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

The cover PCB is the electronics in the front of the shower, the part you actually interact with. It carries the Start/Stop button, the status lights and the temperature control input, and it talks to the boards behind it. Code H means that board has failed, and Mira publish exactly one action for it: contact customer services. What makes this code awkward, and worth its own page rather than being folded in with the other board faults, is that the thing which has failed is also the thing the diagnostic depends on.

Mira’s entire fault-reporting scheme on this appliance is two lights, and those lights are driven by the cover PCB. So a partial failure of that board can produce indications that are misleading — lights that do not match the underlying condition, a button that reports itself pressed when it is not, an indication that changes when nothing else has. This is the one code in the table where the reported fault and the reporting mechanism are the same component.

Mira appear to be alert to that: a cover PCB failure appears three separate times in their table, reachable from three different initial states, which is unusual and suggests they expect it to present inconsistently. For an owner the practical consequence is simple. If the lights are behaving oddly rather than showing a clean pattern, do not spend a long time trying to decode them — record what you see, note that it is inconsistent, and pass that on. Inconsistency is itself the diagnostic here.