Rheem R802VA07542117MSA Error Code A047_F: Inducer Fan 5 Minute Lockout
What Does Code A047_F Mean?
Code A047_F on the Rheem R802V is the alarm-level version of the inducer fan 5-minute lockout. Before the burners can light, the inducer (draft) motor must build enough negative pressure to close the inducer pressure switch, which proves the furnace is venting combustion gases safely. When the inducer cannot make that proof and the failure keeps happening, the Bluetooth Communicating IFC escalates from the low-severity troubleshooting code to this alarm code. In other words, A047_F means the problem is not clearing on its own.
Its milder counterpart is code-T047_F, the low-severity soft lockout that auto-retries once and often traces to a momentary gust or brief blockage. A047_F instead points to an ongoing restriction or a hardware fault. The homeowner-safe cause is a persistently blocked exhaust or intake termination outside, where ice, packed snow, debris, or insect and bird nests keep the inducer from building draft. The other likely causes are a failing inducer draft motor, a defective pressure switch, or a cracked pressure switch hose, all of which are pro-only.
A047_F is closely related to code-T045_F, which describes the specific condition where the low-stage inducer pressure switch fails to close after 60 seconds of inducer run. That is usually the underlying mechanism behind this alarm. Because A047_F signals a persistent venting problem, repeatedly resetting the furnace without fixing the cause simply repeats the lockout.
What You'll Notice
- Repeated 5-minute lockouts with no successful ignition
- The inducer/draft motor runs but the burners never stay lit
- The alphanumeric display flashes A047_F digit by digit
- A persistent blockage, ice, or nest at the outside vent termination, or the problem continuing after the weather clears
- Little or no heat over an extended period
Common Causes
| Cause | Likelihood | DIY? |
|---|---|---|
| Blocked exhaust vent pipe | Most common | ✓ DIY fix → |
| Failing inducer draft motor | Common | ✗ Call a pro → |
| Defective pressure switch | Common | ✗ Call a pro → |
How This Is Diagnosed
The outside vent and intake terminations are checked first, since a persistent blockage there is the homeowner-safe cause. If they are clear, a technician evaluates whether the inducer motor builds and holds adequate draft, inspects the pressure switch hose for cracks or restriction, and tests the switch, because a persistent A047_F usually means a hardware fault rather than weather.
How to Fix It: Clear the Outside Exhaust and Intake Vent Terminations
What You'll Need
Steps
- Turn off electrical power at the breaker or switch AND shut off the gas supply Flip the furnace circuit breaker to OFF, or use the dedicated power switch on or near the furnace, then turn the manual gas shutoff valve to OFF (handle perpendicular to the pipe). If you smell gas, leave immediately and call your gas company. Do not continue until the gas smell is gone.
- Find the vent and intake terminations outside Go outside and locate where the furnace vents through the wall or roof. Identify the exhaust termination and, if present, the separate combustion-air intake pipe, usually a pair of pipes or a concentric fitting.
- Inspect for ice, snow, nests, and debris Shine a flashlight into and around each termination. Because A047_F is persistent, look for a lasting restriction: packed snow or ice, a well-established insect or bird nest, or accumulated leaves and debris choking the opening.
- Clear visible obstructions from the outside only Wearing gloves, remove any visible debris, nests, snow, or ice you can reach by hand at the outside opening. Do not push tools deep into the pipe, and do not open or probe the inducer, pressure switch, or hoses inside the furnace; that work is for a technician.
- Restore power and gas and test over several cycles Turn the gas valve to ON and restore power. Set the thermostat to call for heat, then listen for the inducer to spin up, the pressure switch to click closed, and the burners to light. If it starts, watch several cycles to confirm A047_F does not return.
When to Call a Professional
Contact a licensed HVAC technician if:
- The outside vent and intake are clear but A047_F persists
- The inducer motor runs weakly, labored, noisily, or intermittently
- A pressure switch hose is cracked, loose, or disconnected
- The furnace never gets past the inducer stage to light the burners
- Any inducer motor, pressure switch, or hose work is needed
Frequently Asked Questions
How is A047_F different from T047_F?
Both describe the same 5-minute inducer lockout, but code-T047_F is the low-severity soft lockout that auto-retries and often traces to a passing gust or brief blockage. A047_F is the alarm-level, persistent version, which means the venting problem is not clearing and needs attention.
I cleared the vent and it still shows A047_F. Why?
If the outside terminations are truly clear, the draft failure is likely coming from a weak inducer motor, a defective pressure switch, or a cracked pressure switch hose. Those parts prove the furnace is venting safely, so they should be diagnosed and replaced by a technician.
Is it safe to keep resetting the furnace?
Repeatedly resetting a persistent A047_F does no good, because the control is blocking ignition until it can confirm the furnace vents properly. Until the underlying restriction or hardware fault is fixed, it will simply lock out again.
✓ Verified against manufacturer service manual — March 2026