Arno Square 4-in-1

The Arno Square is the most directly value-aggressive 4-in-1 on this list at £499, matching the Qettle Original on price, with boiling, filtered, and mains hot-and-cold water from one tap. The Square refers to the geometric spout silhouette, and the tap is controlled via a digital touchscreen rather than the more traditional push-and-turn levers used by Quooker and Franke.

The standout is the price. A 4-in-1 with a 2-stage carbon filter for £499 undercuts almost everything with the same function set. The boiling temperature reaches 98°C, which is enough for tea, coffee, and most cooking even if not a true 100°C, and the cool-touch spout and spring-loaded safety lock are competent rather than cut-price.

Brand maturity and the touchscreen itself are the open questions. Trustpilot reviews are visibly more split than the established players: positive on the install experience and the safety features, mixed on the touchscreen needing several presses before the boil symbol responds, and consistently critical of customer service when something does go wrong. The touchscreen control unit is also an extra failure point that an Arno-grade brand has less of a service network to support if it goes wrong. A genuinely cheap 4-in-1, with the risk that you may be on your own in year three.