Water Heater Temperature

Are you looking for water heater temperature information?

The guide below will show you how to check and adjust your hot water heater temperature on both gas and electric residential storage water heaters.

You may be surprised to know that while the EPA (Environmental Protection Agency) recommends setting your water heater at 120 degrees, OSHA (Occupational Safety & Health Administration) recommends setting your water heater thermostat at 140 degrees under certain circumstances. If you would like to read more about OSHA's recommendations go to osha.gov/dts/osta/otm/legionnaires/faq.html and scroll down the page.

What Temperature Should I Set My Water Heater?

Water heater manufactures recommend setting your water heater temperature at 120 degrees to help prevent scalding and to save energy.

Scalding is a real concern if you have small children or elderly in your home. Single handle faucets can lessen the chance of someone getting burned.

If you have an older dishwasher that doesn't preheat the water, recommended water heater temperature is 140 degrees. This is to ensure clean sanitary dishes.

Basically you'll need to adjust the temperature to suit your needs or your budget. I know a gentleman that lives alone and keeps his water heater set at 110 degrees.

About water heater settings

Because heat rises (yes, even in water) the water in the top of a water heater can be much hotter than the water in the bottom. This is especially true of a gas water heater where the thermostat and burner are located at the bottom of the tank.

Water heater settings or temperature settings are not constant temperatures. A thermostat set at 120 degrees may let the water cool to as low as 110 degrees before it begins heating water. In turn it may heat the water as high as 130 degrees before it stops heating.

How To Check Your Hot Water Heater Temperature

Allow your water heater to set an hour unused before checking the temperature.

You can use a candy or cooking thermometer to check your water heater temperature. Go to the faucet nearest the water heater. Run the hot water for one full minute ( this will heat the water pipes and give you a more accurate reading ). Fill a coffee cup from the faucet and read the thermometer.

Gas water heater

If you have a gas water heater
you're in luck as far as adjusting
the temperature.
There's nothing to remove or
replace.

Simply turn the dial located
on the front of the gas control
valve.

The warm setting will be in the
90 to 110 degree range.
The hot setting will average 140
to 150 degrees.

Electric water heater

Turn off the water heater breaker.
Remove both access panels (upper
and lower) if you have a double
element water heater.
For single element water heaters
remove the lower panel.

Pull the insulation to the side
or remove it so you can see the
thermostat.

Remove the plastic cover if
it doesn't have an access hole
for the adjustment screw.

The thermostat adjusting screw
is located at the bottom of the
thermostat, just above the element.

As you can see you'll need a
small flat blade screwdriver.

If your setting the temperature at
120 degrees or above set the upper
thermostat at 120 and the lower at
the desired temperature.
Because heat rises water in the top of the water heater will be heated
by the lower element.

Replace the plastic cover(if you removed it). Place the insulation
back over the thermostat and element. Replace the access panels
and turn the power back on.

If after adjusting your water heater temperature you're having
problems you might want to check the water heater element testing page and/or the water heater thermostat page.

Return from water heater temperature to water heater repair guide