D4 213 High
Your boiler is heating up too quickly, which usually means the water inside is not circulating properly or the system is low on pressure.
Technical description: The actual temperature recorded by the flow temperature sensor or return temperature sensor is rising too quickly
Typical repair cost: £120-280 (including labour)
DIY fix possible
Check the system pressure gauge and top it up to 1.5 bar if it is too lowEnsure all radiator valves are fully open to allow water to flowBleed all radiators to remove trapped air that might be blocking circulation
Protect yourself from future repair bills
A boiler cover plan would cover faults like D4 213 — no call-out fees, no surprises.
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Parts commonly replaced
- Circulation Pump
- Flow/Return Temperature Sensor (NTC)
- System Filter (Cleaning)
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