help with underfloor heating design

[Zehroni]

I am modernizing my house by installing underfloor heating in whole house, upstairs and downstairs. However, due to the layout of the house I need 3 zones, i.e. 3 manifolds, each 6 circuits. What is the best way to connect these manifolds back to the boiler?

I have

3 manifolds

3 wiring centers

3 zone vales.

I believe the 3 wiring centers will be connected to the same point inside the boiler so that the boiler fires up when any of the wiring center demands heating. However, I am not sure how to connect the manifolds and the zone valves to the boiler as I have only two 22mm pipes connect to the boiler, the feed and the return. I was thinking to run these 2 pipe along the house under the floor board of the firs floor then branch out to the 3 manifolds, but I am not sure if that is possible, any idea. Please

 

[muggles]

You can either split them off at the boiler and run a 22mm flow & return to each manifold location from there, or you could run a 28mm flow & return from the boiler through the house and branch off that in 22mm to run to the manifolds. Either way, you'll need a zone valve for each circuit