myenergi zappi Overheating
Two stages, both published: wavy lines over the zappi icon mean thermal limiting with reduced output, and the Overheating! message means the output is off. Ventilation is the remedy and charging resumes on its own.
Take care
What this means
The zappi reports heat in two stages, and myenergi publish both. The first is a symbol: wavy lines above the zappi icon on the main display, which the manual explains as the unit thermally limiting, with the output power temporarily reduced. The second is a message in the fault table, Overheating!, carrying no code number, which myenergi describe as the zappi unit being too hot with the output switched off. Their published remedy for the message is short and specific: make sure the zappi is properly ventilated, for example that it has not been covered, and the charge will resume once the unit has cooled down again. The installation manual joins the two: if the zappi gets too warm it first reduces the charge rate and shows the icon, and if its internal temperature keeps rising it trips the output and shows Overheating!, resuming normal operation once the temperature drops.
The thing to notice is the first stage, because it means the unit does not necessarily stop. It may keep charging at a reduced rate for some time before anything is written on the screen, which produces the more confusing symptom of a charger that works but is inexplicably slow. If you have been chasing a charge rate problem, the wavy lines are worth ruling out before the CT clamp and the car. The causes are mostly environmental and mostly avoidable. A unit in direct afternoon sun on a south-facing wall will run considerably hotter than the same unit in shade. A cover, a tarpaulin or something leaning against it — a bike, a wheelie bin, a bag of compost — restricts the airflow it is designed around.
A cable coiled tightly against the unit does the same. And a unit installed in a garage or a covered porch with poor air movement can accumulate heat over a long session even without direct sun. There is also a heat source people do not think of: charging at full rate for hours generates real heat in the electronics, so the units that meet this most often are the ones doing the most work, on the warmest nights, in the least ventilated positions. If the symbol or the message appears in cool weather on a well-ventilated unit that is not covered, that is different. At that point it is reporting something about itself rather than about its surroundings, and it is worth contacting myenergi rather than working around it.
What causes it
| Cause | What is actually happening | How likely |
|---|---|---|
| Something covering or leaning against the unit | myenergi name this explicitly in their remedy. A cover, a bag, a bin or a bike against the enclosure restricts the airflow the unit needs. | Common |
| Direct sun on the enclosure | A charger on a south or west facing wall gets a great deal of solar gain in the afternoon, on top of the heat it generates itself. | Common |
| A long session at full rate | The electronics generate heat in proportion to the work. A full-rate charge over several hours on a warm evening is the combination that reaches the limit. | Occasional |
| Poor air movement where it is installed | A closed garage, a tight recess or a covered porch can hold heat around the unit even without direct sun. | Occasional |
| A fault in the unit itself | The case to consider if the symbol appears in cool weather with nothing covering it and good ventilation. That is worth a call rather than a workaround. | Rare |
What to try yourself
Look at the unit and move anything touching it or leaning against it. myenergi’s own remedy names being covered as the thing to check.
Uncoil the cable rather than leaving it wrapped tightly around or against the enclosure, so air can move over the case.
Wait. myenergi publish that the charge will resume once the unit has cooled down, so there is nothing to reset.
If the symbol appears on hot afternoons, shift charging later into the evening. The unit is cooler and so is the air it is shedding heat into.
If you have been chasing a slow charge, check for this symbol. Thermal limiting reduces the rate rather than stopping the session, which is easy to mistake for a supply or clamp problem.
If it happens in cool weather with nothing covering the unit, contact myenergi rather than working round it.
Get a registered electrician to look at your myenergi zappi ev charger
We do not pass enquiries to a repair firm, so there is no form here. When you book a registered 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
Time on site
20 minutes
Nothing in the ordinary case — it is protection working and it clears itself. A service call only if it happens in cool weather on a well-ventilated unit.
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 myenergi zappi fault codes
- OverloadGet it checkedCode 30: the car is drawing more current than the zappi offered, so the output has been switched off. Reset, and if it repeats the question is the car, not the charger.Related: power and throttling
- PEN FaultStop — call an engineerCode 29. The protection against loss of the supply earth-neutral conductor has operated, and myenergi tell you to remove the fault before resetting.Related: same brand
- PE FaultStop — call an engineerCode 25. myenergi say the earth is either disconnected or its impedance is too high — a problem in the installation rather than in the charger.Related: same brand
- SelfTest FailedGet it checkedCode 27, searched as A27. The built-in protection devices could not be tested, or failed the test, before a charge. myenergi’s action is a reset; they do not say it cannot be repaired.Related: same brand
- Charge BlockedUsually simple to fixNot a fault. The car keeps asking to charge after it already reported complete, and the zappi has stopped answering.Related: same brand
- Lock FailureGet it checkedCode 23, and the fix is counter-intuitive: push the plug further in to release it. Untethered zappis only.Related: same brand
Own a myenergi zappi ev charger? Save it and its codes come first next time.
Related guides
Common questions
Why is there no code number for this?
Because myenergi print Overheating! in the fault table without a number, and the earlier thermal-limiting stage is a symbol rather than a message — wavy lines over the zappi icon. Both sit outside the numbered set along with the pilot, cable and charge blocked messages, which is why they are hard to look up and why people describe them rather than search for them.
Do I need to reset anything?
No. myenergi publish that the charge will resume once the unit has cooled down again. The only action they give is making sure it is properly ventilated and not covered.
Could this be why my charging is slow rather than stopped?
Yes, and it is worth checking before you look at anything else. myenergi publish the wavy lines above the zappi icon as the unit thermally limiting with the output power temporarily reduced, so on a warm day the unit may keep charging at a reduced rate for a long time before it ever shows Overheating!, which presents as an unexplained slow charge.
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.