boilingwatertap.

Model vs model

Grohe Red Duo L-Size
vs Qettle Signature

The Qettle Signature lists at £795, £830 less than the Grohe Red Duo L-Size at £1,625.

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 →
Qettle Signature Modern 4-in-1 boiling water tap

Qettle

Qettle Signature

Compact 4-in-1 for smaller kitchens

Typical price: £795

Full review →

The differences at a glance

  • The Qettle Signature lists at £795, £830 less than the Grohe Red Duo L-Size at £1,625.
  • The Qettle Signature dispenses at 100°C; the Grohe Red Duo L-Size tops out at 99°C.
  • Tank capacity: 5.5 L on the Grohe Red Duo L-Size versus 2 L on the Qettle Signature. Bigger tanks serve more cups back to back; smaller tanks take less cupboard space.

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 Qettle Signature specifications from manufacturer datasheets
SpecGrohe Red Duo L-SizeQettle Signature
Typical price£1,625£795
Boiling temperature99°C100°C
Tank capacity5.5 L2 L
Idle power-11 W
Peak power2100 W1300 W
Flow rate--
Filtered waterYesYes
Sparkling waterNoNo
Chilled waterNoNo
Filter typeBWT active carbonQ08 extruded carbon block cartridge
Finishes23
Warranty2 years2 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

Qettle Signature

What we like

  • Compact 2L tank fits tighter under-sink cabinets
  • Hits 100°C boiling matching premium-brand temperatures
  • £795 entry into Qettle's marine-grade Signature line
  • Trustpilot reviewers cite responsive UK customer service

Watch out for

  • 2L tank delivers only 4 mugs per fill in practice
  • Some users note aggressive water release on dispense
  • Handle can slip into filter mode accidentally
  • Same 2-year warranty inherits Original reliability concerns