Hassle-free delivery

Duties & taxes included. No surprises.

Warranty

Every product comes with dedicated warranty coverage.

Refer a friend

They get 10% off. You get 10% cashback.

Secure payment

Your payment details are always processed securely.
1 1

Hamwells

Blue 21XE

Blue 21XE

€1.629,00 EUR
€1.629,00 EUR
Sale Sold out
Taxes included. Shipping calculated at checkout.

Blue recovers heat from used shower water and puts it straight back to work. By transferring that energy to the incoming cold water, it reduces the energy needed for your shower without compromising on comfort.

Compact, reliable and easy to integrate, Blue 21XE can recover up to 70.6% of otherwise wasted heat, helping lower energy use, reduce CO₂ emissions and ease the demand on heating systems.
View full details
%

Energy efficiëncy

Recover energy that would otherwise disappear down the drain.

Robust design

Thoroughly tested and made from high-quality materials, the Blue is designed to require minimal maintenance.

Future proof

Built for the homes of tomorrow:
reduce your hot water-energy demand.

Lower Bills

Reuse shower heat and reduce your energy costs significantly.

about blue

Energy recovery


A subtle LED indicator shows when Blue is actively recovering heat from your shower water. Available in chrome, matte black and copper to match your bathroom.

Energy consumption

Curious what you could save?

Get an estimate of your yearly energy and cost savings, plus the potential reduction in CO₂ emissions.

Your household

Adjust your household and shower habits to estimate your annual energy, cost and CO₂ savings.

4
10 min
7 ×
/ kWh

Enter your current energy price in EUR per kWh.

Blue version

Your estimated savings*

Calculated from your household, shower habits and selected hot-water supply.

Estimated saving per year €0
Heat recovery Based on 8 L/min
0%
Energy saved / year
0 kWh
CO₂ reduction / year
0 kg

* This calculator provides an indicative estimate only, based on the information entered and standard assumptions. Actual energy, cost and CO₂ savings may vary depending on installation, usage, system performance and energy rates. Calculated results are not a guarantee of actual savings or performance.

View calculation method.

5.00 ★ (4)
Verified

about blue

Waste Water Heat Recovery explained

Blue recovers heat from used shower water before it disappears down the drain. That heat is used to preheat the incoming cold water, so less hot water, and therefore less energy, is needed to keep your shower at the right temperature.

The system works automatically in the background and is designed to handle everyday shower use. Clean water and wastewater always remain completely separate.

  • Shower Heat Recovery in a historic farmhouse

    Shower Heat Recovery in a historic farmhouse

    In Kekerdom, the historic Scholtenhof farmhouse has recently been transformed into a sustainable group accommodation for up to 24 guests. Dating back to the early 18th century, the property includes...

    Shower Heat Recovery in a historic farmhouse

    In Kekerdom, the historic Scholtenhof farmhouse has recently been transformed into a sustainable group accommodation for up to 24 guests. Dating back to the early 18th century, the property includes...

  • Hamwells x The Urban Woods

    Hamwells x The Urban Woods

    Blue at The Urban Woods Delft The Urban Woods was completed in Delft in June 2026. The residential building consists of 102 apartments across ten floors and is largely constructed...

    Hamwells x The Urban Woods

    Blue at The Urban Woods Delft The Urban Woods was completed in Delft in June 2026. The residential building consists of 102 apartments across ten floors and is largely constructed...

  • GROHE unveils Rapido Heat Recovery Shower System at ISH Frankfurt 2025

    GROHE unveils Rapido Heat Recovery Shower Syste...

    GROHE unveils Rapido Heat Recovery Shower System at ISH Frankfurt 2025 Innovative co-creation: GROHE uses latest sustainable shower technology developed by Hamwells for state of the art shower system Game-changing energy efficiency:...

    GROHE unveils Rapido Heat Recovery Shower Syste...

    GROHE unveils Rapido Heat Recovery Shower System at ISH Frankfurt 2025 Innovative co-creation: GROHE uses latest sustainable shower technology developed by Hamwells for state of the art shower system Game-changing energy efficiency:...

1 3

Specifications

Included

Blue Box

  • Pump unit with power supply and control electronics
  • 1,5 m power cable with bare ends
  • M12 connector for connecting Flow Sensor
  • Mounting Brackets for positioning Blue Box on the Heat Exchanger
  • 1,3 m pressure hose with clamp for Reservoir connection
  • 1,3 m pressure hose with clamp for Heat Exchanger connection

Waste Water Heat Exchanger

  • KIWA / WRAS certified 21XE Heat Exchanger
  • Mounting Brackets for positioning Heat Exchanger to your wall

Flowsensor

  • Flow sensor with capacity: 1 - 10 liter/min
  • Power/data: 2 m cable with M12 connector to Blue Box

Reservoir
Reservoir unit for pump

LED indicator

  • LED indicator for placement in shower
  • 3 m cable to Blue Box

Dimensions
30 x 16 x 210 cm / 11.8 × 6.3 × 82.7 in
Weight
13,5 kg / 29,8 lbs
Efficiency rate
70.6% - 8,0 L /min, measured according to NTA8800
Power supply
  • 100- 240 VAC input
  • 50 Hz - 60 Hz input
Maximum power draw
  • 48 W maximum continues power draw when pumping
  • <1 W standby power
Water capacity
14 Liter/minute maximum capacity
Connection requirements

Waste Water Heat Exchanger
• Cold water inlet: G1/2" female thread (bottom side)
• Cold water outlet (heated): G1/2" female thread (top side)
• Waste water outlet: 50mm (bottom side, to waste water mains)

Flow sensor
• Inlet: G1/2"male thread (from hot water supply)
• Outlet: G1/2"male thread (to bathroom mixing valve)

Reservoir
• 50mm inlet (from shower drain)
• 50mm outlet (to waste water mains)

Ready to ship in
3 - 4 weeks

Frequently asked questions

What is shower heat recovery?

Shower heat recovery captures heat from warm shower wastewater and transfers it to incoming cold water. This preheats the incoming water and reduces the amount of new energy required to produce hot shower water.

Does shower heat recovery reuse wastewater?

No. The wastewater is not reused as shower water. Only its heat is recovered.

Does the Blue need to remain accessible after installation?

Yes.

The Blue should remain sufficiently accessible for inspection, service, repair and replacement of components.

We strongly recommend checking the required access before permanently closing or finishing the surrounding wall, floor or other construction.

Can the Blue be connected to any hot water supply?

Because the Blue systems make use of the residual energy in the wastewater, it does not matter how the hot water is heated.

What happens if the power is switched off?

The Blue requires electrical power to operate. If the power supply is switched off or interrupted, the system will not operate until power is restored.

View all frequently asked questions