Pentair Flue Temperature Sensor 42002-0024S for Sta‑Rite Max‑E‑Therm – Direct OEM Replacement, Plug-In

The Pentair 42002-0024S is a direct-replacement stack flue temperature sensor designed for Sta‑Rite Max‑E‑Therm pool and spa heaters to restore reliable temperature detection and heater operation.

If your pool or spa heater is showing error codes, failing to fire, or cutting out unexpectedly, the issue can often be a worn or faulty flue sensor. The 42002-0024S is a compact electrical sensor engineered to fit the stack/flue assembly used in Sta‑Rite Max‑E‑Therm series heaters. It measures flue gas temperature and communicates with the heater’s control board so the system can regulate combustion safely and efficiently.

How does this sensor affect my heater’s performance?

The flue sensor monitors temperature inside the flue to ensure proper combustion and safe shutdowns when temperatures are out of range. A faulty sensor can cause the heater to go into lockout or misread operating conditions, leading to poor heating consistency. Replacing a bad sensor brings the control logic back to correct temperature readings and predictable operation.

• Restores accurate flue temperature feedback to the control board
• Reduces false lockouts and intermittent shutdowns
• Helps the heater maintain steady on/off cycling

Is the Pentair 42002-0024S easy to install?

Installation typically requires basic hand tools and safe power-disconnection procedures; it plugs into the existing wiring harness and mounts in the flue stack. No special calibration is usually necessary because it’s a direct OEM-equivalent replacement. Always follow the heater manufacturer’s instructions and power-safety steps when replacing electrical components.

• Direct-fit replacement for Sta‑Rite Max‑E‑Therm models
• Mounts in the flue stack with the original bracket or clamp
• Plugs into the heater’s existing connector—no extra wiring needed

What compatibility and part‑matching should I check?

Confirm your heater model and the existing sensor part number before ordering—42002-0024S matches Sta‑Rite Max‑E‑Therm heater electrical systems. If your unit uses the same flue-sensor form factor and connector type, this Pentair sensor will serve as a proper replacement. For non‑Sta‑Rite heaters, verify physical fit and electrical specifications first.

• OEM part number: 42002-0024S (Pentair)
• Intended for Sta‑Rite Max‑E‑Therm series heaters
• Check connector type and mounting orientation before purchase

How can I tell the sensor is failing before replacement?

Signs of a failing flue sensor include repeated ignition failures, error codes referencing temperature or flame sense, or sudden heater lockouts. Visual inspection may reveal corrosion, frayed wires, or a damaged probe tip. If diagnostics point to inaccurate temperature readings or intermittent connections, replacing the sensor is a practical troubleshooting step.

• Heater displays temperature or sensor-related error codes
• Intermittent operation or unexplained shutdowns
• Visible wire damage or sensor corrosion in the flue area

Who is this for: The Pentair 42002-0024S is intended for pool and spa owners, service technicians, and maintenance professionals working with Sta‑Rite Max‑E‑Therm gas heaters who need an OEM-quality flue temperature sensor replacement. Choose this part when your heater shows sensor-related errors or when routine maintenance indicates the flue sensor is degraded. If you’re unsure about compatibility, consult your heater’s model plate or a certified service technician before ordering.