Mira Essentials Thermostatic Power Shower - post 1999

A: Checking the filters would be a good place to start, also check all the gate valves are fully open.

A: 1.  Water and electricity are not a good mix so must recommend you get this fixed.
2.  The pump/motor assembly cnnot be repaired so must be replaced.
3.  As long as the valve is turned to off it should not be necessary to isolate wateer supplies but to be safe would recommend you do so.
Replacement pump/motor assembly can be ordered online by clicking on this link.

http://www.showerdoc.com/shower-spares/mira/MIRA-419-50-Mira-Pump-Assy-419-50

A: The difference is in the control knobs , the 2 links below will show the difference.
You definately need a new motor/pump assy and the appropriate one can be ordered online via the appropriate link.

http://www.showerdoc.com/shower-spares/mira/MIRA-PARENT-151-Mira-Essentials-Manual-Power-Shower---post-1999

http://www.showerdoc.com/shower-spares/mira/MIRA-PARENT-149-Mira-Essentials-Thermostatic-Power-Shower---post-1999

A: 

It will be leaking from somewhere inside, you will have to switch off the power remove the cover and have a look inside to see if you can spot the leak.