Emergency Lockout
LOCKOUT: c on Potterton Housewarmer

Your heater has shut down because it cannot pull in enough fresh air to operate safely, which increases the risk of dangerous carbon monoxide buildup.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Act immediately

Turn off your boiler and stop using gas appliances. Call a Gas Safe engineer now. This fault can be dangerous if ignored.

Technical description

INADEQUATE ROOM VENTILATION

What causes this fault?

This fault occurs when the appliance detects that there isn't enough fresh air entering the room to support safe combustion. The most common reasons are air vents being accidentally blocked by furniture, a buildup of dust and lint in the grilles, or even new home improvements like weather-stripping or double glazing that have made the room too airtight.

This fault is more common in winter when homeowners may inadvertently block air vents to stop cold draughts or keep windows tightly shut for long periods.

Engineer required

This is a emergency severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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Related fault codes

LOCKOUT: bView →LOCKOUT: aView →

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