OK, decided to drain CH system to clean it with Fernox restorer and add Fernox protector after clean because I don't believe it's ever been done in the 6 years I've been here. I have a standard Open Vented with F&E tank and 16 rads, two rads downstairs have drain-cocks (on rads I had installed 5 years ago, one in garage and one in conservatory).
I connected a hose to both drain offs, tied up the Ball cock in F&E and opened all bleed valves in upstairs rads - all worked OK and air was sucked in on everyone. Was fairly surprised to see mostly clean water being emptied out of each hose.
Started to bleed downstairs rads which worked OK on 4 of them (the 2 with drain-cocks and 2 older ones), but other five rads just let water out as soon as I bled so my guess is they were not being emptied as none of them were sucking air in? Does this mean they are on a different loop or something?
After draining down and no more water coming out I check F&E tank and it still had a little amount of water in but it was dirty rust coloured so emptied and cleaned tank. I refilled but left drain cocks open to flush system out and water was clear.
I then refilled properly and added Fernox Restorer and will leave for a few days, then will drain again, flush and add protector - but not sure If it will do any good if 5 rads downstairs didn't empty??
I connected a hose to both drain offs, tied up the Ball cock in F&E and opened all bleed valves in upstairs rads - all worked OK and air was sucked in on everyone. Was fairly surprised to see mostly clean water being emptied out of each hose.
Started to bleed downstairs rads which worked OK on 4 of them (the 2 with drain-cocks and 2 older ones), but other five rads just let water out as soon as I bled so my guess is they were not being emptied as none of them were sucking air in? Does this mean they are on a different loop or something?
After draining down and no more water coming out I check F&E tank and it still had a little amount of water in but it was dirty rust coloured so emptied and cleaned tank. I refilled but left drain cocks open to flush system out and water was clear.
I then refilled properly and added Fernox Restorer and will leave for a few days, then will drain again, flush and add protector - but not sure If it will do any good if 5 rads downstairs didn't empty??