I'm interested in fitting a water-softener (specifically, the Twintec S3, which is a dual-cylinder unit developed in the UK, apparently) to my home. My home is over 3 stories, with a bathroom on the middle floor and an en-suite on the top floor.

The bathroom has a toilet, basin, and (large - 180cm x 80 cm) bath. The en-suite has a shower, basin, and toilet.

Hot water is provided by a combi-boiler; I think it's an Ikon 23t or something similar to that.

I don't know the specific flow-rates of things, but... if the water softener has 2 cylinders of 17 litres each, how will I not run out of water during long showers or filling up the bath? This specific water-softener is supposed to regenerate in 10 minutes, and is supposed to be able to regenerate while the other cylinder is supplying. But... If a tap runs at 5l/min, and a cylinder holds 17l, then one cylinder will be drained after ~3m20s. Then the other one will be too, shortly thereafter.

Am I missing something? Do I have the cylinder-size wrong, or the regeneration-time...?

  • Impossible to answer w/o flow rates. Commented Aug 27, 2012 at 19:39

1 Answer 1


As Evil said impossible to tell you from the info you have provided, but if you look at the specs of the Twintec S3 it runs at 65l/m max flow rate and uses 17L per regeneration cycle ( eg wasted water)


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