how to refill heating system after being drained down?

that all depends on your installation, can be easy, can be a b*tch!

turn on your filling loop, open all automatic vents, wait for boiler pressure to rise to 1-1.5bar, turn off filling loop, bleed all radiators of air, turn on rise pressure again, repeat until all air is gone and pressure is 1-1.5 bar, if it doesnt work you may get a plumber out as some systems can air lock in strange places...

T
June 2008