Remeha E.04.10 Fault Code: Causes, Fixes & Repair Costs
What does the Remeha E.04.10 fault code mean?
The E.04.10 code appears on your Remeha boiler when it has made five consecutive attempts to light the burner and failed every time. After these repeated unsuccessful starts, the boiler enters a hard lockout — it shuts itself down completely and will not try again until you manually reset it. This safety mechanism prevents unburnt gas from accumulating. The boiler will display E.04.10 and remain off until the root cause is addressed and the unit is reset by hand.
General guidance only — not a substitute for professional advice, and not certified by a Gas Safe engineer. Always have your specific appliance assessed by a qualified professional. Any gas work must be carried out by a Gas Safe registered engineer. If you smell gas or suspect carbon monoxide, leave the property and call the National Gas Emergency line on 0800 111 999.
Common causes
- Gas supply interruption or low gas pressure Common
If the gas supply to the boiler is interrupted — whether because the meter valve is closed, a prepayment meter has run out, or there is a temporary supply issue in your area — the boiler will find nothing to ignite during each attempt. Low gas pressure at the appliance produces a similar result, as the gas valve cannot deliver enough fuel for stable combustion.
- Faulty or dirty ignition electrode Common
The ignition electrode generates the spark that lights the burner. Over time the electrode tip can become coated in carbon deposits, crack, or shift out of alignment, all of which prevent a reliable spark. A worn or damaged electrode lead produces the same symptom: the gas valve opens but no ignition event occurs, triggering repeated failed starts.
- Fan failure or restricted airflow Common
The combustion fan must reach its target speed before the gas valve is permitted to open. A fan that is slow, seized, or drawing incorrect current will either prevent the ignition sequence from starting or cause a weak, unstable flame that the ionisation probe cannot confirm. Blocked air intake grilles produce a similar restriction.
- Flue obstruction or flue gas recirculation Sometimes
A partially blocked or incorrectly terminated flue can cause combustion gases to be drawn back into the air intake, starving the burner of fresh oxygen. Birds' nests, debris at the terminal, or a flue that is too close to a wall or corner can all cause recirculation. In cold weather a frozen condensate pipe can also create back pressure in the system that disrupts combustion.
- Weak or absent ionisation signal Sometimes
Even when the burner does light briefly, the ionisation probe must detect a stable flame and send a signal back to the PCB. A probe that is dirty, misaligned, or has a broken connection returns no signal, so the PCB treats the attempt as a failure and shuts down. Earthing faults in the wiring harness produce a similar false-negative reading.
- Faulty gas valve or PCB Rare
If the gas valve is mechanically stuck or not receiving the correct control signal, it will not open during the ignition sequence even if all other conditions are met. A PCB fault can similarly prevent the valve or ignition module from being commanded correctly. These are less common but are implicated when electrode, fan, and flue checks all come back clear.
How to fix it
- Check that other gas appliances in your home are working DIY safe
Turn on a gas hob ring or check another gas appliance. If nothing works, the issue is likely with your gas supply rather than the boiler itself. Contact your gas supplier or check your meter — if you have a prepayment meter, ensure it has credit. Do not proceed further until you have confirmed gas is available at the property.
- In cold weather, inspect the condensate pipe for freezing DIY safe
The condensate pipe is the plastic pipe (usually 21.5 mm or 32 mm diameter) that exits through an external wall. In freezing temperatures it can ice up and cause a lockout. If it feels solid, you can carefully thaw it using warm — not boiling — water poured along its length, or wrap it in a hot water bottle. Once thawed, reset the boiler.
- Reset the boiler once DIY safe
Press and hold the reset button (consult your user manual for its location on your specific model) for the duration specified in the manual, typically two to three seconds. Allow the boiler a full minute to attempt a restart. If it fires up and runs normally, monitor it for the next few days. If E.04.10 returns, do not keep resetting — repeated resets without fixing the cause can mask a developing fault and are not a solution.
- Check system pressure is within the normal operating range DIY safe
Look at the pressure gauge on the boiler. For most Remeha models the cold-fill pressure should sit between 1.0 and 1.5 bar. If it reads below 0.5 bar, top it up via the filling loop following the instructions in your user manual. Note that low water pressure will not typically cause E.04.10 specifically, but it is worth ruling out as a contributing factor before calling an engineer.
- Do not attempt to inspect or adjust any internal components Gas Safe engineer
The ignition electrode, ionisation probe, gas valve, fan, flue pipework, and PCB are all beyond the scope of homeowner inspection or repair. Working on gas components without Gas Safe registration is illegal under the Gas Safety (Installation and Use) Regulations 1998 and is extremely dangerous. Leave all internal investigation to a qualified engineer.
- Call a Gas Safe registered engineer to diagnose and repair the fault Gas Safe engineer
If the boiler locks out again after a single reset, or if it never restarts at all, contact a Gas Safe registered engineer. They will carry out a systematic check: verifying gas pressure at the appliance, inspecting the ignition electrode alignment and condition, testing the ionisation signal, checking fan speed and current draw, examining the flue terminal for blockages or recirculation, and testing the gas valve and PCB outputs. They will replace whichever component is found to be at fault.
Parts you may need
- Ignition electrode and lead assembly · from £35
- Ionisation probe · from £30
- Combustion fan · from £120
- Gas valve · from £150
- PCB (main control board) · from £220
The exact spare depends on your boiler's GC number (on the data badge). Check this against the part before buying.
Typical repair cost
Expect to pay roughly £150–£380, depending on the underlying cause.
Frequently asked questions
Can I just keep resetting the boiler to clear E.04.10?
A single reset is reasonable — faults can occasionally occur due to a momentary gas pressure dip or a temporary airflow disturbance. However, if E.04.10 comes back after one reset, repeatedly pressing the reset button will not fix the underlying problem and may mask a worsening fault. You should arrange for a Gas Safe engineer to investigate rather than cycling the reset button.
How much will it cost to fix a Remeha E.04.10 fault?
Most repairs that cause E.04.10 fall in the range of £150 to £380 when you include the engineer's call-out and labour. An ignition electrode replacement tends to sit at the lower end of that range, while a fan or gas valve replacement sits higher. If the PCB turns out to be the cause, costs can push towards £400–£500 or beyond, depending on the model and parts availability. If your Remeha boiler is more than 12–15 years old and needs a PCB or heat exchanger, it is worth getting a new boiler quote alongside the repair quote.
Why does E.04.10 happen more often in cold weather?
Cold snaps increase the risk of the external condensate pipe freezing solid, which creates back pressure in the flue and combustion system, disrupting ignition. Cold weather also tends to increase gas demand across the network, which can briefly reduce supply pressure. If E.04.10 appears during a cold spell and resolves after thawing the condensate pipe, insulating that pipe for future winters is a sensible preventive measure.
Which Remeha boiler models show the E.04.10 code?
E.04.10 is documented across the Remeha Tzerra Ace, Tzerra Ace Matic, and Quinta Ace ranges. The fault code behaviour and the underlying ignition sequence are consistent across these models, so the diagnostic approach an engineer takes will be similar regardless of which variant you own. If you are unsure which model you have, the data plate is usually found on the inside of the front casing.