5 fault codes with plain-English explanations, severity ratings, DIY guidance, and repair cost estimates.
This boiler uses LED flash patterns
Count the flashes in one repeating group before the pause. That number is your fault code. Do not reset until you have noted it. How to read fault codes →
Tap any card for details
Your boiler has stopped heating because the internal water pump, which moves hot water around your house, has seized up or failed and cannot restart itself.
Your boiler is struggling because the internal water pump is stuck or not receiving power, which prevents heat from circulating through your home.
Your Grant boiler has stopped because the water circulation pump is either jammed or has suffered an electrical failure, meaning your home will not get any heating or hot water.
Your boiler has completely lost power and is unable to turn on, meaning it cannot provide any heating or hot water.
Your boiler has stopped circulating water because the internal pump has jammed, meaning you currently have no heating or hot water.
Not faults — these are normal operating states. Tap to expand.
Monthly cover means no unexpected bills when your boiler breaks down.
Affiliate links. We may earn a commission at no extra cost to you.
BoilerFaultCodes