How Long Will It Take My Water Heater To Heat Up?

You shouldn’t have to wait long if your water heater is working correctly. Today, we’re going to discuss how long it takes for different types of water heaters to heat up. We will also go over what to do if your water heater is taking too long to heat up. Read on to learn more.

Gas heaters take 30 to 40 minutes to heat a tank of water. This is less time than electric heaters, which take 60 to 80 minutes. Solar heaters take the longest because they rely on sunlight for energy. You will need to wait 4 to 6 hours on a sunny day for solar panels to heat a tank of water.

How Long Does It Take Different Water Heaters To Heat Up?

There are 4 different types of water heaters: gas, electric, solar, and tank heaters. The main difference between these heaters is how they provide heat. Let’s take a closer look at each of these heaters.

Gas Heater

Gas water heaters take 30 to 40 minutes to heat up. This sounds like an awfully long time to wait for hot water. However, it doesn’t mean you have to wait that long.

There is water stored in the tank that gets heated by this heater. If the tank is emptied, it will take 30 to 40 minutes to fully heat the new water that fills up in the tank. This allows homeowners to have hot water on demand.

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The tank usually will only run out of water if it’s being used a lot at one particular time. For example, if you run the dishwasher and then jump in the shower, you may lose the hot water. As long as the water isn’t being used excessively, the gas heater will help you maintain hot water without having to wait.

The average size of the water tank for gas heaters is 40 gallons. This can hold up to 330 lbs of water.

Electric Heater

Electric water heaters take 60 to 80 minutes to heat up. This is the amount of time it takes to heat an average size 40-gallon tank. These heaters are more common in smaller homes that don’t have high water usage.

Although electric heaters do take longer to heat a full take of water, many homeowners prefer using them. This is because electric heaters are more energy efficient than gas heaters. The extra time they take to heat up can be worth it in the long run, especially if you don’t empty the tank often.

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Electric heaters are easier to install, allowing most homeowners to take the job on themselves. Gas heaters usually require a professional installation that costs more.

Solar Heater

Solar heaters need 4 to 6 hours of sunlight to heat a tank of water. These water tanks are generally smaller than the ones we mentioned above. The average size for a solar heater water tank is 26 gallons.

Keep in mind, this time frame is for sunny days. On days with an overcast, you can expect it to take longer. The water heater takes anywhere from 6 to 9 hours to heat up on a cloudy day. That’s why people that have solar panel heaters are more conservative with their hot water usage.

Solar Heater

You may be wondering how long this hot water supply will last. Most households can make a 26-gallon tank of water last for 2 days. However, there is no guarantee that it will last that long. That is why most homeowners that invest in solar panels will also have a backup heating source for water.

Tankless Heater

Tankless water heaters heat up instantly. These are completely different than the other types of heaters we’ve mentioned today. However, you can purchase either gas or electric tankless heaters.

You can think of tankless heaters as an in-demand heating source. The other type of heaters we mention today keep a tank of water heated up for when the homeowner needs it. How it works is, there’s a device in the pipes that heats the water as it passes through.

Now, tankless heaters heat the water up faster than the other heaters. However, they don’t provide the water instantly. You can expect to wait up to 15 seconds after turning the water on for the water to be delivered.

Comparison Chart

Are you wondering which water heater is the best option for your house? Let’s take a look at how efficient each of these options is.

Time To Heat WaterProsCons
Gas Heater30 to 40 minutesFast heating source, affordable to operate, reliable heatNot energy efficient, expensive to install
Electric Heater60 to 80 minutesEfficient heat source, easy to install, safeHigher heating bills, slower heating time
Solar Heater4 to 6 hours (sunlight)/ 6 to 9 hours (overcast)Free source of energy, environmentally friendly, no fossil fuelsLonger wait time, weather-dependent, takes up a lot of space
Tankless HeaterInstantlyHot water on demand, no running out of hot water during a shower, saves spaceInconsistent, not able to use during a power outage

What To Do If Your Water Heater Isn’t Heating Up

Is your water taking longer to heat up or not heating up at all? We know how frustrating this can be. The good news is, this is a problem you might be able to solve DIY. Below are some of the ways you can fix a water heater that isn’t heating up.

Disconnect The Cold Water Intake

If your water heater isn’t working, you should disconnect the cold water intake into the water tank. This will stop cold water from flowing into your water heater. To do this, you will need to shut off the lever valve on the water heater.

You can find this valve on top of the water heater. To disconnect the water, turn the lever valve so it’s perpendicular to the pipe. Give the lever valve a quarter turn to get it in this position. You should also open the pressure release valve on the tank.

