Re: Washing machine - waste pipe limescale

[IMM]

In the house I'm renovating, some genius has plumbed for a washing

> machine so that the waste water has to travel about 25 feet, round > three bends, to reach the drains. > > As we live in a hard water area, the waste pipe has clogged up with > lime-scale, which is difficult (read "impossible") to reach manually. > > Be grateful for some help: in particular, is it poss to use any > chemical to clear the limescale which won't eat through the plastic > waste pipes?

Replace the pipe and re-install with a sharper fall to the main stack. Is the end of the pipe vented? Or is a spring operated valve used and end capped off?

[Charles M Atkinson]

I'd use vinegar, preferably a strong pickling vinegar, heating it before pouring it in. Or maybe a commercial kettle de-scaling product that doesn't need boiling.

[Bob Minchin]

Taking lots of care, you can use hydrochloric acid as sold by swimming pool suppliers. Dilute from the supplied concentration to between 5 &

10%. Allow for the level to foam up and have a bucket of water handy to dilute any spills and overflows.

None of the common acids you will be able to buy will eat through PVC pipes