Model vs model
Grohe Red Duo L-Size
vs InSinkErator 3N1 J-Shape
The InSinkErator 3N1 J-Shape lists at £899, £726 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 →
InSinkErator
InSinkErator 3N1 J-Shape
Steaming hot, hot and cold from a slim J-shape spout
Typical price: £899
Full review →The differences at a glance
- The InSinkErator 3N1 J-Shape lists at £899, £726 less than the Grohe Red Duo L-Size at £1,625.
- The Grohe Red Duo L-Size dispenses at 99°C; the InSinkErator 3N1 J-Shape tops out at 98°C.
- Tank capacity: 5.5 L on the Grohe Red Duo L-Size versus 2.5 L on the InSinkErator 3N1 J-Shape. Bigger tanks serve more cups back to back; smaller tanks take less cupboard space.
- The InSinkErator 3N1 J-Shape ships with a 5-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.
| Spec | Grohe Red Duo L-Size | InSinkErator 3N1 J-Shape |
|---|---|---|
| Typical price | £1,625 | £899✓ |
| Boiling temperature | 99°C✓ | 98°C |
| Tank capacity | 5.5 L | 2.5 L |
| Idle power | - | 11 W |
| Peak power | 2100 W | 1300 W |
| Flow rate | - | - |
| Filtered water | Yes | Yes |
| Sparkling water | No | No |
| Chilled water | No | No |
| Filter type | BWT active carbon | - |
| Finishes | 2 | 2 |
| Warranty | 2 years | 5 years✓ |
| Released | - | 2020 |
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