Error S.14

Safety precautions:

- If you smell gas or suspect a leak, do not attempt any checks on the boiler. Turn off the gas supply at the meter (if it is safe to do so), ventilate the area, evacuate the property and call your gas emergency number immediately.

- If you have symptoms of carbon monoxide (headache, dizziness, nausea, flu-like symptoms) get fresh air and seek urgent help.

- Before touching the boiler facia or controls, switch off the electrical supply to the boiler at the fused spur. Do not remove the boiler casing or attempt internal electrical or gas work unless you are qualified.

Initial homeowner checks you can safely do:

1. Note the exact error code and whether it is persistent or intermittent. Take a photo of the display and any additional fault messages.

2. Try a basic reset: switch the boiler off at the fused spur, wait 30 seconds, then switch back on and use the boiler reset procedure as described in the user manual. Some transient faults clear with a reset; persistent S.14 returns indicate further investigation is needed.

3. Check boiler pressure on the display or gauge. If pressure is below about 0.8–1.0 bar, top up the system using the built-in filling loop to about 1.2–1.5 bar and see if the fault clears. Do not over-pressurise.

4. Check external controls: make sure any cylinder thermostat, room thermostat or programmer/timer calling for hot water is set correctly and not stuck in an odd state. Turn off timers/controls briefly to test if the fault is related to a control signal.

5. Listen and look: when calling for hot water try to hear the fan start or any unusual noises. Check the flue termination outside for obvious blockages (leaves, bird nest) but do not insert objects or obstruct the flue further.

Specific diagnostic steps (homeowner-safe) and information for the engineer:

- If reset and basic checks do not clear S.14, do not attempt internal repairs. Prepare information for the engineer: when the fault occurs (on DHW call, intermittently, after power cuts), boiler pressure, any other fault codes logged, and photos of the display and flue termination.

- A competent engineer will: check fault memory and live diagnostics on the boiler, run a fan test and monitor fan speed/impeller sensor signal, inspect wiring/connectors between fan/impeller sensor and the PCB for corrosion, chafing or loose connections, check the condition and operation of the fan/impeller assembly and flue pathway, test the NTC sensors and other safety sensors for plausible readings, and check PCB communication and power supply voltages.

- Possible engineer repairs include cleaning or replacing a faulty fan/impeller, replacing a damaged impeller sensor or wiring, repairing corroded connectors, or replacing the control PCB if it is proven to be faulty. After repairs they will run ignition and safety sequences and confirm stable operation of hot water and safe combustion.

When to call a professional:

- Call a Gas Safe registered (or local competent) heating engineer if the error persists after reset and the simple checks above, if the fan does not run or makes unusual noises, if there are other fault codes present, or if you are unsure. Do not attempt to open the boiler casing or work on gas/electrical components yourself.

Additional advice:

- Keep the boiler serviced annually by a competent engineer to reduce sensor and fan failures. Provide the engineer with the details and photos of the S.14 fault and any steps you have already taken to help speed diagnosis.

- If in doubt about safety at any point (gas smell, poor combustion signs, persistent lockouts), turn the appliance off and call a professional immediately.