The Hydropath HS38

British Gas came to service our boiler today. They didn’t actually fix the problem it’s currently having, but that’s another story. One of the recommendations made by the engineer was to fit something called a Hydropath HS-38. Here’s the leftlet he left, complete with price:

It “could” save me money, it says here, and “could” also mean my system and household appliances last longer. And the back promises more still – it could also cut my energy bills, because “1mm of limescale can make your boiler 10% less efficient” – according to a claim from, a domain that redirects back to Hydropath, who sell the device (the URL is not working, but if you correct the / to a dot it goes here, where the same claim is provided without a source).

And speaking of working, just how on earth does it work anyhow?

The Hydropath Technology system induces an electric current at AM frequencies (between 100 and 200 KHZ) up and down the water flow for ranges of hundreds of meters.

The transmission is carried out with random breaks in fading sinus waves so that the entire range of salts in the water can be treated. The Hydropath Technology electric field produces crystal nuclei in a saturated solution, as well as in unsaturated solutions. This process attracts charged ions and forms stable crystal nuclei.

…The size of the crystals are between .05 and 50 microns and they flow in the water as a suspension without settling on the walls of the pipe. As a result, there is a decrease in the level of the saturated solution in the water, triggering a process in which the existing limescale in the pipe system is dissolved until the lines are completely clean.

More here. And yes, I think they mean sine wave, not sinus. But anyhow. When presented with an interesting-sounding leaflet, and a flashy animation showing how it could remove all the scale from our heating pipes (similar to this one from the website), I was intrigued – surely there would be some kind of certification or independent testing to back up these claims. And indeed the website provides this report.

It’s fairly fascinating. Strangely some pages are marked as “Revision 1”, but others are not and the program description page says “Revisions None”, although that could refer to the test methodology. It doesn’t explain what outcome was to be considered a success, only what would make it a failure, and that seems to differ between the Executive Summary (flow below 1.0 gallons/minute), the program description (flow of water falls below 0.9 gallons/minute) and the End of Test Parameters (when flow decreases below 0.9PPM). PPM and gallons/minute are not the same measure.

The photos included don’t show a useful set of comparisons between the control and test units, and the charts – which have slightly different axes, for some reason – show temperature, not flow, but apparently flow was the criteria for stopping the test (they also seem to show that the control device was heating the water slightly more, whatever that might mean).

So. Quite interesting. And I can get one fitted for £155. Two questions spring to mind.

One is: “I wonder if it really works?”

I think the answer to that is “I’ll never know, because even if I bought one I couldn’t measure the results”.

The second is: “Will I pay £155 for one?”

I think the answer to that is “no”.

All © 2022 Tom Royal