How Long Does a Hot Water System Take To Heat Up

Whether you’re waiting for your morning boost or a relaxing evening soak, knowing how long your hot water system takes to heat up can save time, energy, and frustration. Let’s break down what affects heat-up times and how you can get hot water faster.

Hot water isn’t just a luxury—it’s a daily essential.

Whether it’s for a warm morning shower, sparkling clean dishes at home, or efficient laundry services in a hotel, hot water powers comfort and hygiene across both homes and businesses.

From solar-powered systems to gas and electric options, hot water systems are built to deliver heating and store water on demand.

In Australia, they’ve become a trusted solution, keeping households and commercial spaces running smoothly every single day.

However, do you know how long it takes for your hot water system to heat up?

We will explore some of the different types of hot water systems and determine how long it takes each one to heat up. Factors influencing heat time will also be discussed.

The different types of hot water systems and the time it takes to heat up.

1. Heat-up time: Electric hot water systems

There are two varieties of electric hot water systems: one type has a storage tank, while the other is tankless. 

Electric water systems with a storage tank store a large amount of water that can be used for multiple purposes, such as running showers.

There is an element within the tanks that facilitates the heating process, just like in an electric kettle. Water in the electric hot water system is insulated and requires periodic reheating to maintain the set temperature.

The second tankless option (the continuous flow hot water system) can heat water to the desired temperature when there is demand for it, without the need to store the water.

High-powered heating elements are used for heating, requiring up to 3-phase power to be connected. 

The wait for more hot water in the electric tank system can be longer, whereas for the tankless system, it will depend on how far the pipes are from the outlet.

The tankless system is said to heat up water within a few minutes (5-7 minutes, for instance), where water is transferred to the heating elements, which send it directly to the shower. 

The electric hot water systems with a tank need 1-2 hours to heat a 150-litre tank. The type of water heater determines heating time, with propane tankless taking 0 minutes.

2. Heat-up time: Gas hot water system

This type of heater also comes in two varieties: the gas hot water storage system and the continuous flow water system. A gas burner located underneath the storage tank is used to heat the stored hot water continuously. For safety reasons, the water is maintained at 60 °C.

The continuous flow type is fueled by gas, ensuring no heat is lost during the process. Hot water is delivered continuously, hence this type requires considerations of sized gas pipes and gas meters. 

The time it takes for the gas hot water storage system to heat water will vary.

However, under normal circumstances, it will take 30-60 minutes for a 150-litre tank. For the other type, no time is needed as hot water flows instantly once the tap is turned on. 

3. Heat-up time: Solar hot water system

Solar hot water systems have existed since the early 1980s and are installed in a good number of homes.

Due to the dependency on solar energy, there are times when solar supply is in excess and times when it is deficient. The domestic solar hot water system is able to receive controlled signals based on the environmental temperatures.

This system allows one to use energy stored at any preferred time based on need, i.e. collect and store the solar energy on a given day to use it on a later date. 

Solar energy heaters depend on several variables for the time it takes to heat water.

These include the availability of sunlight on a particular day, the capacity of the storage tank, and the initial temperatures of the water.

Expect a few hours (at least half a day) to heat water on a sunny day and a bit longer (at least the whole day) for the same on a cloudy day. 

4. Heat-up time: Heat-pump hot water system

Heat is extracted from the ambient air and then transferred to the water in this type of hot water system. The heating is almost like the electric type. However, heat pumps have a better heating rate. 

The water heating time using a heat pump will also depend on various factors like ambient air temperature around the heat pump’s air heat exchanger and the power that the heat transfer can transfer into the water.

A 250-litre tank filled with completely cold water may take approximately 3-3.5 hours to heat the water, assuming the water heater is set at 60 Degrees Celsius. 1 to 2 hours will be required for a 150-litre tank of water to heat.

Factors That Affect Heat-up Time

Many factors influence the time it takes to heat water using the different hot water systems. Some factors only affect specific types of systems.

For instance, the availability of sunshine and the geographical location of the user are the only factors determining heating time for solar hot water systems. A summary of common factors affecting all systems includes:

• The size of the storage equipment 
• The initial water temperatures and the water temperature settings for heating are limited.
• The efficiency of the heating element, e.g. a burner in the gas hot water system. 
• System efficiency and age.

Control and Maintenance of Hot Water Systems for Better heat-up Time

The performance of the hot water system in use will contribute to better heating time.

Consider regular evaluation of the system, like ensuring thermostat settings are working well, no water is leaking, and the heating elements are in good working condition.

When purchasing, consider the best hot water system that suits your needs and environment. Regular maintenance is recommended for maintaining consistent or improved heat-up time.

Conclusion

Every user needs to know the time it takes to heat water, at least for the hot water system they use.

The factors that influence heat-up time require much consideration to allow you to save energy and achieve optimal performance with your hot water system. You may need to consult a professional for expert services.