• Home
  • |
  • Blog
  • |
  • How to Turn Up Your Water Heater

How to Turn Up Your Water Heater


As an Amazon Associate we earn from qualifying purchases. Learn More.

Turn on a hot water faucet and you expect hot water, but what happens if the temperature of your hot water doesn't meet your expectations? The problem may be as simple as turning up your water heater's temperature. A water heater's temperature is set at the factory, but you may want the water to be warmer or cooler than the factory setting.

Whether your water heater is fueled by electricity or gas, you can adjustment the temperature up or down. Although, not necessarily difficult, the process isn't as easy as turning the thermostat up on your furnace. This article will show you how to change the temperature, and we'll provide you some safety considerations as well that should never be overlooked.

Water Temperature Safety

There are some very serious safety issues to consider when you adjust the temperature on your water heater. The EPA recommends setting your water heater temperature at 120°F, for several reasons: First, 120°F will conserve energy and lower your utility bill; second, the water will be hot enough to prevent most diseases; and third, the water won't be hot enough to cause a scalding injury. 

With that said, 120°F is not hot enough to prevent Legionella bacteria, which causes Legionnaires disease. Legionnaires' disease is a respiratory infection caused by inhaling bacteria from water. Legionella bacteria is killed when it is subjected to 140°F water for 32 minutes.

Clearly there's a big difference between 120°F and 140°F, and since children and older adults can be scalded with water as low as 110°F, the higher temperature offers serious risks beyond Legionnaires disease.

There is, however, a work around that will allow you to have the best of both worlds, or more specifically temperatures. You can add a hot water heater booster to your water heater, which will ensure that your hot water is not only disease free, but it also won't cause scalding injuries.

A water heater booster keeps the water in the tank at 140°F and mixes it with cold water as it's drawn. When the hot water reaches the tap, the temperature drops down to 120°F. Although you can install a booster yourself, you may want to consider hiring a professional plumber to do it for you. Talking with a professional will also help you determine the best option for your situation.

This video explains how a water heater booster works:

Why a Water Heater Runs Cold

There could be a variety of reasons why your water heater is running cool. If your water temperature is significantly lower than expected or you have no hot water at all, this article can help you troubleshoot the problem. 

The issue could be a simple fix, such as replacing a heating element, or it could be your household hot water demand has increased and your water heater isn't able to keep up. We recommend troubleshooting these issues first, in most cases the root cause of the problem is always the best fix.

However, if you simply enjoy a steaming hot shower and your water heater isn't delivering, you can always turn up your water heater. 

Is it Okay to Turn Up the Temperature on a Water Heater?

Water heaters are manufactured with temperature controls for precisely this reason. Although, the temperature is factory set, there's no reason why you shouldn't adjust it to your preference. 

However, keep in mind, that increasing the temperature will also increase your utility bill; and the reverse is also true, when you lower the temperature you will also lower your utility bill.

Many homeowners jump right into turning up the temperature on their water heater, but you should always test the temperature at the tap before making adjustments to ensure that the water isn't too hot or too cold for safety reasons.

Pro and con columns

Pros and Cons of Turning Up the Temperature on Your Water Heater

Before starting you may want to take a look at the pros and cons to making temperature adjustments:


Most importantly, turning up your water heater will give your household the sensation that they have access to more hot water. We use the word sensation because in reality, the amount of warm water your heater produces is the same.

The difference is that when the water is produced at a warmer temperature, most people naturally feel they need less. This is beneficial because it can make your family feel like they can take warmer showers, wash the dishes at a higher temperature, and so on. 

Dropping the temperature on your water heater (to a safe level) will lower your utility bill, saving you money each month. In addition, if you own a gas heater you can easily adjust the temperature to the lowest setting if you're going on vacation.

Homeowners frequently worry about appliances such as dishwashers which require hot water to be at least 140°F. But adjusting your water heater temperature below this point won't impact these appliances since they pre-heat the water.


There are two big downsides to raising the temperature on your water. The first is the increase you'll see on your energy bill. A higher temperature means more energy is required to heat the water, this translates to higher utility costs.

The other concern, as mentioned earlier is safety. You'll need to be careful not to turn up your water heater too high. Small children and older adults are all particularly at risk to scalding, which could happen at temperatures as low as 110°F. Cranking the temperature up above the 120°F recommendation could be particularly dangerous.

And of course, there's the safety concern regarding Legionnaires disease and other bacterias that can grow in your hot water tank and plumbing if the water is too cool.


How to Check Your Water Heater's Temperature

Checking the water heater's temperature is very easy. Here's how:

  • Turn the hot water ON at the faucet closest to your water heater.
  • Allow the hot water to run for several minutes.
  • Fill a cup with hot water and insert a cooking thermometer into the cup. Cooking thermometers are very inexpensive, and if you don't already have one you can order one from Amazon.
  • Make note of the temperature.
Testing water temperature with finger under a faucet

How to Turn Up the Temperature on a Water Heater

The way you adjust your temperature is primarily based on the type of water heater you own. There are three different types: Tankless, electric tank-style, and gas tank-style. In addition, there may be some variations between manufacturers, but they typically operate relatively close. Check your owners manual for details that are specific to your heater.


The majority of tankless water heaters (both gas and electric) have temperature controls located on their digital control panel. Many even monitor the outgoing temperature, which makes the adjustment that much easier. In fact, for the most part, you can raise or lower the temperature the same way you would adjust the thermostat on an air conditioner.

Electric Water Heaters

The majority of electric water heaters have an upper and lower thermostat. The thermostats are located behind two panels on the tank of the heater. Both thermostats will need to be set to the same temperature. Here's what to do:

  • Turn OFF your water heater at the circuit breaker.
  • Using a screwdriver remove the cover to the two access panels. One is located near the top of the tank, and the other near the bottom.
  • Carefully move the insulation aside to locate the thermostat.
  • Find the dial on the thermostat and slightly adjust it using your screwdriver in the direction of either hotter or colder depending on your needs. Both thermostats should be adjusted the same. Unfortunately, each manufacturer labels these differently, yours may just indicate "hotter" and "colder" but if you move each the same amount, you should be okay.
  • Replace the insulation and access panels, and turn the water heater back ON at the circuit breaker.
  • Allow the water heater at least 3-hours before checking the temperature again. Repeat the process if needed. 

Watch the Video

Gas Water Heaters

It's easier to adjust the temperature on a gas water heater because they typically have an easy-to-read dial located outside the tank. Here's what to do:

  • Once you locate the dial, simply turn it to the left or right depending on whether you want to adjust the temperature warmer or cooler.
  • Wait at least 3 hours before checking the temperature of your hot water. Make adjustments as needed.

Watch the Video

Related Posts