Hot Water Heater Temp?

taylorgeo

We installed a new hot water heater a couple of months ago, and the water gets super hot before we even get to the halfway position on the sink and tub levers.

Do you think the temp is set too high, or just not used to a new, properly fuctioning hot water heater?

Dave Carpentier

If you have a cooking thermometer, run hot for a while into a coffee mug in the sink and check the temperature. Really hot water is definitely a risk for scalding, you can burn before your brain says "hey, move out of there"
Adding:
120f = 2nd/3rd degree burns in 5 minutes
140f = 2nd/3rd degree burns in 5 seconds
160f = 2nd/3rd degree burns in 0.5 seconds

We keep ours 140-145 at the tank.

Ironman

I’d say you need to dial it down some. Or else put a mixing valve on the tank.

Jamie Hall

I'd go the mixing valve route, @Ironman -- less bacteria, more hot water.

EBEBRATT-Ed

120 at the faucet is what you're looking for with or without a mixing valve.

Try setting the tank to "hot" not "B" as @Ironman suggested

hot_rod

Two schools of thought on WH temperature, set it around 120F and it is safe for use at the faucets. Elevating it to 140F gives you legionella protection potential, and turns that 50 gallon tank in to an 80 gallon drawdown capacity if you add a mixing valve and set it at 120F.

Know that the elevated temperature operating option will shorten the life a bit and cause more mineral precipitation if you have hard water. You may notice that on glasses when they come out of the dishwasher or glass shower doors, more spotting and white deposits.

Larry Weingarten

Hi, Water heater controls are not precise at all, but you should have roughly ten degrees F between calibration marks. What temperature you want at the tap is affected by who's using hot water. If you just have healthy adults, you may want 130 because that's hot enough to greatly slow down Legionella and get away from before being scalded. If you have any old, young, or immune compromised people, 120 or even less is appropriate. In that case, I would keep the tank hotter and use a mixing valve, so you're not being too hospitable to the bugs.

Yours, Larry

Chris_L

Yes, it is set too high.
I've got that same valve on the water heater for a rental unit. It is set between "Low" and "Hot." (Closer to "Hot.") I am sure I would hear about it if it wasn't hot enough.

taylorgeo

I finally checked the temperature utilizing the coffee mug/food thermometer method.

I am at 157 degrees at the kitchen faucet. Do I simply turn that black knob to lower it?

Larry Weingarten

Hi, try turning it down about three marks on the controller and see what temperature you get then 😉
Yours, Larry

PC7060

Chris_L said:

Yes, it is set too high. I've got that same valve on the water heater for a rental unit. It is set between "Low" and "Hot." (Closer to "Hot.") I am sure I would hear about it if it wasn't hot enough.

What Chris said, mine is set at 3/4 of range from low to hot.