Ruud U802VA050317MSA Error Code T047_F: Inducer Fan 5 Minute Lockout (Transient)
What Does Code T047_F Mean?
Fault code T047_F on the Ruud U802VA is a transient fault indicating that the inducer fan has triggered a 5-minute soft lockout. This occurs when the low-stage pressure switch fails to close within 60 seconds of the inducer motor starting. The pressure switch must close to prove that adequate exhaust draft exists before the furnace can attempt ignition. When this proof does not arrive within the time limit, the IFC enters a 5-minute pause before retrying.
The T (transient) prefix means this condition was intermittent rather than ongoing — it was observed once or briefly rather than persistently. On the Ruud U802VA, all lockout conditions including this one can be cleared by cycling power off and back on, or the furnace will automatically retry after the 5-minute period expires.
A blocked vent or flue pipe outside the home is a common cause — ice, snow, birds nests, or debris can obstruct the exhaust termination and prevent proper draft from building. Intermittent wind conditions can also affect draft momentarily. If the fault recurs repeatedly, the inducer motor, pressure switch, or sensing hose should be inspected by a professional.
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Pressure switch failed to close | Most common | ✗ Call a pro → |
When to Call a Professional
Contact a licensed HVAC technician if:
- If this fault recurs more than once or twice, call a technician to inspect the exhaust vent termination, inducer motor, and pressure switch
- A technician should check whether the vent pipe outside the home is blocked by ice, debris, or animal nests
- If the vent is clear and the fault continues, the inducer motor or pressure switch hose may need replacement
✓ Verified against manufacturer service manual — March 2026