How Long Hot Water Heater Will Stay Hot Without Power

Water heating is a heat transfer method that uses an energy source to heat water above its primary temperature. And the term ‘hot water heater’ exactly refers to a device or appliance that produces ‘hot water.

Consumers of hot water keep wondering how long will a hot water heater stay hot without power? Actually, the answer is associated with various factors like the tank size of your water heater, where it is located and insulated, and mainly how you use your hot water supply. 

Electric power can be restricted for some reasons. The following instructions can assist you to make up your mind about if your hot water supply will stay hot during a power outage.

How Long Hot Water Heater Will Stay Hot Without Power

Services of water heaters without power

You may see numerous water heaters in the market or online shops. To keep the water warm depends on the type of water heater.

  • Water heater based on electricity: This heater can’t give water without electricity. Electricity is a must because it runs on it. This gives you hot water quickly. But if the power is off, it stops working immediately.
  • Water heater based on gas: If your water heater runs on gas, you may have hot water all the time because gas is needed to heat the water, so no electricity is required. For pilots, it requires electricity. It can store water in a tank. You can work out anytime or take a bath in warm water.
  • Fuel, heat coil, oil, solar, or indirect water heaters: During a power outage, whether or not your water heater will work depends on whether it relies on electricity or not. The easiest way to assess this is to check if the water heater has any connection to the power outlet.

If your area has a power outage issue, you need to select your home water heater more carefully. For further advice, talk to your experienced local plumber to pick the best water heater to meet your expectations.

How the water tank keeps water hot

Most hot water tanks are made of carbon steel, stainless steel, copper, etc. Copper is a very expensive metal, so stainless steel is being used as a cheaper alternative. And there are many advantages associated with stainless steel tanks. One of the major benefits is the reduction in the risk of erosion. Stainless steel wears a bit more than copper and can keep the water tank free from debris for a long time.

However, as long as the tank has a good insulating jacket, it will keep the water warm all day, without the need for constant reheating. You may use a timer to heat water for an hour or two every day just before you need hot water.

How long water heater will stay hot without power

It is quite obvious that electric tankless water heaters won’t work without an electrical supply. However, water heaters without gas and propane tanks also rely on electricity and cannot work without electricity. For example, to require a shower during an influence outage, your home must be equipped with a standard tank-style tank. So yes, if you have a water heater in the tank and the electricity goes out recently, you probably better take a bath.

Experts say that the standing water in your heater may remain hot for less than 2 days. Basically, it reckons with the container’s size. If your tank is large, it will lose heat soon and if your water tank is small in size, the result will be vice versa. Besides, the temperature consistency is also affected by the quality of the water tank including the insulation quality.

Conventional tank water heaters

Basically, the only chance to maintain an uninterrupted hot water supply during a power outage is if you own a conventional gas tank water heater that only runs on pilot lights. If it has no connection to the electrical circuit, there won’t be any interruption in the power of the heater and it will continue.

If your electric water heater is a conventional tank heater, this is your only option. You will have a reserve supply of hot water to pull from your tank for a limited time.

The solution to having hot water during a power outage

If you are trying to find heated water while the power is off? I have shared some necessary tips that can help you in keeping your water hot for a particular period of time. Please check them below –

  • Size: If you use a larger tank, you can save a lot of water. You can use  the stored hot water for various purposes. It can stay warm longer during power off.
  • Precise insulation: Insulating the water heater is required to keep water hot without electricity. Probably you can face some issues with insulation such as it may stop working. So do proper insulation for keeping water warm without any problem.
  • Placement: The placement of your water affects the temperature of the standing water. For example, if you place your water heat between the two interior walls, it will keep the water hotter than the garage set.
  • Age of water heater: The modern water heaters have got a new component that is more effective for heating water for an extended period of time. If you are using a worn water heater, you need to replace it soon.


How long will the water stay hot in a water heater without power?

Mainly depends on (1) the setting of the core temperature before the power is turned off and (2) the insulation amount of the tank. However, it can certainly provide warm water for a limited time. You can expect the water to stay warm for about an hour or two.

Can you have hot water without electricity?

Yes! You can use gas or other fuel instead of electricity as a burner. But you can not run it without the electrical power. However, choose the heater according to your preference. 

Do you need electricity for hot water?

Yes. Electricity is a must for operating water heaters. Gas operated Water heaters also need electricity for heating water. Whatever the fuel you use to heat the water, you’ll need an electric connection for the operation. Electric power is the main key to using a water Heater for getting hot water. 


We need hot water in our daily life. You might be thinking, How long will a hot water heater stay hot without electricity? With some caution, you can fix this problem quickly. 

If your home has frequent power outages, you should buy a conventional gas tank water heater. It will supply hot water without electric power and save you from trouble. To properly install a water heater, contact a skilled plumber. And you may continuously get warm water even without an electric power connection.

Have an awesome winter enjoying the warm water, thanks, buddy.

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