Amana Error Code 3R: Pressure Switch Open

Severity
Warning
Type
digital display
Estimated repair cost: $75 — $200 (parts + labor)
Warning: Your Amana furnace has detected a problem with its pressure switch, which means it's likely shut down for safety and won't produce heat until it's fixed.

How to Fix Amana Code 3R

  1. Step 1: Check the furnace vent pipes (usually PVC) outside your home. Make sure they aren't blocked by snow, ice, leaves, or debris.
  2. Step 2: Ensure all registers and vents in your home are open and unobstructed. This helps maintain proper airflow throughout the system.
  3. Step 3: If the problem persists after checking the vents, it's best to call a qualified HVAC technician to diagnose and repair the issue.

How to Reset Amana Code 3R

  1. Turn off the furnace power switch, usually located on or near the unit.
  2. Turn off the circuit breaker for the furnace. Wait 30 seconds.
  3. Restore power at the breaker and flip the furnace switch back on.
  4. Set the thermostat to call for heat. If the error code returns after 2-3 ignition attempts, the fault requires repair.

Resetting clears the code from the display but does not fix the underlying fault. If the code returns after reset, proceed to the diagnostic steps above.

What Does Amana Error Code 3R Mean?

The '3R' error code on your Amana furnace indicates that the pressure switch opened unexpectedly during operation. This switch is a critical safety component that verifies the furnace's exhaust fan (inducer motor) is working correctly and venting combustion gases safely outside your home. When the furnace starts, the inducer motor creates a slight vacuum. The pressure switch senses this vacuum and closes, telling the furnace's control board it's safe to ignite the gas. If the switch opens unexpectedly during a heating cycle, the control board shuts down the furnace to prevent potential hazards like carbon monoxide buildup.

Common Causes

  • Blocked vent pipe (intake or exhaust) restricting airflow.
  • Failed or failing inducer motor not creating enough vacuum.
  • Defective pressure switch that is opening prematurely.
  • Loose or disconnected pressure switch tubing.
  • Condensation buildup in the pressure switch or tubing, especially during cold weather.

Diagnostic Steps

If... Check Expected
Furnace displays 3R error Visually inspect vent pipes for obvious obstructions or damage. Vents are clear and undamaged.
Vents appear clear With the furnace off, use a multimeter to check continuity across the pressure switch terminals. Should read closed (0 ohms).
Pressure switch reads open with furnace off Inspect the pressure switch tubing for kinks, cracks, or blockages. Tubing is clear and in good condition.
Tubing is clear Start a call for heat and measure the voltage to the inducer motor. Should read 120VAC during operation.

Applicable Amana Models

Replacement Parts

Part OEM Number Est. Cost Where to Buy
Pressure Switch — — —
Inducer Motor — — —
Pressure Switch Tubing — — —

Related Codes on Same Models

Other codes that affect the same Amana model families as 3R.

Code Description Severity
10R Communication Error Warning
1R Flame Without Call Critical
2R Pressure Switch Stuck Closed Warning
4R High Limit / Rollout Critical
5R Ignition Lockout Critical
6R Gas Valve Relay Fault Critical
7R Low Flame Signal Critical
8R Reversed Polarity Critical
9R Blower Motor Fault Warning