How long does it take a 40 gallon water heater to heat up? Many owners of water heaters ask this question every day. The solution to the critical hot water query also relies on. Some tankless water heaters exist. A few people have electric water heaters.

You are probably well aware if you have a tankless water heater that it only heats and provides water “upon request.” Tankless water heaters often take 60 seconds to start up because of this. However, there are also exceptions. On a busy weekday morning, you can have hot water problems if everyone in your household needs hot water.

A gas water heater could need 30 to 40 minutes to heat the water. This endless interval is better than it sounds. Water heaters store heated water and release it through pipes only when users need it. 

Gas heater tanks often have hot water in your gas water heater insulation close to your bathtub or faucet. Most individuals don’t need warm water. You must be able to ter the heater insulation is close to your bathtub or faucet. The strength of the pipe is another consideration.

Expect your electric water heater to operate more slowly than its gas cousin. An electric water heater may need at least 60 minutes to heat the tank thoroughly. If you have any concerns, you should accurately measure the pressure in your water heater.

How Long Does it Take for a 40-Gallon Gas Water Heater to Heat Up?

A heater’s tank capacity may affect how long it takes to heat water. It can take 60 to 80 minutes to heat up if your electric water heater has a 40-gallon tank. Again, gas water heaters are unique. 

They supply hot water more quickly because they perform better in efficiency. It takes between 30 and 40 minutes to heat water in a 40-gallon gas water heater.

How long does a 5500-watt electric water heater with a 40-gallon capacity and a 120-degree setting take to heat up? This electric water heater could need over two hours to heat the water. Usually, this process takes an hour and 45 minutes.

Factors That Determine How Long Your Water Heater Takes to Heat Up

Type, temperature parameters, and size can affect how long it takes to heat water to the appropriate temperature.

It will take varying amounts of time to heat different water heaters since they use various heating components and capabilities.

How Long Does It Take a 40 Gallon Water Heater to Heat Up

More significant effort and duration are needed for larger models. The warm-up time is reduced as the temperature is increased.

Differences Between Types of Water Heaters

The time it takes for a water heater to heat up can be significantly impacted by its kind.

Since electric water heaters use electric coils to produce heat, they often take longer than gas water heaters.

Due to its direct heating method, gas water heaters are faster in heating times and frequently provide hot water in only a few seconds.

Size of the Water Heater

The size of the water heater also has an impact on how long it takes to heat up. To reach the correct temperature, larger tanks need more energy.

On the other hand, smaller versions heat up more quickly since they use less energy.

Additionally, tankless water heaters are instantaneous and do not require filling with water before use.

Temperature Settings

A water heater’s temperature setting directly affects how long it takes to heat up.

Higher temperature settings need more energy to heat the tank to the required temperature, lengthening the warm-up period.

Lower temperatures often need less energy and heat water more quickly.

Distance From The Water Heater

An essential issue to consider is the distance between a water heater and the point of usage.

The farther the distance from the heater, the less hot the water will be when it arrives at its destination since hot water loses heat as it moves through pipes.

Hot water can pass through pipes more or less swiftly or slowly depending on their length and kind.

All pipes must be kept as short as feasible and adequately insulated to avoid heat loss to provide hot water fast and at the right temperature.

Pipe Diameter

The pipe diameter can also influence how rapidly hot water gets to a particular location.

Older homes typically have smaller diameter pipes, which cannot flow water as rapidly as pipes with bigger diameters.

How Long Does It Take a 40 Gallon Water Heater to Heat Up

The kind of substance used to make the pipe can also impact how quickly hot water flows through it.

Water travels through rigid metal piping more quickly than flexible plastic piping.

It is crucial to employ the proper pipe diameter and materials when installing hot water plumbing systems to achieve speedy delivery times and suitable temperatures.


Proper insulation can also considerably impact the time it takes to heat water. Because less energy is wasted by conduction when pipes and tanks are well-insulated, heating water takes much less time.

Your water heating system’s efficiency may also be increased, and the expenses connected with it can be decreased by installing more effective insulation around the tank.

Average Times to Heat a Water Heater

Gas Tank Water Heater

One of the residential houses’ most popular water heaters is the gas tank kind.

With an average recovery rate of 35–40 gallons per hour, a standard gas water heater tank typically heats water in roughly 30 minutes.

The system’s size, age, other characteristics, and external variables like the surrounding temperature and pressure can all affect this rate.

Gas Tankless Water Heater

Compared to a traditional tank water heater, a gas tankless water heater has a much faster average heating time.

The on-demand hot water delivered by a tankless gas heater may save time and energy, frequently taking only 15-20 seconds.

