Alpha Diverter Valve Seal Kit CD25X 3.018652

The Alpha 3.018652 Diverter Valve Seal Kit is a service kit of seals, O-rings and washers for the diverter valve assembly used across Alpha's CD-range combi boilers. The diverter valve switches the boiler between domestic hot water and central heating, and its internal seals are what keep the two circuits separated under pressure. Over time those seals harden, flatten or pick up scale, and the kit is the standard way to restore a leaking or passing valve rather than replacing the whole assembly.

• Water weeping or dripping from the diverter valve body or its spindle area
• Domestic hot water running warm or fluctuating while the heating is on
• Boiler losing pressure with no visible leak elsewhere on the system
• Radiators warming when only hot water is drawn, indicating the valve is passing
• Seals visibly hardened, swollen or coated in scale when the valve is stripped down

• Check the GC number and model on the boiler data badge against the compatibility list before ordering, as the CD range uses several similar valve builds.
• Confirm the part number on the existing component or in the boiler's service documentation matches 3.018652.
• If the diverter valve body or spindle is worn or scored, a seal kit alone may not restore a sound seal.
• This part is fitted to a gas appliance; installation must be carried out by a Gas Safe registered engineer.