Error Code T086_F
Low

Rheem R802VA07542117MSA Error Code T086_F: Suction Pressure Sensor Failure

TL;DR
On a two-stage Rheem R802VA, the suction pressure transducer used for EXV superheat control has failed. Heating is unaffected but cooling system operation may be impaired. A technician should replace the sensor.
Disclaimer
This article is for informational purposes only and does not guarantee the accuracy or completeness of the information provided. Always turn off power and gas supply before attempting any repairs. If you smell gas, leave immediately and call your gas company. Consult a licensed HVAC technician for diagnosis and repair. Any actions taken based on this information are at your own risk.

What Does Code T086_F Mean?

Fault code T086_F on the Rheem R802VA is a troubleshooting-level fault for two-stage models only. It indicates that the suction pressure transducer — a sensor used alongside the suction line thermistor (T085_F) by the Electronic Expansion Valve system — has failed or is outputting an out-of-range signal.

The EXV system uses both suction line temperature and suction pressure to calculate refrigerant superheat. The suction pressure transducer converts refrigerant pressure at the compressor suction port into an electrical signal that the IFC or EXV controller reads. Without accurate pressure data, the EXV cannot compute superheat and may fall back to a default valve position, reducing cooling efficiency.

Furnace heating operation is not affected by this fault. The T (troubleshooting) prefix indicates an intermittent observation. Potential causes include a failed transducer, a disconnected transducer electrical connector, or a refrigerant system issue that is causing the suction pressure to read outside the transducer's valid range.

Common Causes

Cause Likelihood DIY?
Failed suction pressure transducer Most common ✗ Call a pro →
Disconnected pressure transducer wiring Common ✗ Call a pro →

When to Call a Professional

Contact a licensed HVAC technician if:

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Sources

  1. Installation Instructions - 80+ Upflow/Horizontal Two-Stage and Single-Stage Bluetooth Communicating Gas Furnaces with Constant CFM/PWM Blower

✓ Verified against manufacturer service manual — March 2026