Quite a bit involved in fitting a fully pumped system to your existing set up,personally I wouldn't bother if I were you however you need to cap one of the flows and link the two returns but you will require a spreader to do this which goes inside the boiler on the bottom return.
The other flow goes to your pump (expansion pipe before BTW)and from there you pipe to your mid position/divertor valve however I would go for an s plan with two zone valves and you'll need an auto by-pass valve fitted between the two zone valves.
The return from the cylinder goes right back to the first tee at the boiler return and your rad return goes to the other side of the tee.
Check the MIs tells you all you need to know re pipework.
Best of luck.
The other flow goes to your pump (expansion pipe before BTW)and from there you pipe to your mid position/divertor valve however I would go for an s plan with two zone valves and you'll need an auto by-pass valve fitted between the two zone valves.
The return from the cylinder goes right back to the first tee at the boiler return and your rad return goes to the other side of the tee.
Check the MIs tells you all you need to know re pipework.
Best of luck.
