Recommended Thermostatic Shower Valve For Hard Water

2 Feb 2016
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United Kingdom
Is there a specific type or recommended brand of thermostatic shower valve for hard water areas?

I can see there are different types of valve cartridge:
  • bi-metallic
  • brass body wax
  • plastic body wax
I'm wondering if one type is better than the others as our current shower has failed within a year and a replacement cartridge (brass wax) isn't going to last much longer. I'm assuming the issue is limescale although its a cheap shower.

If I am going to get a new shower I might as well try and get one that can cope best in hard water areas.
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The bi metallic will be the worst, as they are usually integral to the body of the valve the other two are separate items that act on another part of the shower valve and are usually sealed

Very Hard water will always cause issues with any type of thermostatic control/shower due to the nature of it's construction. That being said, it's more likely to cause an issue on what the thermostatic cartridge acts upon, rather that the cartridge itself in the case of the wax elements.
The round-knob Aqualisa design is very durable.
Cheap showers dont last, I'm in a hard water area and the 'cheap' Triton I initially fitted has been problematic since the start. Stripped it down several times, was better for a while, but didn't last. Eventually needed a new cartridge as wouldn't stop dripping, I opted to change it for a Mira, which has quickly proved to be a far superior shower.

Mira spares are usually pretty good as well, remember installing numerous Mira 88's as an apprentice in the late 80's, the service kits are still available.
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You'll find many pro plumbers and gas installers buy a cheap as chips bar mixer and just replace them every 5 years or included. The last one was £25. With the rip off spares prices from the big names stuff 'em.

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