I want to had a mixing valve to my indirect got hot water tank. I picked up a watts valve. It says you need to be 12" below the exit of the hot water line out of the tank and have the cold a the bottom, i guess to keep the valve not in the hot water. I never seen it done that way? I draw on the photo how i was going to pipe it. what do you guys think? I could come right out of the tank straight and put in a shutoff and drop down to the mix valve and then tie back into the line before the existing shutoff.




If the mixing valve is at the lowest point, do I need to have a drain on the line to drain it out?

To install this mixing valve do I need to drain the tank? Is it a good idea?

thanks

 

Interesting. Can you post the model number for the valve.

 

the number is 3/4lf1170m2-us

 

Since a mixing valve is normally used to lower the hot water temperature (input to output), why not start at the furnace control and lower the temperature of the water in the closed loop between furnace and indirect heater? In your photo showing the mixing valve connections, shouldn't the red pipe be connected on the tank side of the shutoff valve?

 

Lowering the system temperature is one way of supplying hot water without a mixing valve.
The problem with this method is the recovery rate needs to be considered. If the system cannot recover hot water fast enough then it needs to be kept hotter and mixed cooler for domestic use.

To prolong the life of the valve, it is recommended the valve be trapped as shown......

Installation pdf link
That installation is too prolong the life of the valve. I have the feeling that the trap keeps the crap out of the valve which will reduce clogging. I'd recommend the valve actually shown in the diagram as it uses unions which makes it replaceable. I personally would not use solder-in type.