boilingwatertap.

Model vs model

Grohe Red Duo L-Size
vs Zip HydroTap G5 Celsius Arc (3-in-1)

The Grohe Red Duo L-Size lists at £1,625, £446 less than the Zip HydroTap G5 Celsius Arc (3-in-1) at £2,071.

Every number below comes from the manufacturers' own specification sheets. We highlight which tap leads on each spec; what matters most for your kitchen is your call.

Grohe Red Duo boiling water tap with L-size boiler

Grohe

Grohe Red Duo L-Size

99°C filtered boiling water plus a full hot-and-cold mixer

Typical price: £1,625

Full review →
Zip HydroTap G5 Celsius Arc All-In-One chrome swan-neck tap

Zip Water

Zip HydroTap G5 Celsius Arc (3-in-1)

Arc spout for filtered boiling plus mains hot and cold

Typical price: £2,071

Full review →

The differences at a glance

  • The Grohe Red Duo L-Size lists at £1,625, £446 less than the Zip HydroTap G5 Celsius Arc (3-in-1) at £2,071.
  • The Grohe Red Duo L-Size dispenses at 99°C; the Zip HydroTap G5 Celsius Arc (3-in-1) tops out at 98°C.
  • Tank capacity: 5.5 L on the Grohe Red Duo L-Size versus 3 L on the Zip HydroTap G5 Celsius Arc (3-in-1). Bigger tanks serve more cups back to back; smaller tanks take less cupboard space.
  • The Zip HydroTap G5 Celsius Arc (3-in-1) ships with a 3-year warranty; the Grohe Red Duo L-Size with a 2-year warranty.

Full specification, side by side

Sourced from manufacturer datasheets. A tick marks the better number on specs where more or less is objectively better.

Grohe Red Duo L-Size vs Zip HydroTap G5 Celsius Arc (3-in-1) specifications from manufacturer datasheets
SpecGrohe Red Duo L-SizeZip HydroTap G5 Celsius Arc (3-in-1)
Typical price£1,625£2,071
Boiling temperature99°C98°C
Tank capacity5.5 L3 L
Idle power-30 W
Peak power2100 W2200 W
Flow rate-4 L/min
Filtered waterYesYes
Sparkling waterNoNo
Chilled waterNoNo
Filter typeBWT active carbonZip MicroPurity 0.2 micron filter
Finishes24
Warranty2 years3 years
Released-2023

Strengths and trade-offs

Grohe Red Duo L-Size

What we like

  • Boiling, filtered and a full hot-and-cold mixer in one tap, no second tap hole
  • Large 5.5L boiling reserve (7L total) on the L-size boiler
  • Child-safe touch-button dispensing with ChildLock as standard
  • Sells around £1,625 at UK specialists, far below the £2,578 list price

Watch out for

  • 99°C dispense, not a true 100°C boil (despite Grohe’s "100°C" marketing)
  • At around £1,625 it is still a premium tap, though far below its £2,578 list
  • BWT filter must be changed yearly or every ~600L, an ongoing cost
  • Standard guarantee is 2 years (3 only with registration), shorter than InSinkErator or Franke

Zip HydroTap G5 Celsius Arc (3-in-1)

What we like

  • 0.2-micron MicroPurity filter removes dirt, lead, microplastics and 99.9% of cysts
  • Cool-touch tap with boiling isolation and safety lock
  • Boiling flow of 4 litres per minute
  • Seven finishes and a 12-month filter interval

Watch out for

  • Factory-set to 98°C rather than true 100°C boiling
  • Needs both hot and cold supply at 1.7 bar minimum
  • Three-year warranty (five on the tank)