Main Eco Compact E128 fault code: frequent flame-loss safety error
The Main Eco Compact E128 fault code means “Safety error for frequent loss of flame” in Baxi’s current error-code table. The table places E128 in the model group that includes Main Eco Compact Combi and Main Eco Compact System boilers.
The Main Eco Compact manuals use the shorter description “Flame failure”, and the System installation manual says E128 is displayed when flame failure occurs during normal operation. Together, those sources describe a safety lockout caused by repeated or operating flame loss. The code does not identify why the flame was lost.
What does “loss of flame” mean?
A gas boiler must confirm a stable flame while the burner is meant to operate. If the flame signal is lost, the controls can stop the gas supply and end the firing cycle. E128 is the safety message associated with frequent flame loss rather than a request for the homeowner to inspect the burner.
The display cannot tell you whether the underlying issue is related to the gas supply, ignition, flame monitoring, combustion, wiring, the flue or another control condition. Those possibilities require competent testing. It would be unsafe to order a gas valve, electrode or any other part based on E128 alone.
What you may notice with E128
Depending on when the flame is lost, you may find:
- the boiler starts and then stops;
- heating begins but the radiators cool again;
- hot water on a combi turns cold during use;
- the boiler makes several start attempts;
- E128 returns after a reset;
- another code appears before or after E128; or
- the problem is intermittent rather than constant.
These symptoms help show the pattern but do not prove the cause. Note whether the fault occurs during heating, hot-water use or both, and how long the boiler runs before it stops.
If the boiler repeatedly shuts down, [why a boiler keeps turning itself off](/boiler-help-boiler-turns-off/) explains the difference between normal cycling and a repeating fault. If it will not fire, [safe checks before calling an engineer](/boiler-help-boiler-not-firing-up/) may help you record the wider household symptoms.
Is E128 the same as E133?
No. The current Baxi table lists E128 as frequent loss of flame. It lists E133 separately as a gas-supply fault. The Main manuals also distinguish flame failure during normal operation from an interruption of gas supply or ignition failure.
A homeowner may experience similar results—no heat or no hot water—but the codes represent different points in the boiler’s operating sequence. Record the exact code rather than describing all flame-related lockouts as “ignition faults”.
E129 is also different. Baxi uses E129 for frequent flame loss with maximum correction during ignition during the Calibration Function. That specific calibration context is not part of E128’s public wording.
Does E128 apply to every Main boiler?
No. Fault codes depend on the range. Baxi’s current table includes Main Eco Compact Combi and Main Eco Compact System in the applicable group, and the Main Eco Compact manuals list E128 as flame failure.
Confirm the full model name on the appliance or its documents. Do not assume E128 means the same thing on an unrelated Main model, and do not shorten or change the displayed number.
Safe observations to record
Keep the boiler closed. Useful information includes:
- The exact model and code. Photograph the display if convenient.
- The demand at the time. Was the boiler serving heating, a hot tap or both?
- How long it ran. Note whether it stopped immediately or after several minutes.
- Whether the fault is repeatable. Record the time and circumstances, not repeated reset attempts.
- Other display messages. Keep the order in which codes appear.
- Recent interruptions. Mention any known power cut, meter issue or interruption reported by your gas supplier.
- Other household effects. Record whether other gas appliances have also stopped, without repeatedly operating them as a test.
- Unusual signs. Note any smell, visible soot, smoke, scorching or carbon-monoxide alarm.
These observations give an engineer a clearer fault history without exposing anyone to combustion or gas components.
What not to do
Do not:
- remove the boiler casing;
- inspect or clean the burner;
- touch the ignition or sensing electrodes;
- alter the gas valve or gas-pressure settings;
- inspect or dismantle the flue;
- test wiring, connectors or circuit boards;
- enter installer settings;
- hold the reset control repeatedly; or
- try to keep the boiler running through repeated lockouts.
The lockout is a safety response. Bypassing it or repeatedly restarting the appliance does not make the flame stable.
Can I reset E128?
The Main Eco Compact System installation manual includes E128 among the codes that may be reset. The user guide explains that a fault showing the R symbol can be reset by the user, while a spanner symbol requires support.
If the exact display shows R, the exact model guide permits it and there are no gas, burning or carbon-monoxide warning signs, try one reset. If E128 returns, stop resetting and arrange repair. The manufacturer manual says a code that appears regularly needs further investigation.
A reset clears a lockout; it does not repair the condition that caused flame loss.
When to book a repair
Arrange a repair when:
- E128 remains or returns;
- the boiler repeatedly starts and stops;
- heating or hot water is unreliable;
- a second fault code appears;
- the problem follows work on the boiler or gas supply; or
- you are uncertain whether the appliance is safe to use.
An engineer can assess the flame-safety sequence with the correct equipment. That is the safe way to determine the repair required without guessing from a single code.
Gas and carbon-monoxide safety
If you smell gas, do not use electrical switches or naked flames. Leave the property and call the National Gas Emergency Service on 0800 111 999 from a safe place.
If a carbon-monoxide alarm sounds, or anyone has headache, dizziness, nausea, weakness or confusion, move into fresh air, seek medical help and follow emergency guidance. Do not use the boiler again until it has been checked by a suitably qualified Gas Safe registered engineer.
Soot, scorching, smoke or a persistent burning smell also need urgent attention. Do not remove the casing to investigate.
Ensure your boiler is running safely
Quick Answers
What does Main Eco Compact E128 mean?
Baxi’s current table calls it a safety error for frequent loss of flame.
Does E128 prove the gas valve is faulty?
No. The code records flame loss but does not identify a failed component.
Is E128 the same as E133?
No. Baxi lists E133 separately as a gas-supply fault.
Can I keep resetting E128?
No. If the exact guide and R symbol permit it, try once. A returning code needs investigation.
Can I inspect the burner or electrode?
No. Keep the casing closed and leave gas, ignition, flame-sensing and combustion work to a Gas Safe registered engineer.
Is E128 dangerous?
It is a safety lockout and should not be ignored. Gas smells, a carbon-monoxide alarm, soot, smoke or scorching require urgent safety action.
Do I need an engineer?
Yes if E128 remains, returns, interrupts heating or hot water, or appears with another code.