Boiler
119
Error code 119 on a Potterton boiler indicates a flame loss fault — the boiler has attempted to ignite but cannot detect or sustain a flame. This is a safety lockout and should not be ignored.
What does this error mean?
The boiler’s control board fired the ignition sequence but the flame sensor (ionisation probe) failed to confirm a stable flame within the allowed time window. As a safety measure, the boiler locks out to prevent unburned gas from accumulating. You’ll typically see the 119 code on Potterton Promax, Profile, and Performa models.
Est. repair cost
£80–£250 for a Gas Safe engineer repair (part + labour); PCB replacement up to £400–£500
🔍 Likely causes
🛠️ Step-by-step fix
Check your gas supply first: confirm other gas appliances (hob, oven) are working. If not, contact your gas supplier immediately — do not attempt to reset the boiler.
Check your prepayment meter (if applicable) has sufficient credit and has not gone into emergency credit.
Press and hold the reset button on your Potterton boiler for 3–5 seconds until the error clears, then wait to see if the boiler fires successfully. Refer to your model’s manual for the exact reset procedure.
If the boiler locks out again after 1–2 reset attempts, stop resetting. Repeated failed ignition attempts without a confirmed fix can be unsafe — call a Gas Safe registered engineer.
Do not attempt to inspect, clean, or replace the igniter, ionisation probe, gas valve, or burner yourself. These are Gas Safe-regulated tasks and illegal to carry out without registration.
📞 When to call a professional
Call a Gas Safe registered engineer if the boiler re-locks after one or two resets, or if you cannot confirm the gas supply is reaching the boiler. Tell them you have a Potterton error code 119 (flame loss lockout) and approximately how many times you have reset it — this helps them diagnose the fault faster on arrival.
⚖️ Repair or replace?
A Gas Safe engineer call-out and repair for a 119 fault typically costs £80–£250 depending on the faulty component — an ionisation probe is cheap; a PCB or gas valve is more expensive. If your Potterton boiler is over 10–12 years old and facing a repair bill above £400, replacement is usually better value. A new combi boiler installed in the UK costs £1,800–£3,500 fully fitted.