Ruud Furnace Code 71
Soft lockout
Inducer fault. The control is measuring too much or too little current on the inducer (draft motor) circuit. Gas heat is blocked; cooling still runs. The manual notes this can appear harmlessly if power is lost and restored within 30 seconds while the furnace is heating.
Manual wording: “INDUCER FAULT ... This fault indicates that the inducer is not working properly. ... The fault is displayed when too much or too little current is detected on the inducer circuit.”
Documented for: (-)97V modulating furnaces
Likely causes, most common first
- Power outage
- Bad wiring to inducer
- Bad inducer
- Bad furnace control
What you can safely check yourself
- Power cycle once at the furnace switch - the manual's own first solution is "Reset power to unit and clear fault", which clears the code after a brief power blip.
When to call a technician
If it does not clear on a reset, the inducer motor, its wiring or the control needs a technician.
A Ruud furnace throwing this code repeatedly has a reason — clearing the code without fixing the cause just hides it.
Source
- Installation Instructions for Upflow Condensing Modulating, Communicating Gas Furnaces - (-)97V Series (92-24161-126-04) (Rheem Manufacturing Company (Ruud brand), U97V series modulating condensing gas furnace (and U98V); TABLE 18 normal operation codes, TABLE 19 fault codes, pages 94-104) · checked 2026-08-25