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Heat Pump error codes
Search 3 Heat Pump diagnostic guides across 3 brands, or choose a manufacturer to narrow the database.
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3 guides found
LennoxHeat Pump
Code E121
Lennox communicator code E121 triggers when the outdoor unit low pressure switch detects unsafe refrigerant loss or freezing.
RheemHeat Pump
Code 22
Code 22 indicates thermal limit switch circuit opened to protect heat exchanger or electrical heating elements from thermal damage.
TraneHeat Pump
Code 2 Flashes
2 red flashes indicate system lockout due to multiple failed ignition attempts or loss of flame signal.