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Error code reference
Lennox Heat Pump Error Code DS2 ON / DS1 OFF
High pressure lockout: high pressure switch has tripped 5 times during a single Y1 demand.
SourceLennox XP14 Series Heat Pump - Full Service Manualp. 9
Diagnostic procedure
The full DS2 ON / DS1 OFF procedure
Step 1 is visible so you can confirm you are on the right page. The remaining steps, the ones that tell you whether to actually replace a part, unlock with any pass.
MyPros+ · DiagnosticsStep 1 preview
1
First diagnostic step
1) Remove any blockages or restrictions from coils and/or fans; check indoor and outdoor fan motor for proper current draws. 2) Check system charge using approach & subcooling temperatures. 3) Check system operating pressures and compare to unit charging charts. 4) Make sure all pressure switches and sensors have secure connections.
SourceLennox XP14 Series Heat Pump - Full Service Manualp. 9
More steps, wiring diagram references, and verified part numbers
Includes expected resistance and voltage values, connector pinouts, and supersession notes for replacement parts.
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