The Ideal Water Heater Temperature Setting You may think there is not since everyone enjoys a different heat level when they shower or bathe. However, experts say that, in fact, the best temperature setting for a tankless water heater is about 120°F (49°C), although the default setting is 140°F (60°C).
For most residential uses, a temperature setting of 120° - 125°F is sufficiently hot and will protect against scalding. You can set your residential tankless water heater higher, but know that a child can be burned by 140°F water in just a couple of seconds.
In the US, the maximum legal temperature for a water heater in a residential setting is 120 degrees. Most folks want to run at 125-130 degrees but be careful. The Federal law that stipulates the max temperature is because of folks, especially kids, getting burned by the water.
Tankless Water Heaters: Tankless water heaters, on the other hand, don't store hot water. They heat water as it passes through the system, often with adjustable thermostats ranging from 100°F to 140°F.
Water Heater Temperature Recommendations
120 degrees Fahrenheit is the safety recommendation against scalding, but 140° is the common default setting.
Although some manufacturers set water heater thermostats at 140ºF, most households usually only require them to be set at 120ºF, which also slows mineral buildup and corrosion in your water heater and pipes. Water heated at 140ºF also poses a safety hazard—scalding.
According to Centers for Disease Control and Prevention (CDC), water temperatures ranging from 130 to 140 degrees Fahrenheit(°F) can eliminate most of the harmful bacteria. However, be warned that these high temperatures can also increase the risk of scalding.
A restriction in the air supply or venting system can cause overheating. Flue gases are hot. If something blocks the exhaust, the hot gases might overwhelm and overheat the system. If something blocks air supply, the burner might run hotter than usual and overheat the system.
What Temperature Should a Water Heater Be Set At? Most water heaters are designed to operate safely at temperatures between 120 and 160 degrees. Many tank-style units also have a low-temperature setting where the unit will only heat up the water to around 90 to 100 degrees.
For your safety, Rinnai tankless water heaters come with a maximum temperature default setting of 120℉ to help prevent scalding. However, by following these simple steps, you can increase the temperature to 140℉ if you choose.
Manufacturers often recommend a hot water heater temperature between 120 to 140°F, and there's a reason for this. The Occupational Safety and Health Administration (OSHA) recommends a recommended hot water temperature of at least 122 degrees to prevent the growth of harmful bacteria.
Raising the temperature setting on your water heater ultimately makes your hot water supply last longer. It will ensure everyone gets a hot shower, with plenty leftover to run your dishwasher and washing machine.
Priority Button / Indicator Indicates that this controller is setting the temperature . Priority can be switched to another controller by pressing its Priority Button when no hot water is running. Sound Volume Used to adjust the voice prompt volume. Temperature Display Shows the temperature setting.
Tankless water heaters require you to have a direct connection into the supply and return lines. If plumbing was done incorrectly or a pressure balancing shower valve needs repair, cold water can reach the hot water line, making the hot water lukewarm.
Understanding these settings can help when figuring out how to adjust the temp on water heater units. A typically represents around 130°F. B usually corresponds to 140°F. C indicates a temperature of about 150°F or higher.
Most of the search results said anywhere between 120°F and 140°F is normal, and advised against going hotter than 140.
The best temperature setting for a hot water heater is between 120 and 140 degrees. Below 120 degrees, bacteria can develop in the stagnant water sitting in the tank. Above 140 degrees, the water is so hot that you and your family members can be at risk for scalding in as little as two seconds.
While most recommend that 120 is the best temperature for a tankless water heater, don't fall for the idea that setting it lower than 120 degrees will save money. You can save three to five percent on your energy bill for every ten degrees you decrease the water heater temperature.
Low water pressure can affect the performance of a tankless water heater. A plumbing crossover can cause low water pressure by connecting the cold and hot water lines incorrectly. Installing a pressure regulator can help regulate water pressure and ensure a consistent flow of hot water to the tankless water heater.
Install a Recirculating Pump
With a recirculating pump, the water that travels through your tankless heater no longer sits in the pipes to cool off once you shut off the outlet.
There were two temperatures discussed for each fixture during the design standard meetings. One was the “use temperature” and the other was “the maximum temperature” to prevent scalding. It's generally agreed that 120 degrees Fahrenheit is the maximum safe hot water temperature that should be delivered from a fixture.
If the temperature is above 65°C, then the water will be too hot to use, and it increases the risk of serious burns. Keeping the temperature at a safe level, 60°C to 65°C, makes the water hot enough to use and hot enough to kill unwanted bacteria.
So, What Is the Ideal Shower Temperature? “Luke warm,” says Anolik. Many experts agree the tepid temperature feels slightly warm compared to your body temperature, and falls somewhere between 98º and 105º F.