How Long Does a Water Heater Take to Heat Up?

How long does it take for a water heater to heat up, and what factors affect the amount of time taken?

Find out everything you need to know in this guide.

⏱ How Long Does It Take For A Water Heater To Heat Up?

The time it takes for a hot water heater to heat up depends on the type of heater you own.

Some heaters, like tankless water heaters, provide hot water instantly. Others, such as most tank-based water heaters, take around 40-80 minutes on average to heat up a batch of water before it can be delivered around your home.

As an overview, the average heating times for the different water heaters are:

Heater Type	Heating Time
Electric hot water heater with tank	60-80 minutes
Propane (gas) water heater with tank	30-40 minutes
Propane (gas) tankless water heater	0-15 seconds
Electric tankless water heater	around 0-15 seconds

These are the times it takes to heat cold water that’s newly entering the heater. So normally, even with a tank-based water heater, you won’t have to wait as long as the times mentioned above because the tank will already contain some hot water ready for when you need it.

However, if you use all the water in the tank in one go (such as if you run a bath or have multiple hot water-using appliances and fixtures on the go at once), you’ll have to wait the full time for the tank to refill and heat, meaning you’ll be left with cold water until this happens.

📋 Water Heater Types & Average Water Heating Times

Below, we’ve shared the different types of hot water heaters and their average water heating times, assuming that they’re new and properly sized for your home:

Gas Tank Water Heater

A gas tank water heater is a heater with a tank for storing and heating water. At the bottom of the tank is a gas-fired burner, which typically uses propane to heat the water. The tank fills from the bottom upward, and the hot water leaves the tank through a discharge pipe.

The average time it takes for a gas hot water heater with a tank to heat water is 30-40 minutes from an empty tank.

Gas Tankless Water Heater

A gas tankless water heater is a gas-powered water heater that operates on demand, rather than using a tank. When you turn on a hot water faucet or fixture, water flows through the unit’s heat exchanger, where a gas burner heats it up before it’s delivered instantly to the point of use.

The average time it takes tankless gas water heaters to heat water is 0 seconds. You might have to wait 10-15 seconds for the water to reach the faucet or fixture in your home, depending on the size of the water pipes and the distance it has to travel.

Electric Tank Water Heater

An electric tank water heater is a more energy-efficient alternative to a gas water heater with a tank. This heater uses high-voltage electric heating rods that heat water from the center of the tank outward.

On average, an electric water heater with a tank takes 60-80 minutes to heat water before delivering it to your appliances and fixtures. Electricity might use less energy to operate, but it’s not as effective as gas for heating water, so the process takes longer.

Electric Tankless Water Heater

An electric tankless water heater is exactly the same as a gas tankless hot water heater, except it uses electric elements to heat water instead of a gas burner. This water heater is also designed to deliver hot water on demand.

Like tankless gas water heaters, tankless electric water heaters heat water instantly, but it may take 10-15 seconds for this hot water to arrive at your fixture or faucet.

Solar Water Heater

A solar water heater is a type of water heater that uses solar energy to heat water. This type of water heater is ideal for homes in regions with long hours of sunlight throughout the year, but it’s usually installed alongside a backup water heater so that heated water can still be delivered when the solar heater can’t be effectively used.

Depending on the type of solar water heating system you buy, it could take as little as a few seconds to receive heated water from this appliance.

📊 Factors That Affect Hot Water Heating Time

Here are the key factors that affect how long it’ll take for your water heater to heat up:

Type Of Water Heater

The main factor that determines hot water heating time is the type of water heater you own.

If you have an electric or gas tankless water heater, it’ll take just seconds for you to receive hot water after turning on your faucet or showerhead.

If you have a tank-based heater, you’ll either have access to hot water straight away from the tank, or, if the heater is starting with an empty tank, you’ll need to wait 40-60 minutes on average for the entire tank to heat up before you have hot water access.

Temperature Rise

The water heating temperature setting and the temperature of the initial water supplying your home will both affect the temperature rise – the total degrees by which the heater must heat your incoming water to achieve the desired water temperature.

The greater the difference between the incoming water temperature and the desired hot water temperature, the longer the heating process will take.

If you want to speed up heating time, reduce your water heater setting to a slightly cooler temperature, which will require less work from the heating elements to achieve.

Water Heater’s Tank Size

The size of your water heater affects the flow of water through the heater and (for tank-based models) the volume of water in the tank.

If you have a tankless gas heater or electric heater, the bigger the heater size, the faster it should heat and deliver hot water to your fixtures and faucets.

If you have an electric or gas tank heater, a larger water heater tank capacity will take longer to heat. That’s because there’s a greater volume of water to heat.

Distance From Water Heater To Fixture

The distance of piping from the water heater to the fixture it’s supplying hot water to will also affect the time it takes to receive hot water.

Once water has been heated, it must travel from the heater through the pipes to your faucet, appliance, or showerhead.

The longer the distance between the fixture and your hot water heater, the longer it’ll take to receive the hot water.

Water Heater Age & Condition

The age and condition of your water heater affect its heating efficiency.

Older water heater models weren’t built as efficiently as they are today. Plus, due to natural wear and tear over years of use, your water heater will gradually lose efficiency until it reaches the point of near-breakdown.

Most water heaters last 10 years on average, so if your heater is older than this and is struggling to perform as it should, consider buying a replacement model.

Pipe Diameter

The diameter of the pipes traveling from your water heater to your home’s fixtures will have been determined when your home was first built, based on the number of bathrooms in your home and your expected water demand.

The larger the pipe diameter, the faster the delivery of hot water to your fixtures.

So, while the diameter of your water pipes won’t affect water heating time, it will affect how long it takes for the hot water to be delivered to where you need it.

📖 How To Speed Up Water Heater Hot Water Delivery

Been caught in one ice-cold shower too many? There are a few options to consider that should help you to access hot water faster in your home.

Buy A Heater With A Bigger Tank

If you’re tired of having to wait upwards of 60 minutes for heated water after using all the hot water in your heater’s tank, look into upgrading your tank capacity.

You might have bought your home with a water heater tank size that was ideal for two people – but now you’re a family of four, and your water demands are higher.

To avoid spells of cold water, speak to your local plumber about buying a bigger tank capacity for your heater, which will mean you’ll have more water to use whenever you need it.

Swap To A Tankless Water Heater

Ultimately, regardless of their tank size, there’s no avoiding the fact that tank heaters might run empty, increasing your likelihood of being supplied with cold water while you want for a new batch of water to heat.

👨‍🔧 If you’re done with tank water heaters completely, consider buying a tank-free water heater replacement.

Tankless water heaters give you hot water on demand whenever you need it, and they’re becoming more and more affordable as their popularity increases. Contact your local plumber if you want an idea of how much one of these systems will cost.

Install A Hot Water Recirculating System

A hot water recirculating system is a plumbing system that rapidly sends heated water to your fixtures and appliances.

Although these systems don’t speed up the actual heating time, they do speed up delivery time because they use a pump, rather than relying on water pressure.

The biggest benefit of a hot water recirculating system is that water from your heater is ready to use faster, so you don’t need to run the tap as long – which, in turn, saves you time, water, and money.

📑 Final Word

So, the answer to “How long does it take for a water heater to heat water?” depends on your heater type.

If you have a gas or electric water heater without a tank, you can enjoy hot water instantly. These systems are superior to gas or electric water heaters with a tank, which take upwards of 1 hour to heat water from empty.

If you hate having to wait for warm water, consider installing a tankless heater in your plumbing system.