Plumber Wellington: What’s the Difference Between a Continuous Flow Water Heater and a Hot Water Cylinder?

Plumber Wellington: What’s the Difference Between a Continuous Flow Water Heater and a Hot Water Cylinder?

What Is a Hot Water Cylinder?

A hot water cylinder is a storage-based water heating system commonly used in New Zealand homes. This system stores a fixed amount of hot water—typically between 100 and 300+ litres—in an insulated tank. The water is heated using electricity, gas, or a wetback system, and remains stored until needed. As hot water is used, cold water refills the cylinder, which then needs time to reheat before more hot water becomes available.

Hot water cylinders are ideal for homes with consistent hot water usage or multiple bathrooms, as they can deliver hot water to several outlets simultaneously. However, once the hot water runs out, users may have to wait for the system to reheat the stored water.

What Is a Continuous Flow Water Heater?

A continuous flow water heater, also known as an instantaneous or tankless water heater, heats water on demand. When a hot water tap is turned on, cold water flows through the unit and is instantly heated by a gas burner or electric element. This method delivers an unlimited supply of hot water—as long as the unit’s flow capacity is not exceeded.

Continuous flow systems do not store water, which means they are more compact and energy-efficient, especially for smaller households or properties with limited space. These systems are perfect for people who want a modern, space-saving solution without worrying about running out of hot water.

Key Differences Between Continuous Flow and Hot Water Cylinders

• Energy Efficiency: Continuous flow systems heat water only when it is needed, reducing energy waste. In contrast, hot water cylinders may lose heat over time, even with good insulation.
• Hot Water Availability: Hot water cylinders offer a set volume of stored hot water, which can be depleted. Continuous flow systems deliver hot water endlessly, depending on flow rate capacity.
• Space Requirements: A hot water cylinder requires a dedicated area for the tank and piping. A continuous flow water heater is more compact and can often be wall-mounted, making it suitable for smaller homes or apartments.
• Installation and Maintenance: Hot water cylinders may require more extensive plumbing and space, while continuous flow units offer easier installation and often simpler maintenance over time.
• Flow Rate: Continuous flow heaters have a limited flow capacity, which might not meet the demand if multiple outlets are used simultaneously. Cylinders, on the other hand, can supply multiple taps at once, depending on their size and pressure.

Which System Is Right for You?

Choosing between a continuous flow water heater and a hot water cylinder depends on your household size, daily water usage, available space, and energy goals.

• If you prefer uninterrupted hot water and want to save on energy costs, a continuous flow system might be the right choice.
• If your household has high simultaneous hot water demands or prefers traditional setups, a hot water cylinder may be more suitable.

At Laser Plumbing Wellington East, we can help assess your property and recommend the most efficient and practical solution. Whether you need a new installation or a system upgrade, our experienced team is here to ensure you get the hot water system that best fits your needs.