This fault can involve incomplete combustion and carbon monoxide.
If anyone in the property feels sick, dizzy or drowsy, or you can smell gas: open the windows, leave the building, and do not switch anything on or off. Then call the National Gas Emergency Service.
0800 111 999Potterton E134 fault codewhat it means and how to fix it
The Promax Ultra's timed-out ignition: the gas valve was held open for the whole ignition period and nothing arrived to light. Check the supply, reset once, then call.
Take care
Is gas available at another appliance?
The right answer depends on what you can see. Pick the one that matches.
Choose the option on the left that matches what your appliance is doing, and the answer for that case appears here.
No
Supply, not the boiler.
Check the meter credit and the emergency control valve, then ring the supplier.
Yes
The boiler's own valve or supply pipe.
Engineer to check the valve and the working pressure at the boiler.
What E134 means
The Promax Ultra table has a row the Assure table does not, and it gives 134 to the time that ran out with the gas valve open and no gas behind it. The Assure manuals name 134 only in the sentence that introduces the ignition codes as a group — the one about gas not reaching the burner — and never list it in their table, so on a Potterton the number properly belongs to the Ultra.
The meaning is in the name. The control opened the gas valve for the ignition period, watched for a flame, and reached the end of its allowed time without one; it has counted the valve-open time as gas admitted with no result and stopped. On the Ultra it is on the reset list, a one-to-three-second press.
For an owner the useful distinction is from 133: 134 tends to appear when the supply is genuinely absent or weak — a prepayment meter that ran out, a bulk LPG tank running low, a freshly reconnected supply still holding air — rather than when the ignition parts are worn. The Ultra user guide's general instruction for a code that returns is to contact your installer, annual service provider or Baxi Customer Support.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Nothing arriving at the valve | Credit exhausted, emergency control valve closed, LPG tank empty. The valve opened correctly; there was nothing behind it. | Common |
| Air in the supply after work | Air left in the pipe after a meter swap or an appliance being disconnected. The first few ignition attempts purge it and fail, and the Ultra counts them. | Occasional |
| Gas valve fault | A valve that is told to open but does not pass gas produces the same result. Section F of the fault-finding chart tests the supply to it and then replaces it. | Occasional |
What to try yourself
Check the hob or another gas appliance lights. Check the meter for credit.
Once you know gas is available, press Reset for about a second. After supply work, a second attempt a few minutes later is reasonable while air clears.
If 134 persists with gas confirmed at other appliances, stop and contact your installer or Baxi Customer Support.
Get a Gas Safe registered engineer to look at your Potterton E134
We do not pass enquiries to a repair firm, so there is no form here. Find a Gas Safe registered engineer through the Gas Safe Register, and ask to see their registration card when they arrive — it is the register, not the van, that tells you they are qualified.
What it costs to fix
Typical repair cost
£0–£300
Time on site
5 minutes
Nothing to pay when it was the supply. Gas valve £190–£300 fitted.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Parts you may need
We may earn a commission if you buy a part through one of these links. It does not change what you pay, and it does not affect which parts we list.
Baxi / Potterton / Main gas valve
7683968£120–£240Authorised Baxi parts distributor
Price checked 28 September 2026
Own this appliance and had this code? . Nothing is published until a person has read it.
Related Potterton fault codes
- E133Get it checkedGas supply interrupted, ignition failed or no flame detected — every Potterton generation. Confirm the gas supply, one reset (5 s on the knob, 1–3 s on the button), and call if it returns.Related: ignition and gas supply
- E128Get it checkedFlame failure during normal operation on the Potterton Assure and Promax Ultra: the burner was lit and went out. Resettable; recurring E128 wants an engineer.Related: ignition and gas supply
- E135Get it checkedThe Assure and Promax Ultra's internal-error ignition code: the control blames its own side of the gas valve rather than the supply for the flame that never came. One reset; then an engineer.Related: ignition and gas supply
- E09Get it checkedThe Assure and Promax Ultra's gas valve connection cable fault: the board has lost its wiring link to the valve. Resettable once; recurring 09 is a wiring or PCB job.Related: ignition and gas supply
- Red light flashingGet it checkedPotterton Assure Heat, Titanium Heat and Ultra Heat have no display: the illuminated button flashes red a number of times when the boiler has locked out. The count is the code.Related: ignition and gas supply
- E15Get it checkedThe Assure and Promax Ultra's own-valve code: the board has detected a fault in the gas valve itself, not its cable. One reset allowed; then an engineer with a meter.Related: ignition and gas supply
Own a Potterton boiler? Save it and its codes come first next time.
Related guides
Technical review
Not reviewed by an engineer
No engineer has read this page. Severity follows what the manufacturer publishes, and we would rather tell you that than let a byline imply a sign-off.
Sources and how we verified this
We establish the facts from the sources below and then write the explanation ourselves. We do not copy manufacturer wording and we do not host their manuals.
- Manufacturer technical and service documentation
This page has not been reviewed by an engineer, and we would rather tell you that than imply otherwise. The severity rating follows what the manufacturer publishes: where they say isolate the appliance and call someone, so do we.