Vokera water heater locks out with code 01, burner does not ignite, fan may start briefly then stop

Safety first: Turn off electrical power to the water heater and close the gas isolation valve before removing any covers. If you smell gas, ventilate the area and contact a Gas Safe registered engineer immediately.

Basic checks you can do:

• Reset the appliance: Use the reset button on the Vokera control panel (refer to your model’s manual). If code 01 returns repeatedly, do not keep resetting.
• Check gas supply: Ensure the gas isolation valve under the appliance is fully open and that other gas appliances in the property work normally. If other appliances also fail, contact your gas supplier or a qualified engineer.
• Inspect air inlet and flue terminal: From outside, make sure the flue terminal is not blocked by debris, snow, or nests. Do not insert objects into the flue.

Work for a qualified technician:

• Remove the combustion chamber cover and inspect and clean the main burner using a soft brush and vacuum, ensuring ports are not blocked.
• Check the ignition electrode and flame sensing electrode for cracks, carbon build-up, or incorrect gap; clean or replace as needed.
• Verify correct operation and wiring of the gas valve assembly and measure gas inlet and burner pressure according to Vokera specifications.
• Check the PCB ignition circuit for damage or loose connections.

If you are not qualified, do not remove the combustion cover or work on gas components; contact an authorised Vokera service agent.