Ideal SE status codewhat it means
A service reminder, not a fault. The installer set a timer at the last visit and it has run down. Ideal's advice is to contact the installer, who resets it when the boiler is serviced.
Before you start
What SE means
Ideal's fault codes page lists "Flashing S AND E — Service Interval Timer" and gives one instruction: please contact the installer. That is the whole of what Ideal publish for the householder about SE, and it is enough, because the code is not the boiler reporting anything wrong with itself.
Logic boards carry a service timer that an installer can switch on in the installer menu — the ESP1 installation manual lists SE among the menu steps, after the venting function and pump speed settings, with the note that the service timer function is covered in separate instructions — and when the set interval has passed the display flashes the code to say a service is due. The boiler goes on working. Landlords' boilers and boilers on service plans are the ones most often set up this way, since the timer is a nudge to book the annual visit that keeps a warranty valid and a gas safety record current.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| The service interval set by the installer has elapsed | This is the only cause. The timer was enabled at installation or at the last service, and the boiler has now run for the set period. | Common |
| Timer left enabled by a previous owner's installer | In a house you have just moved into, SE can be the first you hear that the boiler was ever on a service plan. The reminder is still worth acting on. | Occasional |
What to try yourself
Carry on using the boiler. SE does not stop it and there is nothing to reset from the front panel; the timer is cleared from the installer menu.
Book an annual service with a Gas Safe registered engineer — Ideal say the installer, but any registered engineer can service the boiler and clear the timer, and if you rent, it is your landlord's job to arrange.
Get a Gas Safe registered engineer to look at your Ideal SE
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
£80–£140
Time on site
5 minutes
The cost of the annual service it is reminding you about: typically £80–£140 for a combi.
Typical UK prices including parts and labour, updated September 2026. Your quote may differ.
Own this appliance and had this code? . Nothing is published until a person has read it.
Related Ideal fault codes
- F9Get it checkedThe control board has not been told what boiler it is in, or has failed. L9 is the same fault locked out. The 2011 Logic Combi row also covers a gas valve short circuit.Related: electronics and power
- dUUsually simple to fixNot a fault. The diverter valve has been parked in its mid-position for servicing and the boiler is waiting to be told the service is over. Ideal publish the way out.Related: electronics and power
- Blank displayGet it checkedNothing on the screen at all. Ideal's user guides send you to the boiler's switch and the consumer unit first; the installer charts then work from the terminal block to the board.Related: electronics and power
- F7Get it checkedThe mains voltage reaching the boiler has dropped below what the board will run on. Ideal's advice is an electrician or your electricity supplier, not a heating engineer.Related: electronics and power
- C0Get it checkedThe board cannot activate the Boiler Chip Card that tells it what model it is fitted to. Ideal's engineer check is whether the small plastic card is in its slot at all.Related: electronics and power
- L9Get it checkedOn a Logic, L9 is the locked-out form of the unconfigured-board fault F9. On an Isar HE it is something else entirely: a heat exchanger overheat read by the dry-fire thermistor.Related: electronics and power
Own an Ideal boiler? Save it and its codes come first next time.
Related guides
Common questions about Ideal SE
Can I turn the reminder off myself?
Not from the user controls. The service timer lives in the installer menu, and Ideal refer even installers to separate instructions for it. Treat it as a reminder to book the visit rather than a setting to defeat.
Is the warranty affected if I ignore it?
The code itself does nothing to the warranty. Missing the annual service it is reminding you about can, because Ideal's warranties require the boiler to be serviced every year by a Gas Safe engineer and the Benchmark record filled in.
Which boilers show SE?
Logic boards with the timer enabled — Ideal's FAQ lists it alongside the Logic codes, and the ESP1 installation manual carries it in the installer menu. A Logic shows it only if the timer has been enabled from that menu, so a boiler that has never shown SE has it switched off.
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 support portal
- 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.