Genuine OEM Lochinvar MSC3403 Bypass Assembly (100163257)

This is an Genuine OEM Lochinvar Bypass Assembly used in EnergyRite (model ERN/ERL) pool & spa heaters, which acts as a mechanical water flow regulator by regulating water flow to maintain proper internal operating performance and safety.

• p/n: MSC3403, 100163257
• Connection Size: 1/2″ NPT
• Calibrated Stainless Steel Spring: The core internal component is a high-tensile stainless steel spring designed to withstand constant immersion in chemically treated pool water without relaxing its tension or rusting.
• Plunger Material: Made of a glass-reinforced, high-temperature composite material that will not warp or deform under extreme heat or constant high-velocity friction.
• Seal Architecture: Outfitted with dual high-temperature EPDM rubber gaskets/O-rings designed to maintain a watertight hydraulic barrier under thermal fluctuations.
• Pressure-Differential Activation (Delta P): It is a mechanical, pressure-sensitive bypass. Rather than relying on electronics, it relies on hydraulic backpressure. When GPM (gallons per minute) from your pool pump spikes, the internal spring compresses to crack open the bypass lane
• Thermal Regulation Limits: Specially rated to maintain a target internal water temperature inside the copper heat exchanger tubes. It forces enough water restriction to keep the heat exchanger above the condensation “sweat” threshold (typically around 110°F to 115°F) while handling a maximum ambient water throughput.
• Flow Capacity: Internally bored to allow a dynamic high-volume bypass path, protecting the exchanger from the excessive flow velocities typical of 1.5 HP to 3.0 HP modern pool pumps.