Is the hot one on the intake side ?
Yes. Flow side gets hot.Is the hot one on the intake side ?
I would take the rad off and replace with a section of pipe and run to see if all ok. While the rad off turn upside down and squirt a little fairy in the intake side then run the hose on it but not too high to see if clean. I know it been cleaned etc but one thing is it's like any loose sludge left in the system is building up in a bottle neck in this rad. I'd try the system without this rad in to see if ok.
If you can try piping the out pipe from where the bleed valve is instead.
What make Rad is it ?
View attachment 175226 Sorry i no artist.
Creates a diffrent flow for the rad.
Silly question but is the rad fitted the right way up. It maybe an internal baffle issue . Have another look at the instructions for the fitting and check that was done correctly.
Strange one this. Was it a new fix or replacement rad. Does the pipe work come upto the rad correctly.
Take the rad off and connect the valves together using a length of barrier (plastic) pipe, with inserts nuts and olives.
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