DHW Tank Temp

28W

I've read that 140 degrees is recommended to prevent growth of legionella bacteria. On the other hand, I've also read that at high temps the DHW will get mineral build up faster.



Any recommendations about DHW tank temp? i don't have children in the house so accidental scalding is not a concern.

Zman

140

I set mine just over 140 off and about 125 on. I use a thermostatic mixing valve at the heater to prevent scalding. Many of the newer exchangers are designed to reduce mineral build up. I have good lick with Triangle Tube Smart and Heat-Flo.

Carl

hot_rod

how is your water?

if you have hard water, temperatures above 140F does seem to make a big difference in the mineral precip.



If you can supply enough HW with the tank at 140, good enough. I think most of the newer tanks are limited to 140F in the control.



140F is a bit hot to send to the faucets, ideally a listed thermostatic mix valve would be installed at the tank.

ChrisJ

temperature

What about possible growth within the piping AFTER the mixing valve?  You would need a mixing valve at every fixture in order to prevent growth and yet still protect people from themselves.



I realize there are certain requirments and codes, but honestly someone would have to hold their hand in 140F water for 5 seconds in order to get burned.  5 seconds of pain is an awful long time and would, in my opinion have to be deliberate.  Of course there are times when I go to wash my hands after the wife just washed a pot and sure, it hurts for a second but it doesn't actually burn me.



Just my opinion on the topic.





28W, sorry for getting off of your original question,  If your water isnt bad I personally wouldn't be too concerned.  I run my WH at 140F give or take, just keep on eye on on your anode rod(s).