If your water seems unusually cold, the problem may be a broken heating element or poor insulation rather than the temperature of the water heater itself. A qualified plumber can help diagnose and repair a faulty water heater. [2] X Research source

On the majority of gas water heaters, the lower temperature range will be somewhere around 90–110 °F (32–43 °C), while the upper range will top out at around 140–150 °F (60–66 °C). The dial on your gas water heater may not be numbered, which can make finding the perfect temperature a little tricky. One simple way around this is to take the temperature of the water a few times after altering your settings, then tag the exact degree reading or mark it on the dial itself. [4] X Research source

Hotter temperatures are more effective for eliminating most common bacteria, including health hazards like Legionella, E. coli, and staphylococcus. [6] X Research source Avoid setting your water heater to a temperature higher than 120 °F (49 °C). Doing so can present a serious risk of burns, especially for children and the elderly. [7] X Research source

Keep in mind that your water won’t get as hot, which may impact your comfort or the level of sanitation for cleaning projects.

Don’t attempt to make any alterations to your water heat before double checking that the power is safely off. If the breaker for your water heater isn’t labeled, it may be necessary to use a multimeter to test for a live current. You’re looking for a reading of zero volts. Don’t forget to tag the correct breaker when you’re done. [10] X Research source

On some models, there may be a separate plastic cover beneath the metal access panel. This should come away easily with a gentle tug.

The insulation inside a water heater is used to reduce heat loss and ensure more accurate readings.

The adjusting screws on newer electric water heaters feature indicator hands which tell you approximately how hot the current setting is. Pay attention to where the hand rests, as this will allow you to fine-tune your water temperature more precisely. [15] X Research source If your water heater makes use of dual heating elements, make sure both thermostats are set to the same temperature so that one isn’t forced to do more work than the other.

It may take up to an hour for your running water to reach its maximum temperature after having your unit shut off for an extended period.

For the most accurate reading possible, it’s best to use a container that’s been kept at room temperature.

Write down the number you get for reference. It can help you work out the ideal temperature range for your home, or point to potential heating issues outside of the unit itself. If you don’t place the thermometer in the water right away, the water may have a chance to cool down enough to throw off your reading.

Increase your water temperature in 10 degree increments to reduce the risk of scalding.

Take care of any necessary adjustments before everyone in your home begins their daily routine.