Ariston 65154089 O-Ring D=15.5 D=2.45

The Ariston 65154089 is a circular sealing O-ring with an outer diameter of 15.5mm and a cross-section of 2.45mm. It sits between two mating faces inside an Ariston heating appliance, compressing to form a watertight barrier at a joint, port or threaded connection. Seals of this type are used throughout the hydraulic circuit, where a small amount of water loss at a joint can quickly lead to pressure drop, corrosion or component damage.

• Water weeping or dripping from a joint, port or connection where the ring is fitted
• A visible trail of water staining, limescale or corrosion around the sealing face
• The ring feels hard, flattened or brittle rather than soft and pliable
• Cracks, nicks or a flattened cross-section visible when the ring is removed
• Repeated pressure loss or the appliance needing frequent topping up

• Confirm the part number 65154089 against your appliance's parts list or the label on the unit
• Measure the old ring before ordering, checking both the outer diameter and the cross-section against the figures above
• Note the alternative number 1593166 when cross-referencing suppliers or older documentation
• Inspect the mating faces and any adjacent seals while the joint is open, as scale or scoring can damage a new ring on reassembly