Can you tell me how this is done?

I have a gravity hot water system and a pumped central heating system fed from the same boiler (very old).

This means i have no control over the water independantly of the heating.

The boiler has a feed to the indirect hot water cylinder and a return as does the central heating.

How can i convert this system to fully pumped?

Ive read that i could convert it to a Y plan using a 3 port valve.

Is this correct? and advice???

 

you will need to change the cold feed and vent pipes that should be on the flow and returns on your cylinder, if you dont then it will pump over and keep filling your rads with air and will also cause the system to sludge up, To do it right a new cold feed and vent should be run back to the boiler and the old ones, cold feed bottom pipe capped and vent pipe top one should have an auto vent fitted, realy if i was you i would get a plumber to look mate as its needs doing right as it needs doing to part L and P

 

Cheers Dunc,

So as it is at the moment, i have 2x flows and 2x returns.

1x pair supply/return the radiators via the pump, the other pair supply/return via gravity hot water cylinder.

So my understanding is that i would need a flow connected to the vent with a cold feed alongside, running to the pump, from the pump to the 3 port valve, 1 side of valve to hot water cylinder other side to radiatior circuit.

sound right?