Converting My House To Manifolds. Feedback Appreciated

[jakehowl]

I'm sold on the idea of sanitary manifolds. I'm an avid and capable DIYer but finding the information out there on domestic manifolds systems lacking to say the least.

Here's a diagram for my proposed approach to converting my house over from your usual 15mm pipe with T junctions everywhere over to a manifold system.

I'd appreciate general feedback. Especially if I've got it completely wrong, but also on the 3 following points:

1. Should the boiler be supplied from one of the manifold outlets?
2. Is it worth using the 1" cold manifold in the cellar - or would 3/4" suffice?
3. Is it worth using 22mm pipe to run the cold upstairs?
   
   

 

[ShaunCorbs]

Are you planning on a secondary return

Only change I would do is 20mm to the bath ideally 25mm depending on your boiler flow rates eg power

 

[jakehowl]

Are you planning on a secondary return

Only change I would do is 20mm to the bath ideally 25mm depending on your boiler flow rates eg power

Not sure what a secondary return is?

The hot coming out of the boiler is only 15mm. Is there any value having larger bore pipes elsewhere? Does the 15mm coming out the boiler bottle-neck the flow?

 

[ShaunCorbs]

Depends on the kw of the boiler not typically but 20mm mlcp is 15mm internally

 

[jakehowl]

Depends on the kw of the boiler not typically but 20mm mlcp is 15mm internally

I should have mentioned it's a 30kw combi boiler, so there are no tanks involved and no option for 2ndary returns?

Interesting about the 20mm MLCP inner bore. So you're suggesting that as 16mm MLCP will become an even bigger bottleneck than the 15mm copper already is?
My only issue is the cost of both the 20mm MLCP and the additional press head I will need for it (I currenlty only have the press for 16mm fittings).