Model vs model
Grohe Red Duo L-Size
vs Qettle Signature Modern 4-in-1 (Round Spout, 7L)
The Qettle Signature Modern 4-in-1 (Round Spout, 7L) lists at £945, £680 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
Grohe Red Duo L-Size
99°C filtered boiling water plus a full hot-and-cold mixer
Typical price: £1,625
Full review →
Qettle
Qettle Signature Modern 4-in-1 (Round Spout, 7L)
Higher-capacity 7L boiler for larger households
Typical price: £945
Full review →The differences at a glance
- The Qettle Signature Modern 4-in-1 (Round Spout, 7L) lists at £945, £680 less than the Grohe Red Duo L-Size at £1,625.
- The Qettle Signature Modern 4-in-1 (Round Spout, 7L) dispenses at 100°C; the Grohe Red Duo L-Size tops out at 99°C.
- Tank capacity: 7 L on the Qettle Signature Modern 4-in-1 (Round Spout, 7L) versus 5.5 L on the Grohe Red Duo L-Size. 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.
| Spec | Grohe Red Duo L-Size | Qettle Signature Modern 4-in-1 (Round Spout, 7L) |
|---|---|---|
| Typical price | £1,625 | £945✓ |
| Boiling temperature | 99°C | 100°C✓ |
| Tank capacity | 5.5 L | 7 L |
| Idle power | - | 18 W |
| Peak power | 2100 W | 1700 W |
| Flow rate | - | - |
| Filtered water | Yes | Yes |
| Sparkling water | No | No |
| Chilled water | No | No |
| Filter type | BWT active carbon | Q08 extruded carbon block cartridge |
| Finishes | 2 | 5✓ |
| Warranty | 2 years | 2 years |
| Released | - | 2022 |
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 Modern 4-in-1 (Round Spout, 7L)
What we like
- 7-litre tank serves up to 14 cups in one go, sized for larger households
- Four separate waterways and no electronic components in the tap
- Two-stage child safety: button and turn before boiling water flows
- Marine-grade stainless steel tap, engineered in the UK
Watch out for
- 20-minute initial heat-up and 15-minute recovery after a full tank
- Two-year warranty
More comparisons with these taps
Grohe Red Duo L-Size vs...
Qettle Signature Modern 4-in-1 (Round Spout, 7L) vs...
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- Qettle Signature Modern 4-in-1 (Round Spout, 7L) vs Franke Minerva →
- Qettle Signature Modern 4-in-1 (Round Spout, 7L) vs Qettle Signature Modern 4-in-1 (4L) →
- Qettle Signature Modern 4-in-1 (Round Spout, 7L) vs Quooker Nordic Round Single Tap →