3 way mixing valve and 150 degrees to extend hot water?

[Tyler Howell]

Need a new water heater and a 50 gallon is the biggest that will fit in my rental. Can't install a tankless due to weather and elevation (according to mechanic). He recommends installing a three way mixing valve and cranking the temp up to 150 to extend amount of hot water available. Anyone done this before?

[Mike F.]

I think he means a thermostatic mixing valve. The plan would be to install it so you can mix cold water into the hot water line coming out of the hot water heater to reduce the temperature of the water going to your fixtures in the house from the 150 degrees coming out of the hot water heater. 

With the changes to hot water heaters due to the recent EPA regulations problems with fitting the newer larger hot water heaters into old spaces is creating a need for more creative solutions. 

If you can't do anything else then this is a solution that will work, the bad thing is the hot water heater will not last as long as it would at that temperature. 

If you haven't already I would look into a fast recovery hot water heater, more expensive but makes hot water faster than a typical one. 

The thing that makes me wonder though is how a 50 gallon water heater set at normal temperature isn't big enough for a rental?