BoilerFaultCodesYour boiler's internal computer has developed a fault and can no longer talk to the rest of the system.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Internal fault (PCB)
What causes this fault?
This fault occurs when the boiler's main control board suffers an internal electronic failure or a loss of communication with its connected sensors. It is usually caused by aging electrical components on the circuit board wearing out or, in some cases, a loose connection in the internal wiring harness. Because the 'brain' of the boiler can no longer process safety data, it shuts down the system entirely to prevent accidents.
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 E03 — no call-out fees, no surprises.
Affiliate links — we may earn a commission at no extra cost to you.
Vokera Pinnacle 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.