Replace The Heating Element

You may need to replace the heating element if it’s no longer working. Luckily, this is a relatively easy repair that most homeowners can DIY within 30 minutes.

  • What you need: protective work gloves, Philip screwdriver, element removal socket
  1. Put on your work glove before you begin.
  2. Go to the circuit breaker panel and turn off the power to the water heater.
  3. Use the steps listed in the above section to turn off the cold water intake
  4. Attach a hose to the drain valve and run it outdoors to an area where you can drain the water heater.
  5. Run the hot water from a faucet inside the house.
  6. Open the drain valve to allow the water heater to drain.
  7. Only drain the entire water tank if you’re replacing both heating elements. If you’re only replacing the top element, you can partially drain the tank.
  8. Unscrew the access cover on the water tank and carefully remove it.
  9. Fold the insulation back so you can access the heating element.
  10. Loosen the screws that are attaching the heating element to the water heater.
  11. Disconnect the wires.
  12. Use the heating element socket to unscrew the element from the tank.
  13. Pull the faulty heating element out of the tank.
  14. Insert the new heating element into the tank and make sure you secure it in place.
  15. Reconnect the wire and fasten the screws. Fold the insulation back up and reattach the access cover.
  16. Close the drain valve and remove the hose.
  17. Put the pressure relief valve back in the closed position.
  18. Turn the cold water back on.
  19. Turn off the faucet running hot water.
  20. Turn the water tank power back on on the circuit breaker panel.

Check Wire Connectivity

Faulty wiring can prevent a water heater from working. You can check the wire connectivity from the junction box on top of the water heater. In this area, you will find a red wire and a black wire. There will also be a green screw with the ground wire attached. If these wires are connected to other colors or have a white wire attached this could be the problem.

You should also check the wiring in the heating element. If you recently replaced the element, a wire could be loose from the terminal it’s attached to.

Replace The Thermostat

The thermostat in your water heater will need to be replaced if it’s faulty. Experts recommend replacing both the thermostat and heating elements at the same time. Here is what you need to do.

  1. Turn the power to the water heater off from the circuit breaker.
  2. Disconnect the wires from the terminals on the heating element.
  3. Remove the faulty thermostat from the water heater using a screwdrive or your fingers.
  4. Carefully insert the new thermostat. Ensure the wires are connected to the correct terminals.
  5. Make sure the thermostat is resting against the heater so it works properly.
  6. Set the thermostat for your desired maximum hot water temperature.
  7. Reattach the water heater’s cover panel.

Relight The Pilot Light

If the pilot light goes out, the water won’t heat up. This is a common feature in gas heaters. You will need to relight the pilot light to begin heating the water again. Here is what you need to do.

  1. Ensure that the gas is turned on.
  2. Set the thermostat control and the gas control on the water heater to the pilot position.
  3. Hold down the control and repeatedly press the spark ignitor until you get a flame.
  4. Continue holding the control button for approximately 90 seconds while it heats up.
  5. Release the button and set the gas control to the on position.
  6. Adjust the dial to the temperature you want.
  7. This may take multiple tries to work. If you don’t succeed, wait ten minutes and try again.

Replace Your Fuse

If your water heater fuses continue to blow, you will need to replace the fuse. Before you do this, we suggest turning off other appliances in the same area of your home. This will prevent the new fuse from being overloaded when you turn it on. Here is what you need to do to replace a fuse.

  1. Turn off the power on the main switch.
  2. Locate the fuse that supplies power to the water heater.
  3. Remove the fuse by unscrewing it.
  4. Make sure the new fuse is the same amperage. If it’s too high, you can cause damage to the panel.
  5. Fasten the new fuse in place.
  6. Restore power to the fuse box from the main switch.

Replace The Circuit Breaker

You may need to replace the circuit breaker if it keeps tripping and affects the hot water. Here is what you need to do.

  • What you need: new circuit breaker, safety glasses, screwdriver, flashlight
  1. Turn off the power from the main switch.
  2. Use the screwdriver to remove the cover plate from the circuit panel.
  3. Locate the breaker you want to replace and switch it to the off position.
  4. Carefully pull the old breaker out of the panel. Disconnect the wires from the circuit.
  5. Attach these wires to the new circuit.
  6. Insert the new circuit into the slot where the old one was kept.
  7. Fasten the cover plate back on the panel.
  8. Turn the power back on.


Tankless water heaters are the only type of heater that will instantly heat the water up. Gas, electric, and solar heaters all take time to heat up the water in the water tank. However, they heat up enough water to last for an average of 2 days. This allows homeowners to have hot water on demand.

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