Jandy Pool Heater Error Codes

12 codes · search by exact code, symptom, prefix, or model family

CHECK AUX MONITOR: direct answer

CHECK AUX MONITOR is a Jandy JXi display message, not a numbered fault code. The JXi Installation & Operation Manual (Section 10.2, Service Diagnostic Messages, page 48) lists the message AUX Monitor with one remedy: Check VersaFlo. VersaFlo is the optional integrated header bypass (Jandy kit JXIVFKIT). If the bypass assembly is intact and the message keeps returning, the manual hands the heater to qualified service personnel.

Jandy CHECK AUX MONITOR: full page · Raypak pool-heater code reference · CHECK FLOW: water-flow and filter checks

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Showing all 12 codes

Featured codes

  • AUX Monitor — AUX Monitor is one of the JXi controller's service diagnostic messages. The manual's
  • CHECK FLOW — Insufficient Water Flow Water pressure switch has detected insufficient flow through
  • FAULT-CHECK IGN CONTROL — Ignition Control System Fault Ignition control system has detected a problem preventi
  • FAULT-HIGH FLUE TEMPERATURE — High Flue Temperature Fault Exhaust gas temperature has exceeded the safe limit. Flue
  • FAULT-HIGH LIMIT — High Limit Temperature Fault Water temperature inside the heater exceeds the internal
  • FAULT-OPEN WATER SENSOR — Open Water Temperature Sensor Water temperature sensor circuit is open (broken). Disc

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Model families

Safe checks with an external tool or supply

These pages list the check you can do from outside the unit, with an optional external tool or maintenance supply. None of them repair an internal fault.

  • CHECK FLOW — Insufficient Water Flow Water pressure switch has detected insufficient flow through the heater. Pump not runn… external check: Pool filter cleaning supplies
  • FAULT-OPEN WATER SENSOR — Open Water Temperature Sensor Water temperature sensor circuit is open (broken). Disconnected sensor, broken w… external check: Digital pool thermometer

Other pool-heater references

The same fault families appear across brands:

Related troubleshooting guides

Manufacturer manuals

A codes

  • Jandy AUX Monitor error code
    CHECK AUX MONITOR is a Jandy JXi display message, not a numbered fault code. The JXi Installation & Operation Manual (Section 10.2, Service Diagnostic…

C codes

  • Jandy CHECK FLOW error code
    Insufficient Water Flow Water pressure switch has detected insufficient flow through the heater. Pump not running, low pump pressure, dirty filter, pr…

F codes

  • Jandy FAULT-CHECK IGN CONTROL error code
    Ignition Control System Fault Ignition control system has detected a problem preventing normal operation. Broken/pinched air pressure switch tubing, f…
  • Jandy FAULT-HIGH FLUE TEMPERATURE error code
    High Flue Temperature Fault Exhaust gas temperature has exceeded the safe limit. Flue temperature limit fault, loose connections, failed flue sensor. …
  • Jandy FAULT-HIGH LIMIT error code
    High Limit Temperature Fault Water temperature inside the heater exceeds the internal high limit. Insufficient water flow, blocked vent, limit switch …
  • Jandy FAULT-OPEN WATER SENSOR error code
    Open Water Temperature Sensor Water temperature sensor circuit is open (broken). Disconnected sensor, broken wire, failed temperature sensor. Check se…
  • Jandy FAULT-PUMP error code
    Pump Off Status Status message indicating the filter pump is currently OFF when heater is in Maintain Temp mode. Normal status — not an error. Pump is…
  • Jandy FAULT-SHORTED H2O SENSOR error code
    Shorted Water Temperature Sensor Water temperature sensor circuit shows a short. Faulty wiring or connection, failed water temperature sensor. Inspect…

L codes

  • Jandy LED Continuous On error code
    Ignition Control Fault Ignition Control Fault. The ignition controller has detected an internal failure. Failed ignition control module. Contact a qua…
  • Jandy LED Double Flash error code
    Flame Exists When No Call for Heat Flame Exists When No Call for Heat. Flame detected when the heater should not be firing. Turn off heater immediatel…
  • Jandy LED Single Flash error code
    Air Flow Fault Air Flow Fault. The air pressure switch has detected insufficient combustion air. Broken/pinched air pressure switch tubing, fan not op…
  • Jandy LED Triple Flash error code
    Ignition Lockout Ignition Lockout. Heater has made three unsuccessful attempts to fire and is in a soft lockout condition. Low gas supply, broken igni…