Pentair Voltage Selector Plug Kit (120V/240V) for MasterTemp® & Max-E-Therm® Heaters | 42001-0105S
The Pentair 42001-0105S is an OEM voltage selector plug kit used on the electrical system of Pentair MasterTemp and Sta-Rite Max-E-Therm pool/spa heaters. This plug set is used to configure the heater for the correct incoming line voltage (120V or 240V) so the transformer and control system receive the proper power input.
Key Features
- Selects 120V or 240V operation: configures the heater for the supply voltage specified by the installation.
- OEM Pentair/Sta-Rite kit: correct plug style and fit for compatible heater control/transformer wiring layouts.
- Restores correct power configuration: helpful when a plug is missing, damaged, overheated, or incorrectly set.
- Supports reliable control power: incorrect voltage selection can lead to control issues or component damage.
Compatibility
- Used on: Pentair MasterTemp heater electrical systems (model/revision dependent)
- Used on: Pentair MasterTemp 125 heater electrical systems (where specified)
- Used on: Sta-Rite Max-E-Therm heater electrical systems (model/revision dependent)
Tip: Always match the part number and wiring diagram for your specific heater model and revision before ordering.
Common Symptoms of a Bad or Incorrect Voltage Selector Plug
- Heater control panel/display will not power on (after confirming breaker, wiring, and transformer condition)
- Intermittent resets or erratic control behavior
- Evidence of heat damage, melting, discoloration, or loose/poor contact at the plug connection
- Heater was recently rewired for a different voltage and now will not operate correctly
Specifications
- Brand: Pentair
- Part Number: 42001-0105S
- Part Type: Voltage selector plug kit
- Voltage Options: 120V / 240V (heater configured)
- Application: MasterTemp / Max-E-Therm heater electrical system
- Quantity: 1 kit
Installation Notes
- Turn off power at the breaker before opening the heater or servicing electrical components.
- Confirm the supply voltage (120V vs 240V) and follow the heater wiring diagram exactly when installing the selector plug.
- Ensure all connections are fully seated and secure; loose electrical connections can overheat and fail.
- If you’re unsure about wiring, have a qualified technician perform the installation.
Related Products
- Search Aqua Pool Supply for 42001-0105S
- Dual Voltage Transformer Kit (42001-0107S)
- MasterTemp electrical parts
- Max-E-Therm electrical parts
- MasterTemp 125 replacement parts
- Pool heater transformers
Maintenance Tips
- Keep the heater cabinet properly closed and sealed to reduce moisture intrusion that can corrode electrical connections.
- Inspect wiring and plug connections seasonally for looseness, corrosion, or heat discoloration.
- If you experience repeated electrical failures, verify correct supply voltage, grounding/bonding, and look for water intrusion or rodent damage.
