Mira Advance Electric shower Diagnostic

I have a Mira Advance Electric shower, approx 2 yrs old, with a totally unknown problem. The water heater 'tank' does not appear to have any residue, and still has some water in it, so I am assuming that it is not a water problem.
As it is 9.8kW, I cannot plug it into the 13a ring main and trailing a lead from the consumer unit to somewhere that I can connect a water feed, will be a problem.
Does anyone have a diagnostic procedure which I can use to establish what or whether there is a problem with it. I could connect a low voltage supply to test the circuit boards, or disconnect the heating elements and connect to the 240v

so what is the shower doing ? then we can tell you what to check.

Phone Mira,

01242262888

Their tech line is as good as it gets.

BTW,the shower may still be under gaurantee some Mira showers come with three and five year warranties The Advance is pretty much at the top of the range.

I was a little unclear in my explanation of my problem. The shower is not connected anywhere. I got screwed on Ebay and I believe that the shower has aproblem. I am looking for a way to prove that it is ok or to identify what the problem is before I fit it permanently. Therefore I need to find a way of connecting to a power source which will supply enough current, safely. I can connect a water supply with a hose, but I need to be somewhere that can handle the discharge flow. Any ideas which will help diagnosis will be appreciated.

the water supply is not the problem as you say you can use a hose but its supplying the electric feed.