Jadnashua
Retired Defense Industry Engineer xxx
FWIW, where I live, a tempering valve is not optional...it will not pass an inspection unless there's one installed. Now, that doesn't mean it has to actually be adjusted to cool things down, and the better ones are essentially pass-through when at or below the set point, but they do allow you to set the tank hotter and still be safe. Having one installed also lets you make the tank look bigger if you have a house full of visitors for the weekend. This has nothing to do with anti-scald valves at the shower...those just prevent a hot surge caused by a momentary drop in the cold water pressure. It's not uncommon for someone to flip the valve to max hot, and wash their hands, and it could easily get WAY too hot before you finish...this is more the reason for limiting the max water out of the tap, not a bathing issue.
Today's shower valves have two functions (they are not always set correctly, though)...the anti-scald function you cannot turn off, and a mechanical temp limiter you set up based on your current water temps. Unfortunately, that can change a bunch between winter/summer - the hot supply will likely be the same, but the mix with the incoming cold can make it way off in one season or the other, or you live with it technically, out of code.
Today's shower valves have two functions (they are not always set correctly, though)...the anti-scald function you cannot turn off, and a mechanical temp limiter you set up based on your current water temps. Unfortunately, that can change a bunch between winter/summer - the hot supply will likely be the same, but the mix with the incoming cold can make it way off in one season or the other, or you live with it technically, out of code.
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