I have a gravity fed system and cannot get 3 of the 5 upstairs rads to get hot at all. Not even the pipes leading to them are getting hot. Having spent hours reading various threads on this site and running around with a spanner I still haven't got to the bottom of this problem.
The boiler (glowworm flexicom HX), Pump, and control valve and water tank are less than 18mths old
I have removed TRVs ALL pins are okay, I have tried to balance system by opening values 1/8 to 1/4 turn until rads get hot. Also bled all rads until water comes out.
All radiators downstairs and 2 of the upstairs ones get very hot !!!
Other than checking the header tank level can anyone suggest anything?
The boiler (glowworm flexicom HX), Pump, and control valve and water tank are less than 18mths old
I have removed TRVs ALL pins are okay, I have tried to balance system by opening values 1/8 to 1/4 turn until rads get hot. Also bled all rads until water comes out.
All radiators downstairs and 2 of the upstairs ones get very hot !!!
Other than checking the header tank level can anyone suggest anything?