Jandy JXi 400,000 BTU Pool and Spa Heater with Digital Temperature Control WF Error Fix: Water Flow — Secondary Flow Indication

Error code WF on the Jandy JXi 400,000 BTU Pool and Spa Heater with Digital Temperature Control means: Water Flow — Secondary Flow Indication. A secondary water flow fault indication — similar to FLO but may be triggered by a different flow verification method or threshold; check pump operation, filter condition, and valve positions; ensure the heater bypass valve is not diverting too much water around the heater; verify the pump is running at sufficient speed for the heater to register flow

The most successful fix is "Test and Replace Flow Sensor Assembly" (medium difficulty, ~45 minutes). Estimated DIY cost: $20-$30. 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 ("Test and Replace Flow Sensor Assembly") is rated medium difficulty and takes about 45 minutes. Tools needed: Adjustable wrench, Multimeter, Teflon tape.

DIY cost: $20-$30. Professional repair typically costs $130-$180. Many homeowners save money by trying the top-ranked community fix first.

The Jandy JXi 400,000 BTU Pool and Spa Heater with 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 WF also appears on 1 other Jandy model: JXi 260 260,000 BTU Pool Heater with High Efficiency and Digital Temperature Control. The fix may vary by model, so check each model's specific page for tailored repair steps.