Model vs model
Arno Square 4-in-1
vs Grohe Red Duo L-Size
The Arno Square 4-in-1 lists at £499, £1,126 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 →The differences at a glance
- The Arno Square 4-in-1 lists at £499, £1,126 less than the Grohe Red Duo L-Size at £1,625.
- The Grohe Red Duo L-Size dispenses at 99°C; the Arno Square 4-in-1 tops out at 98°C.
- Tank capacity: 5.5 L on the Grohe Red Duo L-Size versus 2.4 L on the Arno Square 4-in-1. Bigger tanks serve more cups back to back; smaller tanks take less cupboard space.
- The Arno Square 4-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.
| Spec | Arno Square 4-in-1 | Grohe Red Duo L-Size |
|---|---|---|
| Typical price | £499✓ | £1,625 |
| Boiling temperature | 98°C | 99°C✓ |
| Tank capacity | 2.4 L | 5.5 L |
| Idle power | 11 W | - |
| Peak power | 1500 W | 2100 W |
| Flow rate | - | - |
| Filtered water | Yes | Yes |
| Sparkling water | No | No |
| Chilled water | No | No |
| Filter type | 2-stage filter: PP cotton + activated carbon block | BWT active carbon |
| Finishes | 4✓ | 2 |
| Warranty | 3 years✓ | 2 years |
| Released | 2023 | - |
Strengths and trade-offs
Arno Square 4-in-1
What we like
- £499 RRP delivers 4-in-1 cheaper than most rivals
- 2-stage filtration removes chlorine and heavy metals
- 360° swivel spout handles pot-filling and rinsing
- Child-safe spring-loaded boiling dispense as standard
Watch out for
- 98°C ceiling not true 100°C boiling
- 2.4L tank yields only 7-8 cups before recovery
- Limited independent reviews outside Arno marketing
- Newer brand lacks long-term UK reliability track record
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