don't get a new mixing valve, just get the element.
I had no hot water and thought there was a problem with my domestic HW coil, however when i touched the downstream of the coil and almost melted my skin, i realized the coil was working, but it was the valve not letting the hot water through.  So initially i took my mixing valve out and was looking for replacements, but realized i could just change the element inside.  I took some steel wool and polished my current one to get me by for a few days while i waited for this one to come in and instead of paying $120 for a whole valve, i got this for lass than half the price.  The problem with the old one was that it was just covered in junk and wasn't properly reading temperature and for safety was keeping hot water from flowing through.  There is no need to ever get a new mixing valve, just this element and the O-rings are what should be replaced.  It's also very simple to change, just be careful of the hot water when you drain it.
Rating: 5 stars