BoilerFaultCodesYour boiler has shut down because a safety sensor has detected that it is getting too hot or that there is an issue with the gas supply pressure.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Safety input blocked (e.g. gas pressure switch / heat exchanger thermostat)
What causes this fault?
This fault occurs when one of the boiler's crucial safety sensors detects an unsafe operating condition, such as the heat exchanger reaching an excessive temperature or the gas supply pressure dropping too low. It acts as a protective shutdown to prevent internal damage or unsafe combustion. The most common trigger is either a genuine circulation issue causing the unit to overheat or a faulty sensor sending an incorrect signal to the control board.
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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 E39 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Remeha Avanta Plus 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.
Affiliate links — we may earn a commission at no extra cost to you.