Main boiler fault code E128 means the appliance has detected flame failure during normal operation. Baxi’s current error-code reference describes E128 for the appliance group containing Main Eco Compact Combi and System boilers as a safety error for frequent loss of flame.
The boiler may light and then lose its flame, or it may record repeated flame-loss events before locking out. The code does not identify one failed component and should not be used as a reason to adjust the gas supply, burner or ignition parts.
What does Main E128 mean?
A gas boiler must prove that a stable flame is present whenever the burner is operating. If the flame signal is lost, the controls stop the gas supply as a safety response. The Main Eco Compact service manual describes E128 as flame failure during normal operation, while Baxi’s current public table adds that it is a safety error for frequent loss of flame.
That wording matters: the boiler is responding to a flame that has been lost after operation began. This is different from assuming that the boiler never attempted to light.
Which Main boilers use E128?
Baxi’s current grouped fault-code table includes Main Eco Compact Combi and Main Eco Compact System models. Main has made other boilers with different controls and code sets, so check the full model name before applying this explanation.
The model name may be on the front casing, user paperwork or Benchmark record. Photograph the entire display, including any flame symbol or additional number, so the correct manual can be checked.
How is E128 different from E133?
E128 relates to frequent flame loss or flame failure during normal operation on the applicable Main Eco Compact models. E133 is described separately and can concern interruption of the gas supply, ignition failure or failure to detect a flame during the starting process.
The two codes can feel similar because both can leave the boiler without a working burner, but they describe different points in the operating sequence. If your display actually shows E133, use our Main E133 fault-code guide rather than treating it as E128.
What symptoms may come with E128?
- The boiler starts and then stops.
- Heating or hot water works briefly before the lockout.
- The flame symbol disappears while there is still demand.
- The code returns after a reset.
- Both heating and hot water become unavailable.
The timing is useful. Note whether E128 appears during heating, while a hot tap is running or in both situations. Do not try to reproduce the fault repeatedly.
Can I reset Main E128?
The Main Eco Compact service literature includes E128 among codes for which the reset control may relight the boiler. If the user guide for your exact model permits it, one reset can be tried using the normal front control.
If it has no effect, the code returns or the boiler repeatedly lights and stops, leave it off and arrange a repair. Repeated resets do not correct flame loss and can make the sequence harder to assess.
Safe checks you can make
- Confirm the exact boiler model and photograph the complete display.
- Check whether the home’s normal gas supply appears to be available without touching the boiler internals.
- If you use a prepayment meter, confirm it has credit and is not displaying a supply message.
- Note whether the fault affects heating, hot water or both.
- Record whether it began after a power cut, gas interruption or recent work.
- Listen from outside the casing and note whether the boiler starts before stopping.
Do not remove the casing, inspect the burner, clean electrodes, adjust the gas valve or interfere with the flue. Never test for gas with a flame.
What can cause flame loss?
Several different conditions can lead to an unstable or lost flame signal. The engineer may need to consider the gas supply, ignition and flame-sensing system, combustion, flue arrangement, electrical connections and boiler controls. The relevant checks depend on the appliance and the sequence stored by its controls.
E128 therefore should not be translated into a shopping list for a gas valve, electrode or circuit board. Replacing a part without testing can miss the real fault and does not confirm safe combustion.
Is Main E128 dangerous?
The lockout is a safety response and should not be bypassed. A boiler displaying E128 should be repaired before normal use resumes, particularly if the code returns after the permitted reset.
If you smell gas, do not operate electrical switches, smoke or use a naked flame. Open doors and windows if safe, move away from the property and call the National Gas Emergency Service on 0800 111 999. If a carbon-monoxide alarm sounds or anyone has symptoms such as headache, dizziness, nausea or breathlessness, move to fresh air, call the emergency number and seek medical help.
What will the engineer check?
The engineer will confirm the exact model and fault history, establish when the flame is being lost and carry out the appropriate gas, combustion, ignition, electrical and flue checks. Any work involving the gas train or combustion circuit must be completed by a suitably qualified Gas Safe registered engineer.
The correct repair follows those results. Once repaired, the appliance can be checked for reliable operation and safe combustion rather than simply being reset and left to run.
What information should I send?
Include a clear photo of E128, the full model name and a short description of what happened immediately before the code appeared. Say whether the boiler had been running for seconds or several minutes, whether heating or hot water was requested and whether the fault has happened more than once.
Mention any recent loss of gas supply, power interruption or work at the property. Do not attempt to open the appliance to provide more detail.
Get your Main boiler working reliably again.
Choose a fixed-price boiler repair so the E128 flame-loss fault can be checked safely and the right repair completed.
Main E128 FAQs
Does E128 mean there is no gas?
Not necessarily. It records flame loss on the applicable model, but the reason requires proper checks.
Can I reset E128?
One reset may be tried only if the exact user guide permits it. Arrange repair if the code remains or returns.
Is E128 the same as E133?
No. They relate to different flame or ignition conditions in the manufacturer’s fault information.
Can I clean the electrode myself?
No. That requires opening the gas appliance and must not be attempted by a homeowner.
Can I keep using the boiler if it restarts?
A returning E128 fault still needs repair. A temporary restart does not prove that the flame-loss problem is resolved.