severity, DIY steps, costs and parts are our interpretation to help you act, not text from the manual.

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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All 12 fault codes on the Vortex 15-20

Seeing a different code? Every code this model can display, in one place.

26.036.0Boiler operating on overheat thermostatBoiler will not startBurner pulsatesCombustion fumes smellFlame slow to stabilise during start upFumes and puffing during startingOil odoursVisible smoke from flue or high smoke numberWater temperature low

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