How to isolate and power off BM2000?

Simple question I know, but I want to repair my leaky shower unit and so I need to switch off the hot and cold water supply to it. Knowing how sensitive the BM 2000, is I would appreciate any advice on how to safely power down and isolate the boiler/BM/water supply system while I fix the shower unit.

IS this a simple matter of powering off the BM, Boiler and switching the mains water off or do I risk somehow burning out a BM pump or upsetting the notoriously sensitive control board (which has already cost me a fortune and an altercation with a so-called engineer). Do I need to do this in any particular order?

Any advice appreciated
Paul

Well I would just turn off the cold supply.
In the cupboard where the unit is located if there is an isolator there.
Or at the mains.
Can see no reason why you would want to power off the unit.
But you can just switch it off if you wish.
Do the job in hand.
Water back on and running as per normal.
Then power the unit back up.
Mike
MGC/H2O
Norfolk

Thanks. That's what I did in the end.