The Pentair Water Bypass Assembly (475621) is the OEM replacement bypass assembly for the Pentair ETi® 400 Heater, restoring proper water flow regulation within the heater's internal plumbing circuit.
⚠️ IMPORTANT: LICENSED PROFESSIONAL INSTALLATION REQUIRED
Gas and electrical heater components must be serviced by a licensed pool professional or qualified HVAC technician. Do not attempt to service gas or high-voltage components without proper certification.
The water bypass assembly regulates the distribution of water flow through the ETi® 400 Heater's internal plumbing. When this assembly fails or degrades, the heater may experience uneven heat exchange, reduced efficiency, or flow-related fault conditions. Replacing it with the OEM Pentair unit restores the designed flow balance within the heater circuit.
Specifications
| Pentair Part Number |
475621 |
| Part Name |
Water Bypass Assembly |
| Quantity Included |
Each |
Fits Into
| Brand |
Equipment Line |
Model / Part Number |
Notes |
| Pentair |
ETi® 400 Heater — ETi Series |
ETi400 |
— |
Compatibility is based on Pentair parts documentation and available OEM records. This is not an exhaustive list. For certainty, verify the part number in your equipment's manual or on the original part itself before ordering.
Pro Tip
Before ordering, confirm the part number stamped or molded on your existing bypass assembly matches 475621. Have a licensed pool professional inspect the surrounding plumbing connections and O-rings while the heater is open — replacing worn seals at the same service visit prevents a return trip.
