BoilerFaultCodesYour heater has shut down because it cannot pull in enough fresh air to operate safely, which increases the risk of dangerous carbon monoxide buildup.
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.
DIY fix possible
Check that all purpose-built air vents in the room or walls are not blocked by furniture or decor.Ensure external air bricks or vent grilles are clear of leaves, debris, or snow.Remove any dust or spider webs that may have accumulated over the air intake area.
Find a Gas Safe engineer
Search the official register for a qualified engineer in your area.
Gas Safe Register →Protect yourself from future repair bills
A boiler cover plan would cover faults like LOCKOUT: c — no call-out fees, no surprises.
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Potterton Housewarmer is discontinued — time for a new one?
Parts for discontinued models can be hard to find and expensive. A new A-rated boiler could save you money on both repairs and energy bills.
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