Mira L fault codewhat it means and how to fix it
Status light off entirely, with Start/Stop off. Mira call this an electrical fault and the action is to check power to the shower.
Take care
What L means
Code L is the odd one in this table because it is the absence of an indication rather than an indication. Everything else Mira publish is a colour and a rhythm; L is both lights off, and their cause and action are as short as anything in the document — electrical fault, check power to the shower. Read literally that is exactly right, and it tells you where to look. A shower with no lights at all has, from its own point of view, no supply.
The electronics that would run the Status light are the same electronics that would report a fault, so if nothing is lit then nothing has power, and the question moves off the appliance and onto the four things between it and the consumer unit: the breaker, the cable, the isolating switch, and the connection at each end.
In practice the isolating switch is the single most likely answer on an installation of any age. A ceiling pull cord is a mechanical switch operated with a wet hand several times a day, and its contacts wear out; a cord that no longer clicks decisively, or whose indicator has stopped moving, is a switch at the end of its life. The second most likely is the breaker, and if that has tripped rather than simply being off then the reason it tripped matters more than the reset. What L does not usually mean is that the shower has failed internally. That is possible, and it is where the diagnosis ends up if the supply checks out, but Mira’s own action points outward for a reason.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Isolating switch or pull cord failed | The only mechanical part in the supply chain and the one that wears. Very common on installations more than about ten years old. | Common |
| Breaker tripped or switched off | Check whether it tripped or was simply off. A breaker that trips again under load is a different and more serious problem. | Common |
| Loose connection at the switch or the shower | A high-current terminal that has worked loose. Often accompanied by discoloured plastic, which changes the answer entirely. | Occasional |
| Internal supply board failure | Power arriving at the shower but nothing lighting. Only reached once the supply side has been ruled out properly. | Occasional |
What to try yourself
Check the shower breaker at the consumer unit — the largest one in the board, usually 40 or 45 amp. Note whether it tripped or was off.
If it has tripped and trips again when the shower runs, stop resetting it. That is an electrical fault in the circuit, not a shower that needs restarting.Pull the cord and listen for a definite mechanical click. A soft, sticky or silent cord is a failing switch and is the commonest cause of this code.
Look at the pull cord ceiling rose and the shower for browning, staining or a hot-plastic smell. If you find any, leave the circuit off and treat it as an overheating connection.
If the breaker is healthy and the cord clicks but the shower stays dark, the fault is between the switch and the appliance and needs testing rather than guessing.
Get a qualified electrician to look at your Mira L
We do not pass enquiries to a repair firm, so there is no form here. When you book a qualified electrician, tell them the make, the model and the exact code or message on the display, and ask whether they carry parts for this make — that is what turns one visit into a repair rather than a quote.
What it costs to fix
Typical repair cost
£0–£140
Time on site
20 minutes
Nothing if the switch was off. A replacement pull-cord switch fitted is the usual outcome. A fault inside the unit puts you into board-replacement territory.
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 Mira fault codes
- AGet it checkedFlashing red on the Status light. Mira group three water-supply problems under this one code: no supply, low pressure, or a blockage somewhere in the outlet.Related: same brand
- DGet it checkedFlashing red and yellow. The outlet thermistor has seen a temperature above what Mira allow, and the shower has stopped rather than deliver it.Related: same brand
- MUsually simple to fixFlashing white. Not a breakdown — the shower was switched off at the cord before it finished its shutdown, and it will not restart properly until it settles.Related: same brand
- FGet it checkedFlashing red and blue with Start/Stop flashing. The cold water arriving at the shower is already hotter than Mira allow it to be.Related: same brand
- IGet it checkedFlashing red and white with Start/Stop flashing. Mira call it a software error, and their published remedy is simply to power cycle the unit.Related: same brand
- CGet it checkedFlashing red and yellow with Start/Stop off. A thermistor fault: the shower has lost the temperature sensing it relies on to stay safe.Related: same brand
Own a Mira electric shower? Save it and its codes come first next time.
Related guides
Common questions about Mira L
Does code L mean the shower is broken?
Usually not. Mira’s own action is to check power to the shower, which points at the supply rather than the appliance, and in practice the isolating switch or the breaker accounts for most of these.
How is this different from the shower simply being switched off?
From outside, it is not, which is why the first checks are the free ones. The code exists because the appliance cannot distinguish between having been switched off and having lost its supply.
Is replacing a pull cord switch a big job?
No. The part is inexpensive and it is a short visit for an electrician. It is one of the cheaper outcomes here, which is why it is worth ruling in before assuming the shower has failed.
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.