As homeowners, we often take the convenience of hot water for granted. Whether it’s for a refreshing shower, a relaxing bath, or simply washing dishes, a reliable water heater ensures we have access to hot water whenever we need it. 

So, how long does a water heater take to heat up? 

In this comprehensive guide, we’ll discuss further about water heater heating times and answer common queries regarding heating durations. Keep reading below.

What is a Water Heater?

A hot water heater is a household appliance designed to heat water for domestic use, typically for bathing, cooking, cleaning, and space heating.

Most water heaters operate by utilizing a heat source, commonly electricity, natural gas, propane, or solar energy, to raise the temperature of the water stored in a tank. The most common types are storage tank heaters and tankless water heaters, each with its own set of advantages and considerations.

[Related: How Long Does It Take To Install a Water Heater?]

How Long Does a Water Heater Take to Heat Up?

The duration it takes for a water heater to heat up can vary depending on several factors, including the type of water heater, its size, the temperature setting, and the initial temperature of the water. 

In general, conventional tank-style water heaters typically take anywhere from 30 minutes to an hour to heat up the water inside the tank to the desired temperature.

For an electric hot water heater, the heating process begins once the thermostat detects that the water temperature has dropped below the set point. The heating elements then activates, and the water gradually heats up until it reaches the desired temperature.

Gas water heaters, on the other hand, utilize a burner located at the bottom of the tank to heat the water. When the thermostat signals a need for heating, the burner ignites, and the combustion process generates heat that warms the water.

Factors Affecting Heating Times

factors affecting heating time of water heater

Several factors can influence how long it takes for a water heater to heat up:

Type of Water Heater

Different types of water heaters, such as electric, gas, tankless, or solar-powered, have varying heating mechanisms and efficiencies, which can affect heating times.

A tankless water heater, for instance, provide hot water on demand and typically have shorter wait times compared to storage tank heaters, which need time to heat up a reservoir of water.

Size of the Water Heater

The size and capacity of the water heater, usually measured in gallons, determines the volume of water it can heat and store. Larger capacity water heaters may take longer to heat up compared to smaller ones.

Temperature Setting

The temperature setting on the water heater thermostat dictates how hot the water will be heated. Higher temperature settings may require more time to reach and maintain, whereas lower settings may heat up quicker but provide cooler water.

Initial Water Temperature

The starting temperature of the water entering the water heater can influence heating times. In colder climates or during winter months, the incoming water temperature may be lower, necessitating more time to heat it to the desired level.

Efficiency and Condition of the Heater

Well-maintained and efficient hot water heaters tend to heat water more quickly than those that are outdated or in need of repair. Sediment buildup in tank heaters can also impede heating efficiency, prolonging heat-up times.


The level of insulation in the water heater tank affects heat retention. Well-insulated tanks lose less heat to the surroundings, resulting in faster heating times.

Common Queries: Answered

Now, let’s address some common questions regarding water heater heating times:

How long does it take for water to heat up in a 50-gallon water heater?

On average, a 50-gallon water heater can take approximately 1 hour to 1 hour and 30 minutes to heat up from its initial temperature to the set temperature, depending on factors such as initial water temperature and heater efficiency.

water heater

How long does it take for hot water to come back in the shower?

In most cases, it can take anywhere from a few seconds to a few minutes for hot water to reach the shower after turning on the faucet.

This largely depends on the distance between the water heater and the shower, the type of piping system, and whether a recirculation system is installed. 

How long for the water heater to heat up after lighting the pilot light?

After lighting the pilot light on a gas water heater, it typically takes around 30 minutes to 1 hour for the water heater to heat up the water to the desired temperature, allowing for ample time for the burner to heat the water in the tank.

Seek Assistance From a Professional Plumber

By considering the type, size, settings, and initial temperature of the water, homeowners can optimize the hot water heater’s performance and ensure a reliable hot water supply for their daily needs. 

Remember, for any issues or concerns regarding your water heater, it’s always best to consult a professional plumber for expert advice and assistance.
If you’re in Prescott, AZ, and need reliable plumbing services, don’t hesitate to reach out to Stellar Plumbing. Our team of experienced plumbers is dedicated to providing top-notch service and ensuring your plumbing systems are in excellent working condition. Contact us today for all your plumbing needs!