10mm manifold on micro bore system

Postby kingsdown » Thu Jul 21, 2011 3:54 pm

I have a 10mm micro bore central heating system with manifold. I have added 2 extra radiators by teeing into an existing radiator as manifold is full. New radiators are luke warm and existing teed radiator is luke warm.
My next thought is to install another manifold piggy back style(No room to put bigger manifold in). Then pipe from the new manifold to the 2 new radiators.
Having spoken to 3 plumbing suppliers, the best I got from one was I needed a Wednesbury manifold which is not made any more.
So two questions:-
1. Am I doing the right thing?
2. Where can I buy a manfold to bo this job?
PS Existing manifold is 28mm in/out with 10mm out/return pipes from/to radiastors.
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Simply Build It

Postby Perry525 » Tue Aug 02, 2011 5:27 pm

Water always takes the route with the least resistance.

Your circulator pushes and pulls the water round the system over coming the resistance of the pipe and bends but given the chance the water will take the easy route.

The plumber deals with this by partly closing some or all of the valves to balance the system and to share the heat as required.

This doesn't always work, if it has been cold and valve positions have been altered.

Using 10mm pipe can have a problem when the hot water also feeds the hot water tank if a motorised valve has not been fitted just before the hot water tank.

One solution is to fit thermostat valves on all radiators, when each room reaches its set temperature the valves close and the water is shared by the remaining radiators.
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Postby ryangas09 » Tue Sep 20, 2011 9:50 am

simply if you have run another 2 rads from an existing rad with 10mm pipework there is not enough bore for the water to circulate to all 3 rads
put in this way its very easy to understand

the radiators are not receiving enough water flow to heat the radiators sufficently and they are also taking heat away from the primary rad from which they are taken

the best way to run the 2 new rads is go to the manifold and add a T peice before the manifold so you have a pipe which branches off into 2 then add another 28mm/4x10mm manifold which will accomodate the 2 new radiators
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