BoilerFaultCodes dA Medium Warning
Your boiler has lost its connection to the indoor temperature sensor for your main heating area, meaning it cannot accurately tell how warm your rooms are.
Book a service
This fault should be looked at by a Gas Safe engineer within the next week or two. It may get worse if left.
Technical description: Room temperature sensor heating circuit A1 shorted out
What causes this fault?
This fault occurs when the electrical signal from your indoor temperature controller is interrupted or becomes inconsistent. The most common reason is a loose connection in the wiring or a failure of the internal sensor component that detects the heat level in your home.
Typical repair cost £90-180 (including labour)
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.
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A boiler cover plan would cover faults like dA — no call-out fees, no surprises.
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