BoilerFaultCodesTechnical description
High temperature zone room thermostat intervention
What causes this fault?
This fault occurs when the boiler's internal safety sensors detect that the unit has exceeded its safe operating temperature limit. The most common reasons for this include a lack of water flow, a blockage in the heat exchanger, or a pump that has failed or become stuck. As a precaution, the system shuts down immediately to prevent damage to the internal components.
This fault is more frequent when the heating is first turned on in autumn, as pump components can seize up after being inactive throughout the summer.
Engineer required
This is a high severity fault. Stop using the boiler and call a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.
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