Rheem R96VA0702317MSA Error Code 58: Water Circuit Open
What Does Code 58 Mean?
A code 58 on the Rheem R96VA0702317MSA is a critical fault indicating the IFC cannot detect electrical continuity between pins 1 and 2 of connector P4 on the furnace control board. The R96VA uses two water sensors to detect condensate leaks in the collector box area. When both sensors are properly installed and connected, there is electrical continuity between those pins. An open circuit at P4 means the water sensor circuit is incomplete, which prevents gas heating while allowing cooling and fan-only operation to continue.
The water sensor system is a safety feature specific to condensing furnaces like the R96VA, which produce substantial condensate during operation. The sensors detect if water is accumulating where it should not be, indicating a drain blockage or internal water leak. The code 58 specifically means the sensor circuit itself is broken — distinct from code 59, which means the sensors are intact and actively detecting water.
The most common cause of code 58 is damaged wiring between the IFC and the water sensors, or a loose connection at connector P4 on the control board. A water sensor that was removed and not reinstalled during prior service work will also break continuity. A technician needs to inspect the wiring harness to the water sensors, check that both sensors are physically installed in the collector box, and verify that connector P4 is properly seated on the IFC.
Common Causes
When to Call a Professional
Contact a licensed HVAC technician if:
- Call a technician to inspect the wiring to both water sensors and verify connector P4 is properly seated on the IFC — damaged or disconnected wiring to the sensors must be repaired for gas heating to resume
- The technician should confirm both water sensors are physically installed in the collector box and that no prior service work inadvertently removed one or damaged the sensor wiring
✓ Verified against manufacturer service manual — March 2026