can hear the difference when pump turned up or down, so hoped that means it's working. It was yesterday. system was all fine until the new cylinder. bled radiators - no air. perhaps it's time to have a bosh at flushing out the rads?!
I have a nightmare of an old heating system, finally got the rads balanced as best as I could then old cyclinder leaked right through living room ceiling and had to get an emerg plumber in to replace it. He did it, finishing 1pm-ish today. It's now 6.55pm and there's very little heat going...