Boiler
113
Error code 113 on a Potterton boiler signals a flame detection fault — the boiler is either failing to ignite or losing its flame during operation. This is a lockout fault that stops the boiler running as a safety precaution, so it needs prompt attention.
What does this error mean?
The 113 code means the boiler’s control board has detected that the burner flame went out unexpectedly, or failed to establish at all during a firing attempt. The boiler locks out to prevent unburned gas from accumulating, which is a built-in safety response. Until the underlying cause is fixed, the boiler will continue locking out even after a manual reset.
Est. repair cost
£150–£350 for professional repair (electrode, flame sensor, or gas valve replacement); full boiler replacement £1,800–£2,800 installed
🔍 Likely causes
🛠️ Step-by-step fix
Press the reset button (usually marked with a flame or reset symbol) and hold for 3 seconds. Allow the boiler one full ignition attempt — if it fires and runs normally, monitor it closely over the next 24 hours.
Check your gas supply: confirm other gas appliances in your home (hob, gas fire) are working. If they are not, contact your gas supplier — there may be a supply interruption in your area.
Check the gas isolation valve on the pipe directly behind the boiler is fully open (handle in line with the pipe, not across it).
If the boiler locks out again after a reset, do not attempt further resets beyond three tries in quick succession — repeated failed ignitions can allow gas build-up.
Do not attempt to inspect, clean, or replace the ignition electrode, flame sensor, gas valve, or any internal components yourself. These are gas appliance internals and must only be worked on by a Gas Safe registered engineer.
Call a Gas Safe registered engineer and tell them the boiler is showing fault code 113, locking out on ignition, and how many reset attempts you have made.
📞 When to call a professional
Call a Gas Safe registered engineer if the boiler locks out again within 24 hours of a reset, or immediately if you smell gas at any point. Tell the engineer it is a Potterton boiler displaying error code 113 and describe whether it fails to ignite at all or cuts out shortly after firing — this helps them diagnose faster. Do not attempt to open the boiler casing or touch internal components under any circumstances.
⚖️ Repair or replace?
Most 113 fault repairs — replacing an ignition electrode, flame sensor, or gas valve — cost between £150 and £350 including parts and labour at UK market rates. If your Potterton boiler is over 10–12 years old and requires a gas valve or PCB replacement, the repair cost can approach or exceed the value of the boiler, making replacement the smarter financial decision. A new A-rated combi boiler typically costs £1,800–£2,800 fully installed, but you gain improved efficiency, a new warranty, and lower running costs.