I drained the system to replace the pump with a WIlo, and to add Fernox system cleaner. I will confess that I forgot to drain it in an organised way (ie I didn't open the radiator bleed screws as the level dropped). I had a helluva tussle with the old pump - the valves wouldn't undo, no space & couldn't get my tools on, I had to remove the valves themselves and to do that I had to remove other pipework... It was late when I refilled it and again forgot the bleeding - partly as I was watching for leaks in the airing cupboard. It was 11pm when I got it assembled & running & I was rather weary and I realised that I'd put the pump on upside down and it had run for a short while like that (30 secs to 2 mins, not more). I shut the isolating valves, turned it the right way up and reset the programmer and the boiler didn't fire. The wiring hub wasn't touched.
I've bled loads of air from the system but there are still some gurgles. The primary circuit has a simple run from the boiler downstairs up into the ceiling, along 2-3m then up into the airing cupboard so I'd be surprised if there was an airlock there and it didn't airlock last time we drained the system although I would have been more organised then.
Boiler is a Potterton Promax SL, always been trouble free till now. I've tried various permutations of HW & CH, with the pump on min/max & in between and also run the purge programme several times.
I've since checked the terminals in the wiring hub and they behave as expected when the room stat calls for heat etc.
I've read about crud in the flow switch (which I'd expect to be in the boiler unavailable area and therefore a callout). If this is a possibility, are there any tips for dislodging the crud (there was a LOT of gunk on the Magnaclean)? I'd rather not drain the Fernox out as it hasn't really had chance to do anything, but if it's worth a go, then I will.
Any other ideas? Many thanks.
I've bled loads of air from the system but there are still some gurgles. The primary circuit has a simple run from the boiler downstairs up into the ceiling, along 2-3m then up into the airing cupboard so I'd be surprised if there was an airlock there and it didn't airlock last time we drained the system although I would have been more organised then.
Boiler is a Potterton Promax SL, always been trouble free till now. I've tried various permutations of HW & CH, with the pump on min/max & in between and also run the purge programme several times.
I've since checked the terminals in the wiring hub and they behave as expected when the room stat calls for heat etc.
I've read about crud in the flow switch (which I'd expect to be in the boiler unavailable area and therefore a callout). If this is a possibility, are there any tips for dislodging the crud (there was a LOT of gunk on the Magnaclean)? I'd rather not drain the Fernox out as it hasn't really had chance to do anything, but if it's worth a go, then I will.
Any other ideas? Many thanks.
