Cold radiators, again

[PeteN]

Open vent CH and HW system. HW ok but the rads not heating up. Started with the d'stairs ones not working. Cleaned out with product via expansion tank. Replaced pump, then 3-way valve. Seems to be air in system, so installed auto air separator to replace manual vent by cyl. Directing all flow thru one d'stairs rad doesn't help. Just moved in so no history. Help?!!!!

 

[corgiman]

sounds to me like you valve is not playing the game

can you see it it is usually by the cylinder and most probably has a silver head?

 

[PeteN]

Have changed the valve and watched it open and close. It seems to get hot on the CH side when called for and also on the HW side, but if both are called for most heat goes to the HW side. The rads don't get warm even when the feed pipe from the valve is hot. Any ideas?

 

[doitall]

Have changed the valve and watched it open and close. It seems to get hot on the CH side when called for and also on the HW side, but if both are called for most heat goes to the HW side. The rads don't get warm even when the feed pipe from the valve is hot. Any ideas?

Sounds like you have fitted a divertor valve and not a flow share.

Whats the number on the case.