Rheem R96VA0702317MSA Error Code 23: HALC Open
What Does Code 23 Mean?
A code 23 on the Rheem R96VA0702317MSA indicates an open HALC (High Altitude Limit Control) circuit, which prevents gas heating while allowing cooling and fan-only operation to continue. This code is triggered when the IFC cannot detect continuity between pins 3 and 5 of connector P1 on the furnace control board.
This furnace model does not include an actual HALC device. Instead, a jumper wire is installed between pins 3 and 5 of connector P1 to complete the circuit. The HALC circuit code exists in the IFC fault list because the same control board is used across multiple models in the R96V family, some of which do have a physical HALC control. On this model, code 23 almost always means the jumper wire has come loose, disconnected, or broken.
When this fault is active, the blower motor runs at maximum heat speed and the gas valve is de-energized as a safety measure. The circuit must be completed before gas heating will resume. A qualified HVAC technician needs to access the furnace control board, locate connector P1, and verify that the jumper wire between pins 3 and 5 is properly seated and undamaged.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Jumper wire between pins 3 and 5 of connector P1 disconnected or broken | Most common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- Call a technician to inspect connector P1 on the IFC and verify the jumper wire between pins 3 and 5 is properly connected — this is typically a quick repair but requires accessing the control board safely
✓ Verified against manufacturer service manual — March 2026