Australian Made and Owned
Why 65°C Hot-Water Loops May Be the Wrong Answer to Electrification
Many engineers are defaulting to >65°C loops post gas-to-electric conversion simply because that’s how it’s always been done for thermal Legionella control — without re-examining whether thermal disinfection is still the right strategy once the heat source changes.
The hidden cost: Heat pump COP degrades sharply as target temperature rises; running a loop at 65°C+ instead of 45°C can multiply electrical demand for hot water, partially or fully cancelling the emissions/cost benefit of switching off gas.
The alternative: Australian health guidance (enHealth Guidelines for Legionella Control, ABCB Handbook – Warm Water Systems (2020)) recognises continuous supplementary chlorination — not just elevated temperature — as a valid control strategy for warm water systems, provided it’s documented in the building’s Water Management Program.
eBooster™ dual disinfection treatment (including HOCl production) allows maintaining a continuous free-chlorine residual (typically in the 0.5–1.0 mg/L range, subject to the specific WMP and jurisdiction) at 43–45°C, where chlorine remains stable and effective.
That’s what makes the warm-loop approach viable: it doesn’t need the 65°C+ target at all.
Heat pumps provide efficient heat. Solar provides renewable energy. eBooster™ provides continuous microbiological protection.
Together they deliver safe, low-carbon hot water – so you can run cooler, cut carbon and cost, and stay compliant.