Qty	Possible Causes:
2	Bad Inducer Motor
1	Water in Vent
4	Clogged drain line
	Water in Inducer
2	Improper Condensate Drainage
1	Bad Pressure Switch
	Water in Pressure Switch / Tubing

CHECKOUT:

1. Check Control Board

Start the furnace with a call for heat.
Ensure that power is present on "W" by checking for 24VAC between "W" and "C".
- No Power = No Call for Heat
- Power = The Inducer motor should start within 15 seconds.
  - Inducer Motor Starts → Step 2. Check Inducer
  - Inducer Motor Does Not Start + Code 3 ⇒ Check for 115V power to inducer.
    - Power + No Inducer → Step 2. Check Inducer
    - No Power = Bad Control Board

2. Check Inducer

Observe and listen to the inducer motor.
- Inducer motor runs normally → Step 3. Check Pressure Switches
- Inducer motor hums but does not start = Bad Inducer Motor/Capacitor or Item in Inducer ⇒ Remove inducer & check
- Sound of Water "Slurshing" = Water in Inducer ⇒ Remove Inducer, pour out water, re-install inducer → Step 4. Check Condensate Drainage
  - The only logical way for water to get into the inducer is by condensation over-running the rain gutter on the inducer outlet.
Listen for sounds of water in the vent piping (near the furnace and at the vent termination).
- If water is gurgling in the vent, look for low spots that will hold water.
  - The vent piping must have a constant slope back toward the furnace.

3. Check Pressure Switches

Ensure the drain and pressure switch hoses are in the proper location for the furnace orientation. (See attached file below)
Make sure there are no sags in the pressure switch hoses that could hold water.
Start the furnace with a call for heat.
Check Drain Switch (Low Pressure Switch)
- Switch Contacts
- With the wires attached to the switch, check for 24VAC between each terminal of the switch and Common.
  - 24VAC On Both Sides = Switch Closed → Check Vent Switch
  - 24VAC On One Side Only = Open Switch ⇒ Check Switch Pressure
- Switch Pressure
- Remove the Low Pressure Switch hose from the Collector Box.
  - Water Runs Out of Collector Box = Clogged Drain → Step 4. Check Condensate Drainage
- Connect a pressure meter to the Collector Box pressure port.
- Compare actual pressure to the pressure rating on the switch.
  - Pressure Near or Below Rating = Clogged Drain → Step 4. Check Condensate Drainage
    - Pressure Well Above the Rating + Open Switch = Bad Switch or Water in Switch
Check Vent Switch (High Pressure Switch)
- Switch Contacts
- With the wires attached to the switch, check for 24VAC between each terminal of the switch and Common.
  - 24VAC On Both Sides = Switch Closed
  - 24VAC On One Side Only = Open Switch ⇒ Use a pressure meter to check the pressure at the switch.
- Switch Pressure
- Remove the High Pressure Switch hose from the Inducer Motor.
- Connect a pressure meter to the Inducer Motor pressure port.
- Compare actual pressure to the pressure rating on the switch.
  - Pressure Near or Below Rating = Clogged or Restricted Vent
  - Pressure Well Above the Rating + Open Switch = Bad Switch or Water in Switch
  - Water in Switch is usually caused by a mis-run pressure switch hose.

4. Check Condensate Drainage

Check the rain gutter on the inducer outlet.
- Remove the drain hose and look into the coupling for any blockage.
- Make sure the drain hose is clear.
  - On horizontal runs, make sure the drain outlets are pointed slightly down-hill.
Check the drain hose from the collector box.
- Make sure all drain hoses are clear and have a downward slope.
- make sure the drain outlet is not blocked or clogged.
IMPORTANT! Make sure there is an "Air-Gap" in the PVC drain immediately upon exiting the furnace.
- Any trap after the furnace before the air gap will cause drainage issues.
- A tee running up to the air conditioner coil will act as an air gap.
In extreme cold conditions be cautious of Frozen Drains.