![Freeflow high limit thermistor, 73992 Freeflow high limit thermistor, 73992](https://cdn11.bigcommerce.com/s-whbac/images/stencil/300x300/products/1779/4305/73992__86914.1671806943.jpg?c=2)
This Pentair Sta-Rite/Mastertemp Thermistor Temperature Sensor, 42001-0053S will normally give you and error code of E01 if this has to be changed. This is an easy change for a experienced pool or spa techican. Once installed the the pool heater will give you accurate temperaure readings.