[Sobertone]

I want to install a power shower in a bathroom which is fed by a Manco Immersion tank/cylinder. The Manco cylinder has a smallish cold feed section of the tank incorporated at the top with a larger cylinder below where the water is heated by two immersion heaters (one is Economy 7) I wanted to install a Triton or Bristan type power shower where the unit on the wall incorporates a small pump which allows the flow (10/15 Litres per min) to be controlled along with the temperature. The manufacturers say these units are suitable only for gravity fed systems but will work with pressure as low as 0.1 Bar. The shower unit will be about the same height as the top of the Manco cylinder hot output.
Currently the bath taps are connected with 15mm pipe and the flow from these is excellent.
I am concerned that the shower unit will not be suitable as the cold (mains) pressure is likely to be considerably more than the hot given the lack of height differential between the shower head and hot water supply.
The property is an all electric apartment with no possibility of a feed tank in the loft (there is no loft).
I will be very grateful for any help or advice anyone can offer - Many thanks