BoilerFaultCodesYour boiler is struggling to detect the temperature of your hot water cylinder, which usually means the system cannot heat your water correctly.
Book a Gas Safe engineer within 24–48 hours. Your boiler may be unsafe or could break down completely if left.
Technical description: Tank probe damaged
What causes this fault?
This fault occurs when the communication between your boiler and the hot water cylinder is broken, meaning the boiler no longer knows how hot your water is. The most common reason is that the internal components of the temperature probe have worn out or the electrical wiring connecting it to the boiler has become loose or damaged.
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 203 — 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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