Drained a bit of water out of my central heating system today in order to add a cleaner (Header tank installation)
Shocked to find I couldn't bleed any air our later. Other rads sucked. I found that the ball valve wasn't letting in water. I fiddled a about with the plunger (it is a plastic one) and eventually it worked.
Is this common?
Will turn off the water tomorrow and dismantle it - in a really awkward location though. Must have been easy for the builders before the roof was fitted!!