On Dec 30, 5:33*pm, "Nick" wrote:
Any suggestions for doing so please?
We will be replacing the aged back boiler in a couple of months.
The chap that will do the job has suggested that desludging prior would be a
good idea. I fully agree but don't know how best to do so.
Conventional fully pumped system. Two motorised valves (CH & DHW), TRV's
fitted to all but one rad. Two zones. Will probably replace all TRV's in the
process as they are donkeys years old.
System always has inhibitor, Fernox or Sentinel (can't remember), but hasn't
been flushed for more than 20 years.
I could go for a professional powerflush as I can't do it myself. Too many
years & not enough diy time.
I can drain the system completely and add chemicals. Then drain again, add
more (other,if needed) chemicals and do this repeatedly.
Given that I have at least a couple of months, this seems a good option as I
would prefer to do it myself if at all possible.
I realise that such drastic treatment will show up any potential weaknesses
in the system (rusting rads etc), but now is the time for me to get it done.
I hope this may not cause too many problems.
I have been told that hydrochloric acid might be a good starter and also to
be careful with it. I have a fair quantity of HCL as we use it regularly. I
would not know what rate to administer this at.
Alternatively Fernox DS-40 or similar.
Any thoughts or recommendations would be very much welcomed.
Time is not of the essence, but now is a good time to start.

Best wishes to all for a very happy and preposterous new year.

Nick.

Have a look at this: http://www.youtube.com/watch?v=pYURwv4Ci2A

Protect the system afterwards with Sentinel X100 or Fernox MB-1/Fernox
Protector F1.

So are you not replacing the radiators?