What does error code E01 mean on a Pentair pool heater?

Water temperature sensor fault. The water temperature sensor is open (E01) or shorted (126).

Can I fix Pentair code E01 myself?

Start with these safe checks: Note the code and call a qualified tech. Sensor replacement is inside the heater cabinet.

When should I call a technician for code E01?

Sensor replacement is inside the heater cabinet. Smell gas? Leave right away, don't touch light switches or phones inside, and call your gas utility or 911 from outside. Never open a gas valve, burner, gas line, vent or flue connection, or bypass a safety switch. Repeated lockouts, scorching, soot, or a CO alarm mean shut it off and call a licensed gas technician.

Pentair Pool Heater Error Code E01 / 126: Water temperature sensor…

What E01 means

The water temperature sensor is open (E01) or shorted (126).

Also shown as: 126, depending on the model.

Likely causes

Water temperature sensor or wiring fault

Safe first checks

Note the code and call a qualified tech.

When to stop

Sensor replacement is inside the heater cabinet.

Parts that may help

Only order a part once the checks above point to it, and match the part number to your model.

Sundance/Jacuzzi 3-Pin Temperature Sensor, 12 ft Cable – 6600-751$59.99

Checked against: Pentair MasterTemp heater installation and user's guide (Table 8: error and fault codes). Codes can differ by model and year, so confirm with your owner's manual.