unable to re fill system after drain down (worcester 24cdi)

[Marlin]

help, the system has been drained down to change a radiator, work completed, fernox injected into rad, key inserted into boiler, filling knob turned on but the system is not filling, water is there but not passing the internal filling loop. help please. thanks marlin

 

[bcollet]

Is this some kind of airlock ?
I had some trouble yesterday refilling mine - it took a long time. I manage to speed it up by bleeding radiator to let air escaping. I realised that I have a aerject valve that seem to slow down the refilling process.
Bertrand

 

[keego]

Sometimes the grey plastic knob can round off the spindle it's attatched to so you're turning the knob but nowt happens, try pulling the grey knob off & turning the spindle with a pair of grips.

 

[Marlin]

thanks... guys it turned out to be sludge in the system
blocking water entry to the boiler a good poke out bid the trick.
rgds marlin

 

[meldrew's_mate]

it turned out to be sludge in the system
blocking water entry to the boiler a good poke out bid the trick.

I am tempted to ask "but what about the Worcester?" but that would be coarse and obvious.

If sludge stopped mains pressure water getting into your boiler (Worcester- ooh-err; see, once you start...) think what it's doing to the other bits of your system. Please have it flushed with a good quality flushing chemical like X400, then refill with X100 or similar.

Don't be in the habit of regularly topping-up either, get the leak(s) fixed that are causing the pressure drops, and the sludging will not return.