Hi all I am another who has found this through some googling! I have kettling in my system. I had it a couple of years back and I got a frined (BG Eng) to come round and do a full flush for me. He said that it should be good enough and that a powerflush shouldnt be necessary due to the fact my house is only (now) 5 yrs old. Before I bought the house a new rad had been installed as part of a conservatory build, which my mate suggested had too smal a connecting pipe used and therefore it restricted the flow. It is also the lowest rad in the house and when he cleaned the system it actually took a good hour or so of trying to force the water into said rad. When the water did finally get into it loads of black sludge came out, as did every other rad to be honest. I cant quite remember if it cleared the kettling, but in the last few months it has come back worse than ever. I called out BG the other week as I have HC plan with them, and the enginerr stated a flush would sort it out, and even after I told him a frined of mine is a BG eng and had flshed it thru a few years back he still claied its the water quality doing it. He opened the rad to add some inhibitor into it, and in fairness the water was considerably dirty again, though upstairs rads are fine. The inhibitor has had no effect whatsoever. I am trying to contact my mate again but he is really busy so Im just waiting for him to get back in touch. So, all Im doing is asking for some opinions on my best course of action. I see it as: 1 - Get BG to do it 2 - Get another company to do it 3 - Get my mate to do it again, but maybe hire a powerflusher myself Unless someone has another way? Thanks in anticipation Stan