Pentair Pool Heater E06 Error Code

Updated 2026-08-29 · review status: manual-verified Last verified: 2026-08-29

Quick answer

Shorted Stack Flue Sensor Stack flue sensor circuit is shorted. The SFS thermistor is reading near-zero resistance, which the control board interprets as an impossibly high temperature. Water intrusion into the sensor or its connector causing a short, sensor element failed short from overheating, wiring harness pinched or chafed causing a short to ground. Disconnect the SFS and measure resistance.

Severity: high · DIY difficulty: intermediate

Safety

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What E06 means

Shorted Stack Flue Sensor Stack flue sensor circuit is shorted. The SFS thermistor is reading near-zero resistance, which the control board interprets as an impossibly high temperature. Water intrusion into the sensor or its connector causing a short, sensor element failed short from overheating, wiring harness pinched or chafed causing a short to ground. Disconnect the SFS and measure resistance. Near-zero (0Ω) resistance confirms a shorted sensor — replace the SFS. Inspect the wiring harness for chafe points in the high-heat flue area. After replacement, verify the vent is not restricted, which can cause the SFS area to overheat.

Causes, ranked

  1. 1. Stack flue sensor failed shorted common pro-only

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  2. 2. Damaged sensor wiring shorting the stack flue sensor circuit occasional diy-ok

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Parts & supplies for Pentair Pool Heater: filters, control boards, sensors, and common replacement parts.

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Sources

  • PoolDial error-code reference (manual-backed) — verified 2026-08-29
  • Pentair MasterTemp/Max-E-Therm Heater Installation & User's Guide (Section 5 Troubleshooting) — verified 2026-08-29