BoilerFaultCodesYour boiler is notifying you that it has successfully transitioned to its second, higher stage of heating output.
This 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 signal stage 2
What causes this fault?
This code is not actually a fault, but a status update showing your boiler has increased its heat production to meet a higher demand. It occurs when your heating system realizes the building needs more warmth than the initial low-power setting can provide. The boiler is simply communicating that it has opened its gas valve further to run at full capacity.
This notification is more likely to appear during the winter months when outdoor temperatures drop and your home requires maximum heat output to stay warm.
DIY fix possible
This fault may be fixable without an engineer. Check your manual first.
Find a Gas Safe engineer
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A boiler cover plan would cover faults like 4-5 — no call-out fees, no surprises.
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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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