Ruud U96VA0702317MSA Error Code 44: Low Pressure Switch Closed, Inducer Off

What Does Code 44 Mean?

A code 44 on the Ruud U96VA0702317MSA is a critical fault indicating the low pressure switch is in the closed position before the heating cycle begins, when the inducer motor is not running. The pressure switch should only close when the running inducer creates sufficient negative pressure in the venting system. Finding it already closed before the inducer starts indicates the switch has failed, is stuck, or has been deliberately bypassed — any of which means the furnace cannot rely on this switch to verify safe venting. Gas heating is blocked while cooling and fan-only modes remain available.

The IFC performs a pre-ignition safety check on the pressure switch at the start of every heat cycle. If the switch is already closed, the IFC determines it cannot trust this safety device to reflect actual venting conditions and refuses to proceed with ignition. A pressure switch with mechanically stuck or welded contacts is the most common hardware failure. Deliberate bypassing of the pressure switch — sometimes done as a temporary field workaround — removes a critical safety layer and is a dangerous modification.

An abnormally high negative pressure already present in the vent system before furnace startup is a less common cause. A technician must determine the exact cause — stuck switch, bypass, or unusual system pressure — and correct it before gas heating can resume.

Common Causes

When to Call a Professional

Contact a licensed HVAC technician if:

• Call a technician to test the low pressure switch for stuck-closed contacts and inspect the pressure switch circuit for any unauthorized bypasses — both conditions are safety concerns requiring immediate repair
• The technician should replace the switch with the correct part for this model and verify there are no unusual vent system conditions creating pre-existing negative pressure

✓ Verified against manufacturer service manual — March 2026