Continuous flow hot water systems — often called tankless or instantaneous systems — heat water on demand rather than storing it in a tank. They've become popular on the Gold Coast, but like any system type, they suit some households better than others. Here's an honest look at the benefits and the limitations.
1. Never run out of hot water
The biggest advantage of a continuous flow system is that it heats water as you use it, so there's no tank to empty. As long as the system can keep up with the flow rate, you can shower indefinitely. This suits households where the morning shower rush regularly empties a storage tank.
2. No standby heat loss
A storage tank loses heat through its walls continuously, which means the system reheats water even when nobody's using it. A continuous flow system only heats water when a tap is opened, so there's no standby heat loss. Over a year, this can reduce energy use — though the actual saving depends on your usage pattern and energy source.
3. Compact size
Continuous flow units are much smaller than storage tanks, which makes them suitable for homes with limited space. They're typically wall-mounted on an exterior wall, freeing up floor space that a tank would occupy.
4. Longer service life for the unit
Because continuous flow systems don't store water, they don't suffer from the sediment buildup and tank corrosion that shortens the life of storage systems. A well-maintained continuous flow unit can outlast a storage tank, though component repairs (like any system) may be needed over its life.
5. Precise temperature control
Most modern continuous flow systems deliver water at a set temperature with precise digital controls, eliminating the need for a tempering valve and reducing scalding risk. You set the temperature once and the system modulates the burner to maintain it.
6. Energy source options
Continuous flow systems are available in gas and electric models. Gas continuous flow is the most common on the Gold Coast, as gas provides the rapid heat input needed to heat water on demand. Electric continuous flow systems draw very high current and may require a significant electrical upgrade, so they're less common for whole-house use.
Limitations to consider
Continuous flow systems aren't automatically better for every household. Consider these limitations:
- Flow rate limits — a continuous flow system can only heat a certain volume of water per minute. If two showers run simultaneously, the flow to each may drop. Sizing by flow rate is critical — see our hot water sizing guide
- Higher upfront cost — continuous flow units typically cost more to purchase and install than a comparable storage system, particularly if a gas connection needs to be run.
- Gas supply required — for gas continuous flow, you need an adequate gas supply, which may require upgrading the gas line. See our gas fitting services
- Minimum flow to activate — most systems need a minimum flow rate to trigger the burner, which can mean a trickle of hot water isn't possible. This can be an issue for low-flow tasks like rinsing.
- No stored reserve — if the gas or power supply is interrupted, you have no hot water at all, whereas a storage tank holds a reserve.
Is a continuous flow system right for you?
Continuous flow systems suit households that regularly run out of stored hot water, have limited space, and want to eliminate standby heat loss. They're less ideal for households with very high simultaneous demand (multiple showers at once) or where a gas upgrade would be expensive.
The right choice depends on your usage, your existing plumbing and gas supply, and your budget. If you're considering a continuous flow system on the Gold Coast, contact our hot water team for tailored advice and installation.
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