Autotrol Manifold/Piping Boss Replacement O Ring and Screw Pack

This is Autotrol's replacement o-ring and screw pack for the manifold, or "piping boss", connection where the control valve base meets the bypass or pipework manifold. Over time the o-rings that seal this joint harden and lose their sealing ability, and the retaining screws can corrode or wear, leading to weeping or dripping at the base of the valve. This small parts pack gives you everything needed to reseal the joint without replacing the manifold itself, and is stocked by WrekinWater for servicing Autotrol control valves.

Technical specifications

Symptoms that mean you need this part

• Water is weeping or dripping from the joint where the valve meets the manifold or bypass
• The o-rings at the piping boss have visibly hardened, flattened or perished
• Retaining screws are corroded, rounded off or won't tighten down evenly
• You've noticed dampness under the valve base that isn't coming from the drain or overflow

Why it fails / why it matters

The piping boss is the point where the control valve's base connects to the manifold or bypass assembly, and this joint relies entirely on a set of o-rings compressed by retaining screws to stay watertight under mains pressure. Repeated thermal cycling and years in service cause the o-rings to lose elasticity, while the screws can corrode or back off slightly, and either fault shows up as a slow weep at the base of the valve that gets worse over time. Replacing the o-rings and screws as a set restores the seal without needing to replace the manifold or valve.

Why buy this from WrekinWater

WrekinWater has supplied genuine and genuine-spec Autotrol parts to installers and DIY customers for over 15 years from its Bettisfield, Shropshire base, and keeps small service parts like this in stock alongside the full Pentair Fleck, Autotrol, Clack and Kinetico ranges so a minor leak doesn't turn into extended downtime. The business has served more than 50,000 customers and is rated Excellent on Trustpilot.

How to fit it

1. Isolate the softener or filter at the bypass valve and relieve system pressure before starting
2. Undo the retaining screws holding the manifold to the valve base and separate the two carefully
3. Remove the old o-rings from the piping boss grooves and clean the mating faces of any scale or debris
4. Fit the new o-rings from this pack, lubricating lightly with silicone grease to ease reassembly
5. Refit the manifold to the valve base and secure evenly with the new screws supplied
6. Restore water supply and check the joint closely for leaks before leaving the system in service