When deciding between conventional and tankless water heaters, it’s essential to consider other aspects, such as the influence on the environment, maintenance, and cost-effectiveness. 

Gas heaters are an excellent option for quick, hot water supply since they are regarded as being more dependable and efficient than conventional designs.

Electric Tank Hot Water Heater

One of the most common water heaters installed in apartments nowadays is an electric water heater with a tank.

Depending on variables including tank size, system efficiency, and ambient temperature, the average heating time for a tank electric water heater is typically one hour.

Because this kind of electric tank water heater utilizes electricity to heat the water kept in its tank, it must remember that it needs a specific quantity of electrical power to function at its best.

Electric Tankless Water Heater

Unlike conventional electric tank units, tankless electric water heaters offer hot water on demand with a bit of wait time.

An electric tankless water heater heats water almost instantly, frequently in less than 30 seconds.

How Long Does It Take a 40 Gallon Water Heater to Heat Up

Compared to traditional electric versions and different kinds of water heaters, this rapid hot water delivery enables higher efficiency.

Additionally, by heating the required water at any given moment, an electric water heater may save costs.

Electric tankless systems give a flexible and practical approach to supplying hot water in any household.

Solar Water Heater

Solar water heaters are a rising trend in residential water heating.

Water in a tank is heated using solar energy panels harvested from the sun.

The size and effectiveness of the solar panel system and the quantity of sunshine available all affect how long it takes a solar water heater to heat water on average.

A solar hot water system typically needs 1 to 2 hours on a bright day to reach total capacity. However, this time can be shortened by investing in a more extensive or more effective system.

Depending on the heater installed, your solar water tank must maintain water warm for at least two days.

As opposed to typical single flat plate collectors, evacuated tube collectors run solar systems at better efficiencies, higher temperatures, and for more extended periods.

Since each of its curved, unique tubes is always positioned orthogonal to the sun’s rays, evacuated tube harvesters are a form of a solar hot water system that solves the problems associated with other systems.

Hybrid Water Heaters

A heat pump water heater, commonly called a hybrid water heater, is an electric heater that has been redesigned with energy efficiency in mind.

The recuperation period for this kind of water heater is often greater than other models—about two hours—even in ordinary settings.

Fortunately, a high-demand mode can cut the wait time to only 60 to 80 minutes.

Common Reasons for a Slow Hot Water Heater

The mineral build-up, a broken thermostat, or a lack of insulation are frequently cited causes of sluggish water heaters.

Hard water can lead to mineral build-up clinging to the heating components and decreasing their performance over time.

A broken thermostat might be unable to gauge the water’s temperature correctly, leading to an excessively extended heat-up cycle.

More extended heating periods will also result from inadequate insulation since heat is quickly wasted without insulation.

How Long Does It Take for Hot Water to Come Back?

The cold water that enters your water heater must be heated before your water heater can produce hot water once you’ve depleted the tank that holds hot water and your shower has gone cold. Recovery Time is the term for this.

An electric water heater typically requires around 70 minutes to fully recover and re-heat a full cold tank to the desired temperature. It will take 35 minutes for a gas heater.

Since your water heater started heating water while draining the hot water, these periods may be shorter. However, if there is a lot of demand, it will take almost as long as when you initially installed your water heater.

Recovery Time Factors

Several factors affect how long it takes for your water heater to recover. These are the essential elements:

Fuel Source – Water may be heated more quickly with a gas water heater than with an electric one. 

Tank Size – Smaller tanks heat up more quickly since there is less water to warm. You should know that your water heater is replenishing while you shower since you can draw more hot water from a bigger tank. For water heaters, proper sizing is essential. You can be sure you’ll have hot water on demand by getting an appropriate tank for your household’s hot water requirements.

BTU Rating – An electric water heater can heat water more slowly than a gas water heater, resulting in quicker recovery.

Heating Element Wattage – Electric water heaters will quickly heat water with higher-wattage heating components.

First Hour Rating – Think about the heater’s First Hour Rating before purchasing. The performance and recovery of the heater are determined by this crucial statistic, which is frequently ignored. The First Hour Rating calculates the heater’s capacity in gallons per hour after assuming that the tank is initially full of hot water.

Age – Water heaters do not live indefinitely, and the unit’s age and condition will undoubtedly affect how quickly it recovers. Electric and gas water heaters both lose efficiency over time when heating water.


The time it takes to heat water with a typical 40-gallon heater is just around 30 to 40 minutes, while an 80-gallon tank would heat water in roughly 60 to 70 minutes. On the other hand, electric hot water tanks will take a bit longer. It will take 60 to 80 minutes for a typical 40-gallon electric heater and 2 hours for an 80-gallon tank.