Pentair Pentair MasterTemp 400,000 BTU Gas Pool/Spa Heater AGS Error Fix: Auto Gas Shutoff

Error code AGS on the Pentair Pentair MasterTemp 400,000 BTU Gas Pool/Spa Heater means: Auto Gas Shutoff. The automatic gas shutoff has activated. The gas valve has been commanded to close. This is a safety shutdown typically triggered by another fault condition (high limit, flame rollout, stack flue, etc.). Check for other active error codes that may have triggered the gas shutoff. Reset the heater by cycling power. If AGS appears without other codes, the gas valve itself may be malfunctioning — professional gas appliance service is recommended.

The most successful fix is "Diagnose and Replace Faulty Gas Valve" (hard difficulty, ~90 minutes). This fix costs nothing. 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 ("Diagnose and Replace Faulty Gas Valve") is rated hard difficulty and takes about 90 minutes. Tools needed: Phillips screwdriver, Multimeter, Adjustable wrench, Leak detection solution.

DIY cost: $0. Professional repair typically costs $300-$450. 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), bd (Board Error), BURNER DEBRIS (Burner Tray Obstruction), BYPASS VALVE (Bypass Valve Adjustment Needed), CF (Combustion Fan Fault), and 3 more.