Potterton E384 fault codewhat it means and how to fix it
The Assure and Promax Ultra report a flame signal while the gas valve is shut. An electrode or PCB fault, and the Assure manual's answer is to go over the board.
Take care
When does 384 appear?
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.
At start-up, before the burner should light
Electrode or board reporting a flame that is not there.
Engineer.
After a wet spell or a leak from the boiler
Moisture in the chamber conducting the flame signal.
Engineer to find the leak; the code goes when the chamber dries.
What E384 means
The table entry for 384 is a false flame, and it describes a boiler that detected a flame signal at a moment when there should not have been one — before the gas valve opened, or after it closed.
On both the Assure and the Promax Ultra it is on the reset list, so a single one-to-three-second press is allowed, but the Assure System installation manual singles it out, with 09, 15 and 110, for an instruction most codes do not get: when any of the four flashes or keeps coming back, the engineer checks every connection on the board before changing the board itself. That puts 384 in the electronics group rather than the gas group.
A flame signal is a small current through the flame to earth; a sensing electrode that is tracking to earth through soot or a cracked insulator, moisture in the burner compartment after a condensate leak, or a fault on the flame-detection circuit of the board can all produce one without a flame. The Promax and Titanium tables do not have 384; their boards report the condition differently or not at all. The owner's part is small: one reset, and if the code returns, the installer or Baxi Customer Support.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Sensing electrode tracking to earth | Carbon deposits or a cracked ceramic on the combined detection electrode (part 7686344) give a path that reads as flame current. | Common |
| Moisture in the combustion chamber | A leaking condensate trap or heat exchanger seal wets the burner door area; the water conducts. Often follows a period of the boiler being off. | Occasional |
| PCB flame-detection circuit | The Assure manual's remedy for a 384 that keeps coming back: the connections on the board first, then the board. | Occasional |
What to try yourself
Press Reset for about a second and see whether the boiler starts and runs.
If 384 returns, switch the boiler off at the fused spur and contact your installer or Baxi Customer Support. Mention any recent condensate or water leak from the boiler.
Get a Gas Safe registered engineer to look at your Potterton E384
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–£320
Time on site
5 minutes
Electrode £80–£150 fitted. PCB £220–£320. Seal or trap repair £90–£180.
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 detection and spark ignition electrode
7686344£25–£60Authorised Baxi parts distributor
Price checked 28 September 2026
Baxi / Potterton / Main main PCB
£150–£320Authorised Baxi parts distributor
Price checked 28 September 2026
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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.