Thermostat shows E17 and time/date keep resetting

Safety first: No internal component replacement is recommended for end users.

Steps:

• Ensure the thermostat has a stable power supply and is not on a switched spur that is turned off regularly.
• Connect the thermostat to the Heatmiser app or NeoHub so that time can be synchronised automatically from the internet.
• Perform a factory reset and firmware update if available.
• If E17 persists and the clock resets after every power cut, the internal RTC or backup storage has failed and the thermostat should be replaced.