Error F.61

Safety precautions:

1. If you smell gas or suspect a leak, do not touch the boiler. Evacuate everyone from the building immediately and call the gas emergency number. In the UK call 0800 111 999. If you are outside the UK call your local gas emergency service.

2. Do not open the boiler casing, attempt to dismantle gas components, or bypass any safety devices. Work on gas valves, the PCB or internal wiring must be done by a qualified Gas Safe engineer.

3. Turn the boiler off at the electrical isolator switch if you need to remove power for safety while performing basic external checks.

Initial checks a homeowner can safely do:

1. Note the exact error code, when it appeared and whether any other error codes are present. Record the boiler model, serial number, age and date of last service.

2. Check the gas supply: verify other gas appliances (cooker, gas fire) are working to confirm the household gas supply is on. If multiple appliances fail, contact your gas supplier.

3. Check that the gas isolation valve to the boiler (if externally accessible) is open. Only operate valves you know and can reach; do not force valves.

4. Check the boiler display and controls for a clear reset instruction. On Vaillant boilers the reset is usually the flame icon with a cross. You may try a single reset as described below.

Safe reset procedure (one attempt only):

1. Turn the boiler off and allow it to cool for a few minutes according to the handbook.

2. Press and hold the reset button (refer to your manual for exact button and method) for up to 10 seconds. Release and wait to see if the boiler fires and returns to normal operation.

3. If the F.61 code clears and the boiler runs normally, monitor it closely. If the fault recurs, do not repeatedly reset; book a Gas Safe engineer.

4. If the fault remains after one reset, switch the boiler off at the isolator and arrange for professional service.

Basic visual checks you can do without opening the boiler:

1. Look for obvious external signs of damage, corrosion or loose connectors on any wiring you can access externally (for example plug-in connectors to external controls). Do not remove panels or probe inside the casing.

2. Check for signs of recent water ingress or leaks near the boiler that might have affected wiring or the PCB. Note any damp or corrosion and report it to the engineer.

Information to prepare for the engineer (helps diagnosis):

1. When the fault first appeared and any patterns (intermittent, after a service, after power cuts).

2. Whether the boiler worked after a reset and for how long.

3. Any unusual sounds, smells, or behaviour (e.g. clicking, failure to ignite, visible flame issues).

4. Boiler model, serial number, age, and date of last service.

What a professional will check and possible outcomes:

1. The Gas Safe engineer will safely isolate and test the gas supply, inspect and test the gas valve and its actuator, check the wiring harness and connectors for continuity and earth/short faults, and carry out PCB diagnostics. They will also check for any symptoms of PCB component failure (for example failing electrolytic capacitors on older EcoTEC PCBs) and test relevant sensors.

2. Repairs may involve freeing or replacing the gas valve, repairing or replacing wiring/connectors, or replacing/repairing the PCB. The engineer will use appropriate test equipment and follow gas-safety procedures.

Final notes and warnings:

1. Do not attempt to repair the gas valve, replace the PCB, or modify internal wiring yourself. These are gas and electrical safety critical repairs.

2. If the F.61 code appears repeatedly or the boiler will not run after a single safe reset, arrange an appointment with a Gas Safe registered engineer promptly. Continued use without a proper repair risks unsafe operation and loss of heating and hot water.

3. Keep up with regular annual servicing to reduce the likelihood of valve, PCB and wiring faults and to help catch intermittent issues early.