Low Warning
HC-01 on Daikin D2CND

Your boiler has a fault with the thermometer that measures hot water temperature, meaning your hot water may be unreliable although your heating should still work.

Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed

Monitor it

This is a minor fault. Keep an eye on it and mention it at your next annual boiler service. Reset the boiler and see if it clears.

Technical description

Domestic hot water (DHW) temperature sensor error. The boiler will continue to operate but you need to Contact a heating engineer

What causes this fault?

This fault occurs when the sensor responsible for monitoring the temperature of your tap water fails to send a consistent signal to the boiler's control board. The most common reason is that the internal thermistor has worn out over time or a small amount of corrosion has developed on the electrical connections. Without this data, the boiler cannot safely judge how hot to heat your water, leading to the error message.

Engineer required

This fault requires a Gas Safe registered engineer. Do not attempt gas-related repairs yourself.

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