Monitor itThis is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears. Technical description Operating mode DIY fix possible No action is required as this is a normal display status. Find a Gas Safe engineer Search the official register → Related guides you might find usefulIs boiler cover worth it?Break-even maths on monthly cover.Read →When to replace your boiler7 signs repair isn't worth it anymore.Read →New boiler cost 2026Realistic UK prices for a swap.Read → Recently viewed