"Tim and Steph" wrote in message
news:_HGsf.2020$SW3.663@trndny08...
We have a oil-fired boiler that generates both the hot water and the heat
for the house. My wife is opening a daycare, and per state regulations,
we need to have the hot water at the tap be 120 degrees or less. While
I'm sure it's possible to regulate the temp of the entire system, I can
see problems with simply turning the whole thing down. (e.g. 20 below
zero nights)

So, I'm thinking there must be some kind of valve that does this sorta
thing automagically. Turns out, I'm right - I did a little research, and
lo and behold, I found "Thermostatic Mixing Valves". The perfect thing
for my application!

Then, I saw the price - they're pretty dear! The cheapest I could find
was right around $100, which seems exorbitant for what it is. Which got
me to thinking - why can't I simply throw in a couple of check valves, and
a ball valve that controls how much cold gets mixed with the hot? The sum
total of the parts would be about 20 bucks. What am I missing here?


Remember all the times you have been taking a shower and someone turned on
the water in the kitchen sink or flushed the toilet?