Downstairs radiators only get warm when i turn off upstairs radiators

[Dazzer-b]

Hi.
Turned my heating on for the 1st time today, i bled every radiator as haven't done it since last winter.
upstairs worked fine but an hour or 2 later I noticed downstairs was still cold. I looked for some advice online and turned the trv's off and locksheilds for the upstairs only and eventually downstairs did warm up.

I then thought I need to balance everything so I've now opened all TRVs and locksheilds fully to work out the order they heat up. Again upstairs is fine but downstairs is cold again.

Any ideas?

 

[Marcin]

You should have not touched the lockshields. Even a tiny move can create a big difference.

Now you can balance the entire system, but before, I would take the downstairs rad outside and bang/flush it until perfectly clean inside. In my home it did not help - I had to change the 20 years old lockshields.