lp
Moderate
Trane · HVAC Systems (AC, Furnaces & Heat Pumps)
Low Pressure Lockout
Quick Answer
Error code LP on your Trane HVAC Systems (AC, Furnaces & Heat Pumps) means: Low Pressure Lockout. This is usually fixable — see the step-by-step guide below.
Likely Causes
How to Fix It
1
Allow the system to sit idle for at least 30 minutes to equalize pressures
2
Check the evaporator coil for ice formation and thaw if frozen
3
Verify the air filter is clean and airflow across the evaporator is adequate
4
Connect refrigerant gauges to check suction pressure (should be above the low-pressure cutout)
5
A licensed HVAC technician with EPA 608 certification must perform leak detection and refrigerant charging
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
Refrigerant (R-410A)
Low-pressure switch
TXV or metering device
Leak repair materials
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