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HTP Error Code F02: Supply sensor failure (Boiler)

Updated · by Aurora Star Tech Inc.

HTP error code F02 on a boiler means: Supply sensor failure. It is also called HTP diagnostic code F02.

High severityBoilerElite EL

Homeowner? What HTP code F02 means for you

Call a technician Your boiler is reporting: Supply sensor failure. The boiler has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.

Safe things you can check yourself

  • Check the thermostat: right mode (Heat or Cool), set a few degrees past room temperature, and fresh batteries if it uses them.
  • Make sure the unit has power: its on/off switch (often looks like a light switch near the unit) is ON and the breaker in the electrical panel is not tripped.
  • Look at the pressure gauge on the boiler. If it reads much lower than usual or near zero, or water is leaking, call a technician.
  • Outside, make sure the intake and exhaust pipes or vent cap are not blocked by snow, ice, leaves or a nest.
  • Check that the boiler gas valve is open (handle in line with the pipe).
  • Try one reset: turn the power off for 30 seconds, then back on. If the code comes back, stop resetting and call a technician.

Call (647) 657-2977Book a service call

Licensed technicians serving Vaughan, Toronto and the GTA.

What does HTP error code F02 mean?

Supply (outlet) temperature sensor has failed. Lockout, pump on. Control: FAULT light red steady and LOCKOUT shown on lower line; reset with RESET held over 1 second after repair.

Applies to: EL-80, EL-110, EL-150, EL-220, EL-299, EL-399 (N/LP)

Common causes of HTP code F02

  • Sensor wiring or connection fault
  • Failed supply thermistor
  • Control board not providing 5 V
Safety: Gas, electrical and refrigerant work must be done by a licensed technician. Turn off power and gas before servicing, never bypass a safety control, and always follow the manufacturer's manual for your exact model.

HTP models that use code F02

EL-80 LPEL-80 NEL-110 LPEL-110 NEL-150 LPEL-150 NEL-220 LPEL-220 NEL-299 LPEL-299 NEL-399 LPEL-399 N

Other HTP Boiler codes

CodeMeaning
DHWTemperature blocking - DHW demand
E03System sensor failure (cascade)
E07Flue temperature high
E19Line voltage frequency out of range
F00Water high temperature (ECO)
F01Flue temperature switch / low water
F03Return sensor failure
F04Flue sensor failure
F05Supply temperature high
F06Return temperature high
F09No flame on ignition
F10Flame loss

All HTP Boiler error codes →

HTP code F02: homeowner questions

What does HTP code F02 mean?

Supply sensor failure. Supply (outlet) temperature sensor has failed. Lockout, pump on. Control: FAULT light red steady and LOCKOUT shown on lower line; reset with RESET held over 1 second after repair.

Is it safe to keep using my boiler with code F02?

It depends on the cause. The boiler has locked out or cannot run properly. One reset is fine; if the code comes back, it needs a licensed technician to find the cause.

Can I reset HTP code F02 myself?

You can try one reset (power off for 30 seconds, then on). If HTP code F02 comes back, the cause is still there and a licensed technician should check it.

Who can fix HTP code F02 near me?

Aurora Star Tech Inc. repairs HTP boilers in Vaughan, Toronto and across the GTA. Call (647) 657-2977 or book a service call online.

Homeowner help: Boiler Not Heating: What to Check

Troubleshooting guides

Source: Elite EL-80 N Installation Manual (LP-293), p. 69. Written in our own words as a summary; always check the original manual.

General guidance for qualified technicians. The manufacturer's installation and service manual and local codes always take priority. Aurora Star Tech is not affiliated with, endorsed by or sponsored by any equipment manufacturer; brand and model names are used only to identify equipment and belong to their owners.

Emergency Boiler Repair

647-657-2977