adding bigger pipes to 8mm system

[alan999]

"Sorry it gets warm. We know heat is getting there and with the radiator off there isn’t any restricted flow from either pipe that we can see.
Starting to wonder if giving a chemical clean might be an idea."

I was thinking if the pipe only got luke warm you could eliminate a problem with the radiator. If the pipe got really hot a smaller radiator might be a much cheaper option. Perhaps a 1.4 x 50cm single.

 

[D_Hailsham]

Which boiler do you have (make and exact model)?

 

[Terrywookfit]

Not 100% sure. Hunks are encased in plaster
Think maybe 8-10m from manifold.



Wouldn’t that flag on other radiators as well though? It’s just this one that’s a pain.

That is one hell of a run for a 2.4 kw load on 8mm.....!6 to 20 m.
The rule of thumb on site we used for 8mm was ( 8000 btu max with 20ft run of pipe …10 ft flow +10 ft ret ).
We often ran 15 mm to the drop point to achieve this.
The available head on a combi is very unlikely to overcome the resistance to get enough flow.

 

[ianmcd]

if replacing the existing 8mm pipe to 15mm is doable,then do it, it will not affect the other rads is balanced properly