Hot Water Recirculation: Is It Worth It in Australia?

Updated July 2026 · 6 min read · Geelong Emergency Plumbing

A hot water recirculation system solves a specific problem: the wait for hot water at a tap far from the hot water system. In a large house where the master bathroom is 20 metres of pipe away from the hot water unit, waiting 60–90 seconds for hot water while running the cold water to waste is an energy, water and time problem simultaneously. Recirculation is the engineering answer. Whether it makes economic sense for a specific property depends on four factors.

How Hot Water Recirculation Works

A recirculation system adds a return pipe from the furthest fixture back to the hot water system, with a small pump that continuously circulates hot water through the supply line. The water at every tap is always hot — or very close to it. When you open a tap, hot water is immediately available rather than waiting for the cold water in the supply line to be displaced.

Two variants exist:

Full recirculation (dedicated return line): a separate return pipe runs back to the hot water unit, forming a loop. Requires a dedicated return pipe, which is straightforward in a new build or major renovation where walls are open, and disruptive to retrofit in a finished building. The pump runs either continuously or on a timer and thermostat.

Comfort system (no return line): uses the cold water pipe as the return path. A pump at the furthest fixture circulates water back to the hot water unit through the cold line until the hot water reaches the pump's thermostat temperature, then shuts off. Easier to retrofit (no new pipe run), but means the cold water at that tap is temporarily warm — relevant for drinking water taps.

The Running Cost Calculation

This is where Australian context matters. A continuously running recirculation pump keeps the hot water supply line at temperature — which means the hot water system works harder to maintain the line temperature in addition to the stored tank. Studies on recirculation systems in Australian conditions consistently find that energy use increases, sometimes substantially, with a continuously running system.

On-demand systems (triggered by a button at the tap or by occupancy sensor) recirculate only when hot water is about to be used — eliminating the standby energy cost at the expense of a brief wait (typically 10–20 seconds for the pump to run and hot water to reach the fixture, versus the 60–90 seconds without recirculation). This is the configuration that makes the most sense in Australian energy-cost conditions: on-demand reduces water waste, reduces wait time, and doesn't impose significant ongoing energy cost.

Water Saving vs Energy Cost: The Real Trade-Off

The case for recirculation in Australia is primarily water conservation rather than time saving. Water costs in Geelong run approximately $1.50–$2.00/kL. A household discarding 10 litres every morning waiting for hot water saves $5–$7/year per tap. Against the pump's running cost and installation, pure water-saving economics only work in households with many taps and very long pipe runs. Where the case is stronger: households that pay a premium for water (tank water, elevated-tier billing), properties in active water restrictions, and households where convenience genuinely alters shower behaviour (people who shower shorter because hot water arrives faster).

Installation Cost

A comfort-system retrofit (no new pipe, pump at the furthest fixture): $400–$800 installed. A full recirculation loop in a new build or open-wall renovation: marginal cost when pipes are already being run. Retrofit of a full loop in a finished house: $1,500–$4,000 depending on the pipe run length and access. For most Australian homes, the comfort-system retrofit with an on-demand timer is the most practical entry point.

Alternatives Worth Considering First

Before installing recirculation, consider whether insulating the hot water supply pipe reduces wait time acceptably. A well-insulated pipe retains heat between uses and reduces the wait time significantly without any pump. In moderate climates like Geelong's, a pipe run of 10–15 metres with proper insulation can deliver hot water in 20–30 seconds rather than 90 — a meaningful improvement at a fraction of the cost and complexity of a recirculation system.

One less-discussed option that suits Australian climate conditions particularly well: a timer-controlled recirculation system set to run only during the household's peak morning and evening use windows rather than continuously or purely on-demand. The morning shower window is typically 30–60 minutes; the evening dishwashing and bathing window is similar. Running the pump only during these periods provides near-instant hot water when it is most needed while limiting the standby energy cost to two brief daily periods. This configuration sits between continuous and pure on-demand in both convenience and energy cost, and it is programmable on most modern recirculation pumps without additional hardware.

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Related guides: Hot water system cost guide · Heat pump hot water guide · Hot water repairs Geelong