BoilerFaultCodesYour boiler has repeatedly failed to maintain a flame while running, causing it to shut down for safety.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Ionisation signal loss during operation (after 4 restarts during 1 heat demand)
What causes this fault?
This fault occurs when the boiler successfully starts but cannot keep the flame burning steadily while it is running. The most common reason is that the internal sensor, which monitors the flame for safety, has become dirty or worn out and can no longer detect the heat. It can also be caused by an incorrect mixture of gas and air preventing a stable flame from sustaining itself.
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 77 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Remeha Selecta 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.