Hi Andrew,

All the TRV's are set to open- maybe I should check that some are not
stuck closed? I'm not actually sure how the pipes are set up- each
downstairs rad has a pipe coming down from the ceiling and one going
back up- I kind of thought there would be 'horizontal' pipes
downstairs?
All other valves are open.
The pipes leading to the rads are all cold.

thanks
Charlie