Jandy JXi 260 260,000 BTU Pool Heater with High Efficiency and Digital Temperature Control FS Error Fix: Flame Sense Fault

Error code FS on the Jandy JXi 260 260,000 BTU Pool Heater with High Efficiency and Digital Temperature Control means: Flame Sense Fault. The flame sensor detected flame absence during operation — the flame ignited successfully but was lost while the heater was running; different from IGN FAIL where the heater never ignited at all; causes include intermittent gas supply, wind blowing into the exhaust vent and extinguishing the flame, a dirty flame sensor rod that cannot sustain flame monitoring (clean with fine emery cloth), a cracked flame sensor ceramic insulator, or marginal gas pressure that drops under load; clean the flame sensor rod first as this is the most common cause

The most successful fix is "Replace the Flame Sensor Assembly" (medium difficulty, ~45 minutes). Estimated DIY cost: $15-$25. HomeMD has 2 community-ranked fixes for this error.

This error is rated medium severity. It should be addressed soon, but your appliance may still function in a limited capacity.

Yes — the top-ranked community fix ("Replace the Flame Sensor Assembly") is rated medium difficulty and takes about 45 minutes. Tools needed: Nut driver set (3/8 inch), Multimeter, Flathead screwdriver.

DIY cost: $15-$25. Professional repair typically costs $150-$250. Many homeowners save money by trying the top-ranked community fix first.

The Jandy JXi 260 260,000 BTU Pool Heater with High Efficiency and Digital Temperature Control has 8 other known error codes, including: AFS (Air Flow Switch Fault), AGS (Air/Gas Switch Fault), CE (Communication Error), CF (Combustion Fan Fault), FE (Flue Exhaust Fault), and 3 more.

Error code FS also appears on 1 other Jandy model: JXi 400,000 BTU Pool and Spa Heater with Digital Temperature Control. The fix may vary by model, so check each model's specific page for tailored repair steps.