Households and facilities waste thousands of liters of water and energy annually waiting for shower water to warm—while enduring cold-water delay. Heau’s Therm‑eau valve delivers instant hot water, eliminating waste and improving comfort.

Therm‑eau is Heau’s patented hydraulic valve technology, seamlessly integrated into shower fixtures (e.g., Therm‑eau fix, Integra, Expo, Box), designed for instant hot water from the first drop . Utilizing a mechanical membrane that captures residual heat from the previous shower, it redirects initial cold water into a storage chamber, pushing preheated water out until the boiler supplies full heat—completed entirely through water pressure, without electricity. This mechanism remains effective even days later, eliminating the 30°C cold-water flush usually experienced when starting a shower.

Compatible with any standard bathroom plumbing, it installs easily and blends with various faucet finishes, offering long-term durability certified by BELGAQUA.  

The premium feel, sleek design, and eco-conscious functionality have earned recognition with iF and ZVSHK awards  Therm‑eau enhances user comfort immediately and supports sustainable living by cutting water and energy waste—saving approximately 4,000 L of water and 110 kWh annually per household. Ideal for residential, hospitality, healthcare, or commercial buildings, Therm‑eau advances resource efficiency without sacrificing convenience.

Key characteristics:

• Patented hydraulic Therm‑eau valve; stores heat without electricity

• Effective up to 3 days after previous use; reset through regular showers 

• Integrates easily with any finish; modular internal components 

• Certified by BELGAQUA for water safety 

• Fits common wall thread (½″) and water pressure (2–6 bar) standards

• Durable mechanical design with accessible maintenance

Environmental benefits:

• Eliminates 40–60 seconds of cold water flush per shower, saving ≈4,000 L water/year

• Reduces 110 kWh energy use annually per home by avoiding reheating wasted water

• Zero-energy technology supports SDG 6/7/11/12 goals 

• Promotes user comfort—encourages widespread adoption of eco-friendly technology

• Extends lifespan of plumbing with less strain from fluctuating water temperature

Heau BV is a Belgian cleantech startup founded in 2022 by civil engineers Philippe Bijnens and Alexander Gowie, headquartered in Bilzen, Flanders heau.be +6 solarimpulse.com +6 be.linkedin.com +6 . They developed the patented Therm‑eau technology—a smart, mechanical valve system integrated into shower taps that stores residual heat from a previous shower, delivering instant hot water when next used, without any electricity solarimpulse.com +4 heau.be +4 heau.be +4 . This innovation reduces water and energy waste, enhances user comfort, and contributes to sustainable living. Heau’s taps are compatible with standard finishes, easy to install, and effective even when used days apart startupsmagazine.co.uk . The company emphasizes comfort and sustainability equally, designing premium yet durable products certified by BELGAQUA and recognized with the iF Design Award and ZVSHK “Comfort for All Generations” prize