O-ring 2.5" Flat O-ring/Gasket

The 2.5" Flat O-ring Gasket is the larger-diameter flat-profile rubber gasket used at the pump-union intake on higher-flow Arctic Spas pumps. Like all flat gaskets, it sits between two flat union faces and seals by compression rather than seating into a groove.

Why pump intake gaskets fail: The intake side of a spa pump runs under suction, not pressure. That means a worn intake gasket may not drip when the spa is off (no positive water pressure pushing through the seal), but during operation the pump will pull air in past the gasket — which kills pump prime, makes the jets sputter, and in bad cases overheats the pump from running dry. The diagnostic is bubbly, inconsistent jet performance even when the spa is full and otherwise healthy.

When to replace: Any time you notice sputtery jet performance you can't otherwise explain, when you're disconnecting the pump for service, or when the existing gasket shows visible flat-spotting or hardening.

How to install: Drain the spa below the pump union first. Disconnect the union, remove the old gasket, clean both mating faces with a paper towel, and seat the new gasket flat. Hand-tighten the union — never use a wrench on a plastic spa union.

Quick tips:

• If your pump uses 2" fittings rather than 2.5", you need the 2" Flat O-ring Gasket instead
• Replace the matching pump-union O-ring at the same time — they age at the same rate
• Bring the old gasket to one of our three Ontario showrooms if you're not sure which size fits your pump