DIY Error Codes

Jandy JXi gas pool heater Fault HIGH FLUE TEMPERATURE

The flue sensor saw too much heat at the exhaust, so the heater stopped burning. Jandy's first remedy is to have a service professional review it.

Note the message and contact a qualified service technician, as Jandy's manual directs for HIGH FLUE TEMPERATURE.

Start the fix →When to call a pro ↓
Full answer & models

Jandy JXi HIGH FLUE TEMPERATURE means the flue temperature limit tripped and the heater stopped. Jandy says to have a service professional review it.

Applies to: JXi 200JXi 260JXi 400
Also searched as: Jandy heater FAULT - HIGH FLUE TEMPERATURE, Jandy JXi high flue temp, Jandy heater high flue temperature, Jandy pool heater flue temp fault

Gas appliance. Owner checks only; Jandy says a qualified professional service technician must do all service.
Why
Jandy, what to do if you smell gas: immediately switch off main gas supply; do not try to light any appliance; do not touch any electrical switch; do not use any phone in your building; immediately call your gas supplier from a neighbor's phone and follow the gas supplier's instructions; if you cannot reach your gas supplier, call the fire department. Installation and service must be performed by a qualified installer, service agency or the gas supplier. Jandy: ELECTRICAL SHOCK HAZARD. This heater contains wiring that carries high voltage. Contact with these wires may result in severe injury or death. Jandy servicing safety: service procedures can be hazardous because they involve fuel gas, electricity, moving parts and procedures which require testing or temporary bypass of safety controls, so the heater must be serviced only by a qualified professional service technician. Improper installation or maintenance can cause nausea or asphyxiation from carbon monoxide in flue gases which could result in severe injury, or death.

What HIGH FLUE TEMP means

The flue sensor saw too much heat at the exhaust, so the heater stopped burning. Jandy's first remedy is to have a service professional review it.

More detail
Jandy's JXi manual (Section 10.2, Service Diagnostic Messages, p. 47) lists "FAULT - HIGH FLUE TEMPERATURE" as a flue temp limit fault. Its remedies are: contact a service professional to review the fault condition, identify and correct loose connections, replace the flue sensor, and refer to qualified service personnel. Section 1.8 (p. 7) says the flue temperature sensor monitors temperature at the exhaust flue, and if excessive temperatures are detected, combustion stops and a fault is displayed.

5-minute checks

Fix it step by step

Step 1 of 2

  1. Note the fault and leave the vent alone

    • 2 min
    • None
    • DIY

    Safety: Gas appliance. Owner checks only; Jandy says a qualified professional service technician must do all service.

    Jandy: contact a service professional to review it.

    More detail

    Note the fault and leave the vent alone.

    Write down the message and when it appeared. Jandy's first remedy for this fault (p. 47) is to contact a service professional to review the fault condition. Gas appliance. If you smell gas, do not touch switches or phones; call your gas supplier from a neighbor's phone.

    Did the code clear?

  2. Call a qualified service technician

    • Decision
    • None
    • Pro decision

    Stop here and book a qualified technician.

    More detail

    Call a qualified service technician.

    The other remedies Jandy lists (p. 47), correcting loose connections and replacing the flue sensor, are technician work. Jandy (Section 11, p. 48): call a qualified service technician to perform all service and repairs on the heater. Do not open the heater cabinet yourself.

    Still showing HIGH FLUE TEMP?Need a pro → call a pro

Code cleared. Nice work.

Watch the display for a day to make sure it stays clear.

Back to top

Fixed after any step? Watch the display for a day to make sure it stays clear. Still HIGH FLUE TEMP after step 2? call a pro.

Call a pro if…

  • You smell gas (switch off the main gas supply if you can, then call your gas supplier from a neighbor's phone).
  • HIGH FLUE TEMPERATURE keeps coming back after the owner checks.
  • Anything that needs the heater cabinet opened, wiring checked, or gas pressure tested.

FAQ

What does HIGH FLUE TEMPERATURE mean on a Jandy JXi?

A flue temp limit fault, per Section 10.2 (p. 47). The flue temperature sensor watches the exhaust flue; when it detects excessive temperature, combustion stops and the fault is displayed (p. 7).

Can I fix a JXi high flue temperature fault myself?

Jandy's remedy starts with contacting a service professional to review the fault condition. The other listed fixes (loose connections, replacing the flue sensor) are technician work.

Source: Jandy JXi Gas-Fired Pool and Spa Heater Installation & Operation Manual (H0574300 Rev M), Section 10.2 Service Diagnostic Messages (p. 47); Section 1.8 (p. 7); Section 9.5.1 (p. 44); safety, pp. 1, 32, 38 and 48. Written by the DIY Error Codes team. Updated 2026-10-16. DIY Error Codes is independent and not affiliated with or endorsed by Jandy.