The Pentair Water Pressure Switch (42001-0060S) is the OEM replacement pressure switch for the MasterTemp, Max-E-Therm, and ETi series pool and spa heaters. This single-component switch monitors water flow through the heater's water system and is a direct-fit replacement for the original Pentair part. ⚠️ 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 pressure switch signals the heater's control system that adequate water flow is present before allowing ignition. When this switch fails or gives a false reading, the heater will refuse to fire — protecting the heat exchanger from dry-fire damage. A faulty switch is a common cause of heater lockout and no-heat faults on MasterTemp and Max-E-Therm units. Replacing this switch restores normal ignition sequencing when the switch itself has been confirmed as the fault. Specifications Pentair Part Number 42001-0060S Part Name Water Pressure Switch Quantity Included 1 (Each) Fits Into Brand Equipment Line Model / Part Number Notes Pentair MasterTemp Series MASTERTEMP 125 Not included in Manifold Kit (Item 2) Pentair MasterTemp Series 175NA Water Pressure Switch; applies to MasterTemp water system parts section. Verify fitment before ordering. Pentair MasterTemp Series 175LP Water Pressure Switch; applies to MasterTemp water system parts section. Verify fitment before ordering. Pentair MasterTemp Series 200NA Water Pressure Switch; applies to MasterTemp water system parts section. Verify fitment before ordering. Pentair MasterTemp Series 200LP Water Pressure Switch; applies to MasterTemp water system parts section. Verify fitment before ordering. Pentair MasterTemp Series 250NA Water Pressure Switch; applies to MasterTemp water system parts section. Verify fitment before ordering. Pentair MasterTemp Series 250LP Water Pressure Switch; applies to MasterTemp water system parts section. Verify fitment before ordering. Pentair MasterTemp Series 300NA Water Pressure Switch; applies to MasterTemp water system parts section. Verify fitment before ordering. Pentair MasterTemp Series 300LP Water Pressure Switch; applies to MasterTemp water system parts section. Verify fitment before ordering. Pentair MasterTemp Series 400NA Water Pressure Switch; applies to MasterTemp water system parts section. Verify fitment before ordering. Pentair MasterTemp Series 400LP Water Pressure Switch; applies to MasterTemp water system parts section. Verify fitment before ordering. Pentair Max-E-Therm Series MAX-E-THERM-200-NA Water Pressure Switch for Max-E-Therm heaters. Pentair Max-E-Therm Series MAX-E-THERM-333-NA Water Pressure Switch for Max-E-Therm heaters. Pentair Max-E-Therm Series MAX-E-THERM-400-NA Water Pressure Switch for Max-E-Therm heaters. Pentair Max-E-Therm Series MAX-E-THERM-200-HD Water Pressure Switch for Max-E-Therm heaters. Pentair Max-E-Therm Series MAX-E-THERM-333-HD Water Pressure Switch for Max-E-Therm heaters. Pentair Max-E-Therm Series MAX-E-THERM-400-HD Water Pressure Switch for Max-E-Therm heaters. Pentair ETi Series ETi250 — Pentair ETi Series ETi400 — Pentair MasterTemp / Max-E-Therm Series 461102 Included in all three master kits Pentair MasterTemp / Max-E-Therm Series 461100 Included in all three master kits Pentair MasterTemp / Max-E-Therm Series 461101 Included in all three master kits 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.
