Lennox Error Code 2: Pressure Switch Stuck Closed
Warning: Your Lennox HVAC system has a pressure switch issue that requires professional repair.
LED Blink Pattern
LED blinks 2 times.
How to Fix Lennox Code 2
- Turn off your HVAC system at the thermostat and the circuit breaker to prevent further issues.
- Contact a professional Lennox technician to diagnose and repair the problem.
How to Reset Lennox Code 2
- Turn off the furnace power switch, usually located on or near the unit.
- Turn off the circuit breaker for the furnace. Wait 30 seconds.
- Restore power at the breaker and flip the furnace switch back on.
- 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 Lennox Error Code 2 Mean?
Error code 2 on your Lennox HVAC system indicates that the pressure switch is stuck closed. The pressure switch is a safety device that monitors the system's refrigerant pressure. When it's stuck closed, it can cause the system to over-pressurize, leading to potential damage and system lockout. This issue is common in Lennox systems due to dirt, debris, or faulty switch components.
Common Causes
- Dirt or debris blocking the switch
- Faulty pressure switch
- Kinked or blocked refrigerant line
Diagnostic Steps
| If... | Check | Expected |
|---|---|---|
| The system is locked out and won't run | Measure the pressure at the pressure switch using a manifold gauge set | Normal pressure for your system (consult Lennox manual) |
| The switch feels stuck when you try to move it | Inspect the switch for dirt or debris | A clean, functional switch that moves freely |
Applicable Lennox Models
- Lennox Healthy Climate(dual_fuel)
- Dave Lennox Signature Collection(gas)
- EL296(electric)
- EL296V(electric)
- ELP(electric)
- Elite Series(electric)
- G61(gas)
- Health Saver Series(electric)
- ML195(dual_fuel)
- ML199(gas)
- NCB(electric)
- NPE(electric)
- Pace Series(electric)
- SLO(gas)
- SLP(electric)
- SLP98(gas)
- SLP98V(gas)
- Slimline Series(electric)
Replacement Parts
| Part | OEM Number | Est. Cost | Where to Buy |
|---|---|---|---|
| Pressure Switch | 46-001530-00 | — | Find Part |
Related Codes on Same Models
Other codes that affect the same Lennox model families as 2.
| Code | Description | Severity |
|---|---|---|
| 1 | Ignition Failure | Warning |
| 3 | Pressure Switch Stuck Open | Warning |
| 4 | High Limit Switch Open | Warning |
| 5 | Flame Rollout Switch Open | Warning |
| 6 | Pressure Switch System Lockout | Warning |
| 7 | Ignition Lockout | Warning |
| 8 | Control Board Error | Warning |
| 9 | Line Voltage Polarity Incorrect | Warning |
| E250 | Lennox Code E250 - Indoor Blower Communication Error | Warning |