Rheem R802VA07542117MSA Error Code *T086_F: Suction Pressure Sensor Failure (Two-Stage Only)

What Does Code *T086_F Mean?

Your two-stage, variable-speed R802VA07542117MSA uses the Bluetooth Communicating IFC (Integrated Furnace Control) to help manage the cooling system's electronic expansion valve (EXV). The suction pressure transducer converts the refrigerant pressure at the compressor suction port into an electrical signal, and the control combines that pressure with the suction line temperature to calculate superheat, which tells the EXV how much refrigerant to feed the cooling coil. Rheem lists T086_F as a two-stage-only fault, logged when the transducer's signal reads outside the valid range, usually from a failed transducer or a disconnected connector.

Because the transducer serves the cooling side rather than combustion, furnace heating is unaffected and the burner operates normally. Rheem rates T086_F as low severity. What can suffer is cooling efficiency: without a reliable suction pressure signal the EXV cannot compute superheat and may default to a fixed valve position, so air conditioning performance can slip even though heating stays normal.

T086_F is the pressure half of this board's EXV superheat sensing pair. Its partner is T085_F, the suction line temperature thermistor; together those two feed the superheat math, and T088_F flags when the combined EXV measurements come out inconsistent. This EXV group is separate from the air-temperature sensors (T081_F return, T082_F supply, T084_F outdoor) and from T087_F, the board's own temperature sensor. All are low-severity monitoring faults, not hard lockouts.

One nuance specific to a pressure transducer: an out-of-range reading does not always mean the sensor is bad. If the refrigerant system's actual suction pressure is genuinely abnormal, a healthy transducer can report a value the control still sees as outside the expected window, which is why a technician verifies system pressures rather than assuming the sensor has failed.

What You'll Notice

• The alphanumeric display shows "T086_F", or the LED blinks the code one digit at a time with a roughly three-second pause between digits
• Heating continues to run normally with no change at the registers
• Air conditioning may cool less efficiently or feel weaker than usual
• The fault stays logged in the Bluetooth contractor app after a power cycle
• No lockout occurs, and the effect is most noticeable during cooling operation

Common Causes

How This Is Diagnosed

A technician locates the suction pressure transducer on the refrigerant suction line and its connector at the control, then confirms the connector is secure and checks the transducer's output signal against the expected range. Because a valid transducer can read out of range when the refrigerant system's actual pressures are abnormal, the technician also measures true system pressures with gauges before condemning the sensor.

If the wiring and connector are sound and the measured system pressure disagrees with what the transducer reports, the transducer is faulty; if the system pressure itself is out of range, the refrigerant circuit is investigated. This is informational only; refrigerant-side work requires refrigeration certification and is not homeowner-safe.

When to Call a Professional

This code involves components that are not homeowner-serviceable, so have a licensed HVAC technician diagnose and repair it. Keep in mind:

• The code stays active and your cooling system is underperforming
• You also see T085_F or T088_F, pointing to a broader EXV superheat sensing problem
• Air conditioning efficiency has dropped since the code appeared
• You want the refrigerant system pressures verified before deciding whether the transducer or the charge is at fault

✓ Verified against manufacturer service manual — March 2026