Hot and cold water feeds go directly from the storage tanks into the Aquavalve mixer valve located in the shower enclosure Mixed hot and cold water then flow up through a 22mm feed into the pump in the attic (probably 2m+ height difference between mixer valve and pump) The pump then pumps the pre mixed water through a 22mm outlet back to the shower head outlet. Hot water tank is located in the airing cupboard next to the en-suite Bottom of the 40 gallon cold water tank is probably 1m+ above the shower head and 30-50cm above the pump Bottom of 40 gallon hot water storage tank is probably 1-1.5m below the shower head Without the pump active, there is very low water flow from the shower head. The pump sits on the attic floor beside the cold water storage tank. The present set up is plumbed into the ensuite bath on the second floor.