Boiler
114
Error code 114 on a Potterton boiler indicates a flame sensor or ignition fault — the boiler has attempted to light but failed to detect a stable flame. This is a lockout fault that prevents the boiler from running, so your heating and hot water will be off until it’s resolved.
What does this error mean?
The 114 code means the boiler’s control board fired the igniter and opened the gas valve, but the flame sensor (also called an ionisation probe) did not confirm a sustained flame within the permitted time window. As a safety response, the boiler locks out to prevent unburned gas from accumulating. The fault can be intermittent or persistent depending on the root cause.
Est. repair cost
£100–£250 for a Gas Safe engineer repair (part + labour); new boiler installation £1,800–£3,000
🔍 Likely causes
🛠️ Step-by-step fix
Step 1 — Reset the boiler: Press and hold the reset button (usually marked with a flame or ‘R’ symbol) for 3–5 seconds. Wait 2 minutes and see if the boiler fires up successfully. This alone clears a one-off ignition glitch.
Step 2 — Check your gas supply: Make sure other gas appliances (hob, gas fire) are working. If they’re not, contact your gas supplier — there may be a supply interruption in your area.
Step 3 — Check the gas service valve: Locate the isolation valve on the gas pipe feeding the boiler (usually a lever near the boiler). Ensure it is fully open — the handle should be parallel to the pipe.
Step 4 — Try a second reset after 10 minutes: If the first reset failed, wait 10 minutes and try once more. Some Potterton models require the overheat thermostat to cool before relighting.
Step 5 — If the fault persists after two resets, stop here: Do not attempt to open the boiler casing, adjust the gas valve, or clean internal components yourself. All further diagnosis and repair must be carried out by a Gas Safe registered engineer.
📞 When to call a professional
If the boiler re-locks with error 114 after two reset attempts, call a Gas Safe registered engineer immediately — do not keep resetting, as repeated failed ignition attempts are a safety risk. Tell the engineer you have a persistent 114 lockout fault on a Potterton boiler and that other gas appliances are working normally (or not, if applicable). They will test gas pressure, inspect the ignition electrode, ionisation probe, gas valve, and PCB to pinpoint the fault.
⚖️ Repair or replace?
A Gas Safe engineer call-out and repair for a 114 fault typically costs £100–£250 depending on the part required — an ionisation probe or electrode is at the cheaper end, a gas valve or PCB at the higher end. If your Potterton boiler is over 10–12 years old and requiring repeated repairs, replacement with a modern A-rated combi boiler (typically £1,800–£3,000 fully installed in the UK) is almost always better value. For a boiler under 8 years old in otherwise good condition, repair is the right call.