Pentair Pentair MasterTemp 400,000 BTU Gas Pool/Spa Heater E06 Error Fix: Stack Flue Sensor (Alternate)

Error code E06 on the Pentair Pentair MasterTemp 400,000 BTU Gas Pool/Spa Heater means: Stack Flue Sensor (Alternate). An alternate stack flue sensor code that indicates the same over-temperature condition as E05. Some MasterTemp firmware versions use E06 instead of or in addition to E05 for stack flue conditions. Same causes and remedies as E05. Some technicians report E06 appearing when the stack flue sensor cable or connector has an intermittent connection. Check the sensor wiring in addition to flow-related causes.

The most successful fix is "Replace Stack Flue Sensor and Inspect Flow Components" (medium difficulty, ~60 minutes). Estimated DIY cost: $40-$60. HomeMD has 2 community-ranked fixes for this error.

This error is rated critical severity. It is generally not urgent and can often be resolved with a simple DIY fix.

Yes — the top-ranked community fix ("Replace Stack Flue Sensor and Inspect Flow Components") is rated medium difficulty and takes about 60 minutes. Tools needed: T20 Torx screwdriver, Multimeter, Zip ties.

DIY cost: $40-$60. Professional repair typically costs $250-$350. Many homeowners save money by trying the top-ranked community fix first.

The Pentair Pentair MasterTemp 400,000 BTU Gas Pool/Spa Heater has 8 other known error codes, including: AFS (Air Flow Switch Fault), AGS (Auto Gas Shutoff), bd (Board Error), BURNER DEBRIS (Burner Tray Obstruction), BYPASS VALVE (Bypass Valve Adjustment Needed), and 3 more.

Error code E06 also appears on 3 other Pentair models: Pentair IntelliFlo VSF Variable Speed Pool Pump, Pentair IntelliFlo3 VSF Variable Speed Pool Pump, Pentair UltraTemp Heat Pump Pool Heater. The fix may vary by model, so check each model's specific page for tailored repair steps.