We have many homeowners ask, “should I turn off my water heater when not in use?” And our answer is always a no. It is unwise to turn off the water heater when it’s not operating, unless you’re about to go on an extended vacation lasting at least a month.
Continue reading to learn why turning off electric water heater when not in use (or even a gas water heater) is not a sound idea.
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Is It Sound Advice to Turn Off the Water Heater When Not In Use?
Many homeowners ask if turning off gas water heater when not in use (or even an electric water heater) is sound advice. And it is easy to understand their concerns.
Almost everyone wants to minimize expenses. And if families can save hundreds of dollars monthly, they can use the savings on more essential household matters.
The US Department of Energy says the average American family spends about $400 to $600 yearly on water heating, accounting for about 14 to 18 percent of their energy expenditures.
So, will turning off water heater save money? After all, not using the appliance equates to not consuming natural gas, propane, or electricity. It should lower energy expenditures.
Yes, you can save money. However, the savings are not substantial (at least for some families).
For example, suppose you live in Phoenix, Arizona, with a 60-gallon electric water heater that has a 92% Uniform Energy Factor (UEF). You will only save about $1.36 daily. Your savings are only 76 cents per day if you have a similarly-sized gas water heater with 67% UEF.
Hence, your maximum savings in a month are only $40.80 for electric water heaters and $22.80 for gas versions.
The longer you do not use the water heater, the more substantial the savings. So, if you will only leave the house for a week, you will only save $9.52 (for electric units) or $5.32 (for gas versions).
But then, these savings are for Phoenix households, where the cold water going into the heater has a higher temperature than the natural water in colder regions (i.e., New York).
Heating water from 40 degrees to 120 degrees Fahrenheit requires more energy than heating 70-degree water to 120 degrees. It explains why northern families pay more for their water heating than southern households.
Water consumption is also a factor. In general, larger households consume more water than small families.
Some families might get substantial savings when they turn off hot water heater units when the appliances are not in use for a long time. Others might only see modest savings in their energy bills.
Unfortunately, modest energy savings are only a part of the bigger picture. Potential water heater problems await.
Why Shouldn’t You Turn Off Water Heater When It’s Not In Use?
Homeowners will save more money when they prevent their water heaters from undergoing multiple “on/off cycles.”
The energy expenditure of a water heater not used for long time is lower than the energy requirements of continuously raising the water heater’s water temperature.
Turning off the water heater for short periods will only produce modest energy savings. For example, shutting down the electric water heater at night will only save you two dollars monthly or 6.7 cents daily.
Another reason we do not recommend shutting off the water heater when not in use is the absence of hot water when you return.
Imagine returning from work, and you needed a warm bath. Sadly, you will wait at least 20 minutes for the water heater to heat the water to your preferred temperature.
Old water heater models might also have difficulties turning back on after being shut down for several days. They cannot handle the electrical load, potentially damaging themselves. You will end up with costly repairs or replace the unit altogether.
When Should I Turn Off Water Heater?
We can think of three instances when turning off the water heater makes perfect sense.
1. The water supply is off.
Turning off cold water supply to water heater requires shutting off the water heater. The risk of tank rupture and explosion is high if you keep the appliance running even though the tank is empty and the main water supply valve is off.
This should also answer the question, will a water heater explode if turned off?
2. Water heater leaks – It is unsafe to fix any leaks with the water heater running.
3. Going on a vacation
It is always sound advice to turn off the water heater when on vacation, but only if you will be away for at least a month. We will explain in the following section what you should do with your water heater when you go on vacation.
What Do I Do with My Water Heater When I Go on Vacation?
We mentioned that it is best to turn off the water heater when leaving the house for extended periods. So, what should you do with your water heater if you go on a week-long vacation?
First, check your water heater for a “vacation” mode or a similar feature. This technology puts the water heater on an energy-saving mode, allowing it to use as little electricity or gas as possible without turning off.
Second, if your water heater does not have a built-in VAC mode, turn water heater down to around 50 to 70 degrees Fahrenheit.
This trick prevents the water heater from heating and maintaining the water to the preferred 120 degrees Fahrenheit. It does not have to work very hard to keep the water warm.
Moreover, it should help you save more on energy bills without turning off the water heater.
Tips to Lower Water Heater Cost
Most families turn off their water heaters when not in use to minimize energy costs. Here are other tips to reduce your water heating expenditures.
- Minimize standby heat loss by wrapping your water heater with the most thermally-efficient insulating material. This trick will save you seven to sixteen percent of your annual water heating costs.
- Reduce the temperature rise (the difference between cold water inlet temperature and desired in-tank water temperature). 120 degrees Fahrenheit is usually sufficient, so there’s no need to warm your water to 140 degrees. This method will save you an extra four to 22 percent yearly.
- Observe periodic draining and flushing of the water heater to prevent sediment and mineral buildup. These deposits can impact water heater performance. Removing them should help lower your heating costs.
While these tricks can help you reduce your energy expenditures, shutting off water to water heater units and turning off your appliances when away for extended periods should also help you save on bills.
We have a straightforward answer to the question, should I turn off my water heater when not in use? Turning off your water heater is not a sound decision, especially if you will only be away from home for less than a month.
The savings are modest, but the potential problems of restarting the water heater might be greater than what you are ready to accept.
Moreover, many modern water heaters now have a “vacation” feature to keep them running on energy-saving mode, saving you more while letting you enjoy instant hot water upon your return.
As the founder of Usawaterquality, I have been working to deliver quality advice on utilizing water components for numerous households. Here, we believe that water quality is the most critical part of health care, so the investment and attention for the water system will never go to waste.