manifold/microbore system problems

28 Dec 2005
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United Kingdom
8mm microbore flow & return pipes into one valve only. 3 out of 6 rads will work the others do not. Due to this strange valve configuration I stripped and cleaned the rad, valve and length of pipe attached to the valve which inserts into the rad and flushed the rads. reassembled all & refilled the system without success....Possible microbore blockages and if so the best possible solution to clean through. Bent microbore??? Manifold failure ??? 12 outlets on one manifold presumably 2 x six rads but all on one 22mm single pipe (returned) both into and out of the cylinder. Could the rads be Knackered and require replacement??? On one occasion I tapped a valve and the rad came on albeit the valves are simple and now clean and appear to be ok?? Any other tips or assistance would be appreciated.. :) NOTE **** The hot flow is getting to the valve in all instances but not heating the rad and susequently no return.
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You have twin entry rad valves. Make sure the return is connected to the side of the valve with the tubular insert, otherwise the flow will short-circuit.

Check that both pipes and the valve are clear, especially the lockshield side of the valve. This may need opening (remove cover) to clear any blockages.

As for the manifold, this has a closure plate internally so it is in effect two separate manifolds (one flow, one return) of 6 connections each.
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successful at last... the manifold was clogged up. having stripped it from the system i them power jetted it through and hey bingo... all rads in top form.. thanks for your replies

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