Boiler and water pressure issues

[Waj]

Hi there,
I have an old boiler/water tank installation in my flat. I'd like to change it with a new system in order to save space and get ride of some water tanks. I have a 2 cold water tank one supplying cold water and flush in the bathroom and a cold water tanks supplying a hot water cylinder in the bedroom. My flat being on the top floor of a converted victorian house, the water flow and pressure is subject to the 2 flats below using the water comin from the mains. The water flow rate varies between 6.5 litres/minute and 13.5l/min best case, and water pressure is around 1.8bar.
I am worried that putting a combi boiler into this system would give me poor pressure in the shower in the morning so I m trying to look at alternatives. A plumber suggested to keep one of the water tank in the loft and install a pump which would feed water into a combi boiler. But this solution is quite onerous and some plumbers adivised me not to install pumps with combi boilers (not sure why). Is that right ?
Any ideas on other alternatives ?

Thanks

 

[Plumbstar Tom]

you cant install a pump on to the combi thats mental

you will be best of with a decent electric shower probably or a twin pump off the current supplies

 

[ferret]

You can use a system boiler and a megaflo or similar with 22mm mains feed , the pressure will hold enough to shower and general washing etc but may fizzle slightly when running a bath , that way you,ll lose the tanks and have a modern system.

 

[mrlennie]

The reason not to install pump from the tank onto a combi is that you would be firing water out faster than filling up. Within minutes your tank would be empty. Also combis aren't meant to deal with that kind of pressure.

 

[Danny100uk]

You can use special pumps to pump quite big stores of water through certain multipoint water heaters which we have used to run 12 showers in a changing room. It takes some adjusting to make sure you dont end up making it suck to much but once set up all 12 showers worked at very good pressure! If you want more infomation i can get it for you?