Freezing 3yr old son's bedroom HELP!

[Sparkgap]

All downstairs rads are fine except the front room, which is some 6m from the manifold on 10mmm microbore. The manifold feeding this rad is a JG Speedfit Inline Manifold 4 Port unit.

My Q is, would a 12 m loop, 6m there and back feeding a 1kw rad be OK on 10-mm microbore or shoudl I consider upgrading this pipe to 15mm to help get increased flow to this rad? The issue of getting heat to the rad has never been there - always high 60-s at inlet, just no flow through the rad so huge temp drop and little heat.

Before anyone says it, I know I could have got a GS engineer to look at this weeks ago, but this is now a point ot principal for me that I, with your help, will fix this!

Thanks as always for the feedback.

1kW should be okay on 10mm. Wondered if there might have been a problem with the pump not being man enough for the job but the change between 10 and 15mm in terms of pressure drop isn't a lot and if it's 22mm up to the manifold should be plenty. Just a thought, if you can get at the return manifold and check its temperature to see if there's any issues. Even more stupid thought: they haven't taken both F&R conns to the front room rad off the same manifold have they? I have seen it done....

 

[smglasgow]

Just checked and flow and returns are correctly plumbed at manifold. Measured length again and closer to 10m each way! Also noted none of the microbire pipework is insulated, so yet another to do job or is the heat loss through 10mm microbore not worth worrying about? Will be draining the sentinel soon, so could run a new 10mm returrn pipe to the prob rad, if a 20m loop is feasible on a 1kw rad. Thing just aint comin up to temp despite hot inlet, New valves and a flushed radiator (taken to garden with hose). Either blocked return or pump not up to the job I guess, but then it pushes water round the other 15 rads ok.

 

[Stigster]

Do you have access to the whole pipe run on the problem rad? Could the 10mm pipe have been pinched or squashed somewhere?