Baffled by cold rad - Not sludge. maybe blockage?

[denso13]

What ideas do you have has to how else I can clear the restriction/blockage?

Are the manifolds or main flow and return accessible? How far to the problem radiator? A bit of work but you could try temporary feeds in 10mm plastic just ran on the surface to see if it helps.

Got to start problem solving somewhere.

 

[BlueLoo]

Yes the system has mostly worked fine for the 7 years we’ve been here.

Couple of years ago I cleaned the gauze in the boiler return pipe as it was rusted up once and we lost all heat downstairs. Put it all back together, added some inhibitor and it worked fine.

This radiator always used to be the first to get red hot downstairs.

In April this year I first noticed it wasn’t getting hot and fitted a new valve on it, balanced all the rads and tried a lower strength chemical flush. Also checked the gauze in the return pipe again.ba

Then spring came and I left it until the autumn….

"Balanced all the rads"

Give the rad enemas a go.
You migt be surprised and it's no harm.
Then, if you've got Trvs, open up all the lockshields (delete the balancing).

Basically start fro scratch. You might get it going.

I tried cleaning mine with chemicals. I then took the rads off and my jaw dropped at the **** that came out of them.

 

[SE82]

Are the manifolds or main flow and return accessible? How far to the problem radiator? A bit of work but you could try temporary feeds in 10mm plastic just ran on the surface to see if it helps.
Got to start problem solving somewhere.

No they’re not accessible. I’ve no idea where they are. Possibly in the cupboard floor where the hot water tank was.
Problem rads are about 18-20metres from the boiler.

I feel I’m pretty good at DIY for a girl and willing to tackle anything but this is starting to feel like a big job???