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Troubleshooting code

Back to all A952V080BU4SB error codes

Trane A952V080BU4SB E7.2 troubleshooting

Redundant relay energized when it should be off. Use this page to document the issue and prepare for service. GreenFlow should handle diagnosis for electrical, refrigerant, lockout, or recurring conditions.

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What the code means

E7.2: Redundant relay energized when it should be off

The RunTru by Trane A952V error-code table identifies E7.2 when the redundant relay HLO output is energized when it should not be.

System area
Redundant relay / HLO output
Service level
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Safe checks before calling

  • Confirm the thermostat is on, set correctly, and calling for heating or cooling.
  • Check the air filter and visible return-air path for obvious airflow restrictions.
  • Look around the outdoor unit for leaves, snow, ice, or other visible obstructions without opening the cabinet.
  • Take photos of the thermostat, outdoor unit, nameplate, and any visible flash pattern before scheduling service.

When to stop and call GreenFlow

Call GreenFlow if the code repeats, the system is locked out, heating or cooling is not restored, there is ice buildup, electrical odor, unusual noise, or any issue involving pressure switches, sensors, wiring, refrigerant, reversing-valve operation, or warranty coverage.

Share the visible code, model and serial number if available, photos, current symptoms, and whether the issue affects heating, cooling, or both.

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E7.2 questions

What does E7.2 mean on a Trane A952V080BU4SB?

The RunTru by Trane A952V error-code table identifies E7.2 when the redundant relay HLO output is energized when it should not be.

What Trane message is associated with E7.2?

The Trane source used for this page associates E7.2 with "Redundant relay energized when it should be off". Match the visible display text, LED pattern, or alert wording to the exact code whenever possible.

What system area does E7.2 point to?

This code is grouped under redundant relay / hlo output in the source-backed Trane troubleshooting data.

Which Trane documentation supports this E7.2 page?

Source-backed RunTru by Trane FNR-SVX005A-EN integrated furnace control error-code table for A952V variable-speed furnaces.

What information should be captured for E7.2 before clearing alerts?

Capture the exact code, any displayed alert text, the model and serial number, thermostat or control status, operating mode, symptoms, and photos of the display or LED pattern before the alert history is cleared.

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