Error code reference

Lennox Heat Pump Error Code DS2:ON / DS1:ON

Circuit board failure - internal component failure on defrost control board.

SourceLennox XP16 Series Heat Pump - Service Manualp. 10

Diagnostic procedure

The full DS2:ON / DS1:ON 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

First diagnostic step

Cycle 24 volt power to board. If code does not clear, replace board.

SourceLennox XP16 Series Heat Pump - Service Manualp. 10

Unlock with pass

More steps, wiring diagram references, and verified part numbers

Includes expected resistance and voltage values, connector pinouts, and supersession notes for replacement parts.

Unlock DS2:ON / DS1:ON procedure $9.95

Or subscribe: $29/month for all codes plus Max diagnostics, with 70 Max messages a day. Plus applicable tax.

Where this code is documented

1 manual in the MyPros+ library documents this code for Lennox heat pump.

Models covered by the manuals that document this code

75,000+ service documents · 20,000+ error codes · 100+ brands

Get Started

$29/month · Cancel anytime · Or $9.95 3-day pass · Plus applicable tax

The full DS2:ON / DS1:ON procedure

Where this code is documented

Models covered by the manuals that document this code

Related Lennox heat pump error codes