What does error code E05 mean on a Pentair pool heater?

Stack flue sensor fault. The stack flue sensor is open (E05) or shorted (E06).

Can I fix Pentair code E05 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 E05?

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 E05 / E06: Stack flue sensor fault

What E05 means

The stack flue sensor is open (E05) or shorted (E06).

Also shown as: E06, depending on the model.

Likely causes

Flue 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.

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.