Overview
E134 on a Potterton Assure combi/system means the boiler opened the gas valve but the burner did not receive gas within the expected time — the controller timed how long the valve was open and detected no gas flow. The code often appears when there are short, repeated ignition attempts where the control expects to see gas/ignition quickly but does not. Typical root causes include an interruption to the house gas supply, a closed or faulty gas isolation valve, a gas valve wiring or command fault, or internal ignition/gas delivery issues in the boiler. This fault is safety-critical because it involves the gas supply and ignition system. Some basic checks can be done by the homeowner (see troubleshooting below), but you should not open or work on the gas valve, burner, gas pipework, valve wiring or PCB unless you are a Gas Safe registered engineer. If the fault persists after simple checks, or if you smell gas, evacuate and call your gas emergency number and a Gas Safe engineer immediately.
Possible Cause: Elapsed time gas valve open without gas
Troubleshooting Steps
Safety first:
- If you smell gas (rotten egg smell or a strong gas odour), do not operate electrical switches, do not use phones inside the property, open windows and doors, evacuate everyone from the building, and call the gas emergency number immediately. Do not attempt any checks in that situation.
- Turn off the boiler and isolate electrical power using the external switch or the boiler isolation switch before any non-trivial inspection. Never remove covers or try to access internal components unless you are Gas Safe qualified.
Initial homeowner checks you can do safely:
1. Check other gas appliances (cooker, gas fire) to see if they light. If no other appliance works, it points to a supply issue or house isolation valve problem — contact your gas supplier.
2. Check the external gas isolation valve to the property (usually near the meter) is open if you know where it is and can operate it safely.
3. Check the boiler display and controller history for any additional fault codes (e.g., E09, E15, E133, E135) which can indicate a gas valve wiring/command fault or ignition failure.
4. Try a boiler reset: use the boiler reset button per the manual and hold for the recommended time (typically 3–5 seconds). If the code returns immediately or repeatedly, do not continue to reset multiple times; this can hide a persistent fault.
5. Check system pressure on the boiler display — while E134 is gas-related, low system pressure or circulation faults can sometimes cause unusual behaviour. Ensure pressure is around 1–1.5 bar when cold.
6. In cold weather inspect the condensate discharge pipe (if visible) for freezing; a blocked condensate can cause ignition/lockout symptoms. If frozen, thaw gently with warm (not boiling) water or towels.
Specific diagnostic steps (do not work on gas parts unless qualified):
1. If other gas appliances work and the house gas supply is live, note whether the boiler attempts to ignite when calling for heat or DHW (you may hear the fan/solenoid operate). If you hear the gas valve energise but there is no ignition, this suggests either no gas reaching the burner or a valve/ignition fault.
2. Visually inspect accessible wiring and connections to the boiler for obvious damage or loose plugs. Turn power off first. Re-seat any modular connectors that are accessible and external to the boiler casing.
3. If you have a multimeter and are competent with basic electrical checks, you can check for the presence of control voltages at external connectors only — do not probe inside the gas valve or burner area. If unsure, stop and call an engineer.
4. If E134 follows an intermittent loss of gas supply from outside (supplier interruption) the code may clear after supply restoration and a reset. If the gas supply is steady but the fault repeats, this indicates an internal gas valve, wiring, or PCB/ignition module fault that requires an engineer.
5. Record the pattern: does E134 occur only on initial ignition, on every call for heat, or after a certain number of short requests? This information helps the engineer diagnose intermittent supply vs internal fault.
When to call a professional:
- If resetting does not clear the fault or it keeps recurring, stop further DIY work. Contact a Gas Safe registered engineer. E134 implicates gas delivery and ignition hardware which are legally and practically the domain of qualified engineers.
- If additional fault codes related to gas valve wiring (E09/E15), ignition failure (E133), internal gas supply interruption (E135), or PCB errors appear, call a Gas Safe engineer.
- If you detect a gas smell or suspect a leak, evacuate and call the gas emergency service immediately.
What the engineer will likely do:
- Verify external gas supply and isolation valves, test gas pressure, inspect gas valve operation and wiring, run safe ignition and flame detection tests, and check the ignition module and PCB for faults. They may also check for blocked flue/venting or frozen/blocked condensate that can contribute to ignition faults. Any replacement of gas valves, burners, or PCB/ignition modules must be performed by a qualified engineer.
Practical notes for the homeowner:
- Do not repeatedly reset the boiler to force it to run — repeated resets mask persistent faults and can be unsafe.
- Note the time/date and circumstances when the fault occurred and any other boiler codes or symptoms; this helps the engineer diagnose faster.
- Keep the boiler manual and the engineer’s details handy for service calls.
Helpful Resources
Boiler Manual
Download the official PDF manual for the Potterton Assure Combi and system.