A63 / A64 / F66 High
Your boiler's main internal computer has developed a serious communication or hardware fault and cannot control the system safely.
Technical description: Controller DBM12 fault
Typical repair cost: £250-£450 (including labour)
Engineer required
This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
Protect yourself from future repair bills
A boiler cover plan would cover faults like A63 / A64 / F66 — no call-out fees, no surprises.
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Parts commonly replaced
- Main PCB (Control Board)
- DBM12 Controller
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