Trane Error Code E7.2: Redundant relay (HLO output) on with no call (Furnace)

Updated October 13, 2026 · by Aurora Star Tech Inc.

Trane error code E7.2 on a furnace means: Redundant relay (HLO output) on with no call. It is also called Trane diagnostic code E7.2.

Critical severityFurnaceTrane S8V2

Homeowner? What Trane code E7.2 means for you

Stop and call Your furnace is reporting: Redundant relay (HLO output) on with no call. This code is a safety shutdown. Turn the furnace off and call a licensed technician. Do not keep resetting it. If you smell gas, leave the house and call your gas utility or 911 from outside.

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.

Call (647) 657-2977 Book a service call

Licensed technicians serving Vaughan, Toronto and the GTA.

What does Trane error code E7.2 mean?

The IFC high limit output relay is stuck on.

Applies to: Trane S8V2 only

Common causes of Trane code E7.2

Failed relay on IFC
Wiring back-feed on HLO

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.

Trane models that use code E7.2

S8V2A040M3PCB S8V2A040M3PD S8V2B060M4PCB S8V2B060M4PD S8V2B080M4PCB S8V2B080M4PD S8V2C080M5PCB S8V2C080M5PD S8V2C100M5PCB S8V2C100M5PD S8V2D120M5PCB S8V2D120M5PD

Other Trane Furnace codes

Code	Meaning
E4.1	Reverse airflow limit open
E4.2	Flame rollout switch open
E6.1	120 V polarity reversed
E6.2	Ground not detected
E6.3	Igniter open or igniter relay fault
E7.1	1st stage gas valve (MVL) powered with no call
E11	Gas valve relay / valve circuit fault
E12	Control fuse open
E13	Blower motor size / OEM ID mismatch
E14	Configuration file error
E17	Blower motor communication error
E23	Menu data not received by combustion micro (CCM)

All Trane Furnace error codes →

Trane code E7.2: homeowner questions

What does Trane code E7.2 mean?

Redundant relay (HLO output) on with no call. The IFC high limit output relay is stuck on.

Is it safe to keep using my furnace with code E7.2?

No. Code E7.2 is a safety shutdown, so keep the furnace off until a licensed technician has checked it.

Can I reset Trane code E7.2 myself?

Do not keep resetting it. Repeated resets can hide a safety problem; a licensed technician needs to find the cause.

Who can fix Trane code E7.2 near me?

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

Homeowner help: Furnace Not Turning On: What to Check · Furnace Blinking Light: What the Flash Codes Mean

Troubleshooting guides

Blowing cold air All brands · Furnace
No heat All brands · Furnace
Short cycling All brands · Furnace
Reading and clearing fault history - Trane S-Series IFC Trane · Furnace

Source: Trane FNR-SVX003A-EN (S8V2 installer's guide) - section Integrated Furnace Control Display Codes, Table 37 Error codes; Trane FNR-SVX003A-EN (S8V2 installer's guide) - section Troubleshooting (flowcharts). 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.