We had major sludge in our heating system, nothing happened when you turned on the heat. We paid to have the system flushed by a gas safe engineer, but it wasn't done thoroughly. The heating barely worked and then the combi boiler, which was only about 6 years old, broke. We had a new boiler installed (by the same guy but don't get me started on that) and the system was flushed again at that time.
Then when we started using the heat the new boiler immediately broke. We had it fixed under warranty but they said we had a sludge problem and needed a powerflush, so we argued with the engineer until he came back and spent another half day doing manual and powerflush. The heating was working a lot better then but a few weeks later the hot water stopped working properly (heat plate sludged up apparently), and the boiler company says we need another powerflush before they'll fix it again under warranty.
Now, we don't want to pay for another powerflush only for the cycle to repeat again. No-one will tell us whether our very old radiators are causing this problem, they just say, 'we can replace your radiators if you want, for this much...' so my first question is, would replacing the old radiators be likely to solve our sludge problem?
Secondly, if we replace them ourselves does is make sense to run something like Sentinel x400 through through for a while before putting on the new radiators? Or is possible to run chemicals through just the pipes with the radiators removed?
And lastly, is it advisable to use a cleaner like that on a very old system?
Thanks very much!