Tankless water heaters are becoming a popular choice in modern homes because they are efficient, compact, and designed to provide continuous hot water. However, homeowners often have questions about how they work, how much hot water they can provide at one time, and why hot water may still take time to reach certain taps.

To help answer these common questions, we partnered with our plumbing supplier, , to explain what homeowners should know about tankless water heaters and what to expect from their system.

What is a tankless water heater?

A tankless water heater heats water only when you need it. Unlike a traditional hot water tank, which stores a set amount of hot water, a tankless unit heats water as it flows through the system.

This means the system is not continuously heating a large tank of water throughout the day. Instead, it activates when hot water is needed and heats the water as it flows through the unit.

What are the benefits of a tankless water heater?

Tankless water heaters offer several benefits for homeowners.

First, they are efficient. Because they only heat water when it is needed, they can use energy more efficiently than a traditional hot water tank.

Second, they are compact. Tankless units are wall-mounted, which helps free up valuable space in the mechanical room.

Third, they provide continuous hot water. Unlike a traditional tank that can run out of stored hot water, a tankless system continues heating water as it flows through the unit.

Does tankless mean unlimited hot water?

One of the biggest benefits of a tankless water heater is continuous hot water. However, there are some important nuances to understand.

A tankless system can continue heating water as long as there is demand, but it still has a maximum capacity for how much hot water it can produce at one time. The system prioritizes water temperature over flow rate.

That means if multiple showers, taps, or appliances are using hot water at the same time, the system may reduce the flow slightly so it can maintain the proper water temperature.

Can a tankless water heater supply multiple fixtures at once?

Yes, a tankless water heater can supply multiple fixtures, but performance depends on how much hot water is being requested at the same time.

For example, if several showers, faucets, or appliances are all using hot water at once, the unit has to work harder to heat that larger volume of water. To keep the water hot, the system may slightly reduce the flow.

This does not mean the system is not working properly. It is part of how tankless water heaters maintain consistent water temperature.

Does Alberta’s winter weather affect tankless water heaters?

Yes, it can.

In Alberta, municipal water can be very cold during the winter. Because the incoming water is colder, the tankless unit needs to work harder to heat it to the desired temperature.

During colder months, the system may slow the flow slightly to give the water enough time to heat as it passes through the unit. This is normal and helps ensure the water reaches the right temperature.

Why does it take time for hot water to reach my tap?

This is one of the most common questions homeowners have.

A tankless water heater can take a few seconds to fire up if it has not been running for a while. This typically takes around 2 to 15 seconds. After that, the wait time is usually not much different than with a traditional hot water tank.

The biggest factor is the size and layout of the home. If a tap is far away from the water heater, the cold water sitting in the pipes needs to be pushed out before hot water arrives.

Is it normal to wait a few minutes for hot water?

In many cases, yes.

In Canada, a wait time under approximately 2 to 3 minutes is generally considered acceptable for hot water to reach a tap. In larger homes, especially when the water heater is located far from certain fixtures, a wait time of up to 3 minutes may still mean the system is functioning normally.

The wait time is usually related to the distance between the water heater and the tap, not necessarily the type of water heater.

Common misconception: Does tankless mean instant hot water?

No. This is one of the most common misconceptions about tankless water heaters.

Tankless means continuous hot water, not instant hot water at every tap. The water still needs to travel through the plumbing lines before it reaches the faucet, shower, or appliance.

If the tap is far from the water heater, it will still take time for the hot water to arrive.

Key takeaways for homeowners

Tankless water heaters are an efficient and space-saving option that can provide continuous hot water. However, it is important to understand how they work.

Here are the key points to remember:

• They are compact and wall-mounted, saving space in the mechanical room.
• They provide continuous hot water, but not instant hot water.
• They prioritize temperature over flow rate.
• If multiple fixtures are using hot water at once, flow may be reduced slightly.
• Alberta’s cold winter water can affect how hard the system needs to work.
• Hot water wait time is usually related to the distance between the water heater and the tap.
• A wait time of approximately 2 to 3 minutes can be normal in larger homes.

Final thoughts

Tankless water heaters are a great solution for many modern homes, especially for homeowners looking for efficiency, space savings, and continuous hot water. Like any home system, understanding how it works helps set the right expectations.