BoilerFaultCodesYour boiler’s internal computer has encountered a software error while checking its settings, which has caused the system to stop working 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: Parameter CRC fault – try resetting the boiler
What causes this fault?
This fault occurs when the boiler's internal computer detects a data corruption error between its main memory and the settings plug. It essentially means the boiler can no longer verify its own configuration, so it shuts down as a safety precaution to prevent running with incorrect instructions. The most common reason is a failing main circuit board or a loose electrical connection at the parameter plug.
DIY fix possible
Locate the power switch or fused spur for the boilerTurn the power off for 30 secondsTurn the power back on and press the 'Reset' button on the display panelMonitor the boiler to see if the error screen clears
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 E1-69 / E1-70 — no call-out fees, no surprises.
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Could it be time for a new boiler?
If repair costs are adding up, a new energy-efficient boiler could be the smarter long-term choice.
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