L
202
Moderate
Lennox · HVAC Systems (AC, Furnaces & Heat Pumps)
Pressure Switch Stuck Closed
Quick Answer
Error code 202 on your Lennox HVAC Systems (AC, Furnaces & Heat Pumps) means: Pressure Switch Stuck Closed. This is usually fixable — see the step-by-step guide below.
Likely Causes
  1. Pressure switch contacts welded in the closed position
  2. Water trapped in the pressure switch diaphragm
  3. Pressure switch hose connected to incorrect port
  4. Incorrect replacement pressure switch installed
How to Fix It
1
Disconnect the pressure switch hose and verify the switch contacts open using a multimeter
2
Check the hose for trapped water and drain if present
3
Verify the correct pressure switch part number for the specific furnace model
4
Replace the pressure switch if contacts remain closed without applied pressure
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Pressure switch
Pressure switch hose
Related Error Codes
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