BoilerFaultCodesYour boiler's main internal computer has developed a serious electronic fault and can no longer control the heating system safely.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: PCB Fault. Replace PCB.
What causes this fault?
This fault occurs when the boiler's internal control board suffers an electronic failure, often due to worn-out components or a power surge. It means the software on the board can no longer communicate with the sensors and valves, causing the system to stop working for safety reasons.
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 Red LED: Flash, Green LED 1: On, Green LED 2: Flash — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Potterton Promax 15/2 HE 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.