Water heaters obviously serve an important purpose. Without one, you wouldn’t have hot water for showering, washing dishes or doing your laundry. That being said, it is important that you set your water heater to the correct temperature since many issues can occur if it is too hot or too cold. If you’re not sure how hot your water heater should be set to, here is a guide to recommended temperature settings and also how to adjust the setting.
Water Heater Temperature Recommendations
There is some disagreement between various experts as to how high you should set the temperature on your water heater. The EPA recommends that you always leave the temperature set at exactly 120 degrees. This is so the unit uses less energy and reduces the risk of being scalded. On the other hand, OSHA and many other organizations recommend that the temperature is always set to 140 degrees instead. The primary reason for this is to ensure the water is hot enough to aid in cleaning and sanitizing.
At Green Energy Mechanical, we typically recommend to our customers that they set their water heater to between 130 and 140 degrees. The only exception is if you have small children at home. In this case, you should always leave your unit set to 120 degrees to prevent your kids from accidentally being scalded.
Even though your water heater can go as high as 160 degrees, we never recommend going above 140. Anything above this temperature is overkill and will greatly increase the risk of scalding. These high temperatures also cause your heater to run more often, which will lead to higher energy costs and shorten the unit’s lifespan.
You should also make sure that you don’t set the temperature too low. Setting your water heater below 120 degrees can be extremely dangerous. If the water isn’t hot enough, bacteria can begin to grow inside the tank. Legionella, the bacteria that causes Legionnaire’s disease, and other harmful microbes thrive in warm water and can quickly colonize the inside of your tank. The only way to prevent this is to keep your water heater set to at least 120 degrees, so the water is hot enough to kill any bacteria.
The temperature setting plays a major role in determining how much energy the unit uses. The general rule of thumb is that for every 20 degrees higher the unit is set, it will use approximately 10% more energy.
How to Set Gas Water Heater Temperature
Adjusting a gas water heater’s temperature setting is simple and only takes a few seconds. Near the bottom of the unit, you will see the temperature control knob. To adjust the temperature, simply turn the knob to the desired setting.
The only problem is that most units don’t list the temperatures for each setting and instead use symbols or letters. Luckily, most brands and models use the same standard symbols.
The first two settings will be marked “Off” and “Pilot,” and these are fairly self-explanatory. Off turns the unit off, and Pilot is used when relighting the pilot light. The next two settings are usually marked with a dot and then a triangle or labeled “Low” and “Hot.” The setting marked with a dot or as Low is usually set to around 90 degrees. However, this setting should never be used as it will allow bacteria to grow. The setting marked with a triangle or labeled Hot should be 120 degrees, and this is the lowest setting you should ever use.
Above this setting, you should see four additional settings. These are usually labeled A, B, C or 1, 2, 3, and the last setting is always “Very Hot.” The A or 1 setting should be around 130 degrees, B or 2 is 140 degrees, C or 3 is 150 degrees and “Very Hot” is always 160 degrees. Again, we never recommend setting the unit above the B or 2 setting to prevent scalding.
Your water heater may have an additional “Vacation” setting after the “Pilot” setting. When you turn the unit to Vacation mode, it won’t ever turn on and start heating. However, a small amount of gas will continue to flow to keep the pilot light lit. This way, you won’t need to worry about relighting the pilot when you get home. All you’ll need to do is adjust the temperature setting.
Adjusting an Electric Water Heater
To set an electric water heater’s temperature, you’ll need to remove the cover from the access panel near the bottom of the tank. This is usually held in place with a few screws. Once the cover is off, you may also need to take out a small piece of insulation to access the control panel. From there, you can turn the temperature control to the desired setting with a screwdriver. Once finished, make sure to replace the insulation and reattach the cover.
Tankless Water Heater Temperature Adjustments
Adjusting the temperature on a tankless water heater is the same as adjusting the temperature on your thermostat. Tankless water heaters have a digital control and display that allows you to raise or lower the temperature by pressing the arrows up or down.
Possible Reasons Your Water Is Too Cold or Too Hot
If you’re having issues with your water being either too hot or too cold, it is likely that either the temperature control is faulty or there are issues with the heat exchanger. It could also be that there are electrical or gas supply issues preventing the unit from heating or that the pilot light isn’t lit. These are always the first things to check.
You may also want to use a kitchen thermometer to measure the temperature of the hot water flowing out of your tap. Before measuring the temperature, you should first refrain from using any hot water for an hour or so to ensure the water inside the tank is at its hottest. You will then need to turn the tap on to hot and let the water run for a minute or two so you can get an accurate measurement of exactly how hot the water is. If you try to measure it immediately, the temperature will be lower as the water inside the hot supply lines quickly cools when your tap is off.
If you have your unit set to “Hot” and the water temperature measures below 120 degrees, you can try to turn it to the next highest setting to see if this helps. When doing so, you will need to wait at least an hour or two before measuring the temperature again. This allows the unit enough time to fully heat the water to a higher temperature.
If the temperature measures higher than what you have the unit set to, you will want to turn it to a lower setting and call a plumber to have your water heater inspected. This problem usually indicates that the temperature control has failed, which can cause the unit to run for too long and heat to a higher degree than it should.
Professional Water Heater and Plumbing Services
If your water heater is having any issues, you can trust Green Energy Mechanical for any repairs. We service and maintain all brands and all types of water heaters, including both traditional and tankless units. Our professional plumbers also specialize in leak detection as well as frozen pipe, faucet and toilet repairs, and we also work on sump pumps. Our team of HVAC technicians can also take care of your heating and air conditioning systems and handle any repair, maintenance or installation needs. We work on furnaces, boilers, central air conditioners, heat pumps and ductless mini-splits, and we serve customers in Canton and throughout the surrounding areas. To schedule a water heater inspection or any HVAC or plumbing service, contact Green Energy Mechanical today.
Restore your water heater with fast and professional services from Green Energy Mechanical Inc. — call 877-564-9279 today!
Author Bio:
Jonathan Neves
Worked in the HVAC industry since he was 17. He started as an HVAC service technician for commercial buildings and eventually came into the residential market because of his love of working with people. He believes that what really sets Green Energy Mechanical apart is how long they stand behind their work and how compassionate his employees are for their clients.
