Grant Overheat Cut-Out Thermostat Neon Red MPCBS46

The Grant MPCBS46 is an overheat cut-out thermostat fitted with a red neon indicator, used on Grant oil-fired combi and Vortex boiler ranges. It monitors boiler temperature and interrupts the burner circuit if the appliance overheats, with the red neon providing a visible indication of the trip condition. It is a round-pattern thermostat supplied as a boiler spare.

• The boiler locks out and requires manual resetting, with the overheat trip operating repeatedly.
• The red neon fails to illuminate when the overheat cut-out has tripped.
• The boiler shuts down the burner before the set operating temperature is reached.
• The thermostat or neon shows signs of heat damage, cracking or burning at the terminals.
• Continuity across the cut-out does not change as expected when the appliance is reset.

• Confirm the boiler model and version against the fitment list, as several Grant combi and Vortex variants are covered.
• Check the existing thermostat pattern and the position of the neon indicator.
• Verify the part number MPCBS46 matches the marking on the component being replaced.
• Confirm whether the appliance uses a separate overheat cut-out or a combined control before ordering.