how can i get radiators hotter?

It could be the system is out of balance.Try turning all the rad valves down to closed position then open each 1 to half a turn. the valve which is the hottest on each rad is the flow valve. starting with the rad furthest from the boiler open flow valve until enough water flows thru to make rad hot. Do this with all the rads, it takes a long time to get right and you may need to go thru the whole process more than once, some may even need the return valve adjusting open more as well.. Good Luck

Nev
January 2010