help understanding gravity system

[antych]

I'm renovating my bathroom and want a better showering solution (there was an electric shower installed by previous owner, fed from the mains).

From what I've read I have a pretty standard gravity system, with a cold water tank in the loft and a heater in a cupboard. It looks like I will have to install a pump to have a proper shower, but there's something I don't understand and hopefully someone can explain. Cold water has such a poor pressure that if I lift the shower head above my head it stops running. Hot water on the other hand, seems to flow just fine and it seem to have higher pressure in taps as well.

If I understood this correctly, water heater is fed from the gravity tank just like cold water taps. Shouldn't cold and hot water have the same pressure then?

Even when I raise the shower head, it's still about a meter below the water tank. Shouldn't cold water still run? (we already checked if the pipes are blocked)

Does it have anything to do, with cold water going into toilet, or hot water being mixed with cold mains water in the kitchen tap?

Thanks
Carl

 

[JackGlos]

Due to the cold water running low pressure (Coming from the Storage tank in the loft) and the hot is normal (coming from the Cylinder), all i can think of is that are you sure its a meter below the tank when using the shower head? if it is i would recommend on trying a low pressure shower head to see if that works. If not install a booster pump/ power shower.

 

[Dan Masey]

Salamander shower pump all the way. Thermostatic showers fed from cylinders are dreadful. Fit it in the airing cupboard next to the hot water cylinder.

 

[PlumbBobBob]

i agree in putting a pump in, but i would go for a stuart turner one personally.

 

[stevetheplumber]

stuart turner every time for me as well

 

[Destroyer2813]

Stuart Turner for me as well better quality

 

[antych]

Thanks for the advice it may come useful, but I was really asking about pressure difference. It turned out someone had to step on one of the pipes in the loft. It bent upwards and was probably holding air, reducing cold water pressure. Now pressures is balanced and shower works fairly well, even without a pump.

Carl