Review by Technical Thug (on 7/10/2016)
If you have ever wished that your shower would not suddenly become icy cold or scalding hot because someone else in the house started running hot or cold water in the sink, or wished that you could adjust the flow rate without also changing the temperature, this valve from Hansgrohe is your solution. Better engineered than anything US-made, you set your temperature and the valve will hold what you set, to the point of temporarily shutting off the flow altogether if that's what it has to do to prevent you being scalded.
The Hansgrohe also includes another safety feature, a stop on the temperature control that prevents you from accidentally knocking the control over to 'scalding hot'. You can override the safety stop if you want hotter water for once, though. It comes preset to 100°F, but you can adjust it so that the safety stop falls right at your desired temperature. If you like to shower at 104°F, you can set the stop at 104°F.
The honest truth is all shower valves should be thermostatically controlled like this one. It's a simple matter of safety as much as it is one of comfort. When you buy a Hansgrohe thermostatic valve, you're buying that safety, as well as buying quality that puts anything from any major US plumbing brand to shame. Sure, the Hansgrohe valve is more expensive than a product from the names you're used to. But it all depends on what your priorities are. Do you want to buy a level of quality, or shop down to a price? If you're looking for the cheapest possible parts as long as it works at all, try your local big box hardware store, and good luck. But if you want a solid, dependable valve designed for your family's safety and convenience, buy a Hansgrohe thermostatic valve.