Mira [I] fault codewhat it means and how to fix it

Code I is Mira’s catch-all for the control software getting into a state it cannot get out of, and the remedy they publish is the shortest in the table: power cycle the unit. That is worth taking at face value rather than treating as a brush-off, because it tells you what kind of fault this is. A software error in this context is not a corrupted program — it is the controller finding itself in a condition its logic does not have a route out of, typically after an interruption at an awkward moment, a supply glitch, or a sensor reading arriving out of sequence.

Removing the supply for long enough that the electronics genuinely lose state, and then restoring it, puts the controller back at a known starting point. Which is why the detail that matters here is how long you leave it off. A second at the pull cord is not a power cycle; the capacitors on the board hold enough charge to keep the controller alive through a brief interruption, and the fault comes straight back because nothing was actually reset. Ten to fifteen seconds off is the practical minimum. The other thing to take from this code is what to do if it recurs. A software error that appears once after a power cut and never returns is exactly what the code is for.

One that comes back every few days is not a software problem in any useful sense — something is putting the controller into that state repeatedly, and the candidates are a marginal supply, a sensor reporting intermittently, or a board that is failing. At that point the power cycle stops being a remedy and becomes a way of postponing a diagnosis.

1. 1

   Switch the shower off at the pull cord or isolator and leave it off for at least fifteen seconds. A brief flick is not long enough to reset the controller.

2. 2

   Switch back on and start the shower. Watch the lights during start-up — if a different indication appears, that is the real fault and this code was masking it.

3. 3

   Run it for five minutes at showering temperature, which is Mira’s own confirmation check, rather than judging it on whether it started.

4. 4

   Keep a note of when it happens if it recurs. A pattern — always after a power cut, always at start-up, always cold — is what turns this into a diagnosable fault.

5. 5

   If it returns within days, stop power cycling it and have it looked at. A recurring software error is a symptom of something else rather than a thing in itself.