DIY Doctor UK DIY Forums

My 10-year-old plastic small-bore radiator supply and return pipes seem to be the cause of sludge due to old age, resulting in permeability. Will the modern double-wall barrier piping now available be a long-term cure if I have it installed, or is copper the only worthwhile investment? I have seen claims that hep20 flexible barrier pipe has a 50-year Guarantee !!

You know sometimes on this site, I get the “feelingâ€

I am sorry to give the impression that I am a student of plumbing. In fact I am a retired nuclear power technologist on just 3/4 of a UKAEA pension, and cannot afford to be stung again by central heating maintenance costs. I had sludging before, and scrapped one large radiator on that occasion;- followed by renewing a motorised valve, controller, thermostat, and now, with 3 cold radiators fed from above, plumbers are telling me I have duff old plastic pipes that need to be scrapped. A rough idea of cost is a mind-boggling £1000-1500, just for pipes of lhe modern kind of plastic to be pulled thro'. I cannot just have a power-flush done, and repeat it 5 years later at £467 each time. The piping problem has to be cured now, forever;- Megabucks cannot be magicked-up again later in my Government-enforced retirement. Is the modern small-bore plastic just as prone to sludge as the old stuff, just because of bore-size, which was once the reason some plumbers preferred 15 mm copper;- I went for small-bore plastic for ease of installation, and did not ask for, or get advice. I AM VERY MUCH IN NEED OF ADVICE NOW !!

The reason your getting “slugâ€

Thank you ' Peter the plumber. ' 15 mm copper is confirmed as my only long-term option. Fernox protection was definately used at installation, and after the new radiator was fitted, as I supplied all parts from my sister's Builder's Merchants Business, and saw the work being done and kept the used fernox containers. I am currently trying the William Wilson brand of system cleaner, which I put in myself, after draining just one radiator+header tank;- 4 weeeks quoted for de-sludging old systems. I am not very hopeful as I have already tried the Fernox brand concentrated desludger, which I injected into that same cold radiator in the kitchen, a month ago. My friendly plumber has a poor opinion of that concentrate. The original choice of plastic was mine entirely, without any comment from my sister or any plumbers;- My team of jobbers just did as they were asked, but later did other systems the same. The plumber who fitted the replacement radiator,and refilled using fresh Fernox, said he would not have used small-bore of any material, just 15 mm copper to and from the radiators, and larger copper elsewhere.

Just a note to Peter, On a recent trip to the States was advised
that most fitters dont use copper untill the leads, plastic pipe is used more now than ever before. Britain is so far behind.