Waterway Heater Union Gasket O-Ring | 1 1/2" | 711-4050

The Waterway 711-4050 is a precision-manufactured O-ring gasket engineered for 1½″ heater union applications. Designed by Waterway in the U.S.A., this ribbed O-ring gasket ensures a secure, leak-free seal between heater tailpieces and union fittings. With an outside diameter of approximately 2-5/16″ and an inside diameter of about 1-7/16″, it delivers reliable compatibility for standard 1½″ unions. Crafted from durable elastomeric materials, it resists pool-and-spa chemicals, temperature fluctuations, and repeated service cycles. Whether you’re replacing a worn seal during routine maintenance or reinforcing your heater union to prevent future leaks, this gasket is an essential part of maintaining optimal pool or spa system performance.

Highlights

• Precise Fit Dimensions: Designed with an OD of ~2.31″ and ID of ~1.44″ to match standard 1½″ heater unions.

• Ribbed O-Ring Profile: Features a built-in ribbed sealing lip that enhances sealing engagement and helps prevent micro-leaks at the union interface.

• Chemical & Thermal Resistance: Manufactured for pool and spa use, it withstands exposure to sanitizers, heated water, and plumbing pressure changes.

• OEM-Quality Construction: Produced by Waterway to meet original equipment specifications for longevity and compatibility.

• Easy Replacement Upgrade: Slip in place during union re-assembly — an efficient, low-cost preventative maintenance measure to avoid costly leaks.

Additional Info

For customers ordering online, the OEM Waterway 711-4050 1½″ Heater Union Gasket O-Ring provides a dependable seal for heater and pump unions using 1½″ fittings. This guide covers compatibility checks, installation questions and how to maintain leak-free performance after your order arrives.

Confirming Fitment Before Ordering Online

This gasket fits 1½″ Waterway-style unions with approximate 1-5/8″ ID and 2-3/8″ OD dimensions. It replaces legacy part numbers including 711-4050B, 9175-41 and 90-423-1002, making it suitable for a wide range of heaters and plumbing assemblies.

How to confirm online that my heater union uses the 711-4050 gasket

Whether this gasket fits both Waterway and compatible after-market unions

Can I order multiple gaskets together for free shipping

What measurements I should verify before placing an order

Whether this gasket fits both pump unions and heater unions

Installing the Gasket After Delivery

Once delivered, the gasket must be aligned squarely within the union groove, ensuring that the ribbed O-ring edge contacts the sealing surface. Tightening the union evenly prevents misalignment and leakage.

How to install the gasket correctly to avoid drips after startup

Whether lubricant helps seat the ribbed Waterway gasket properly

What to do if the union still leaks after installing a new gasket

How to check the tailpiece for warping after heater cycles

Whether I can order matching tailpieces online if mine is damaged

Keeping Heater and Pump Connections Leak-Free

A properly installed union gasket prevents water loss, pressure drops and premature heater wear. Replacing worn gaskets ensures stable system performance and helps keep water clean and balanced.

Why union gaskets wear out faster on high-heat spa systems

How often to reorder 1½″ Waterway union gaskets online

Whether this part qualifies for fast or free shipping with additional items

How to detect tiny weeping leaks before they become major failures

Are bundled union repair kits available that include this gasket