► There have been reported incidents where the 2-wire plug does not make good contact and causes the unit to run in heating mode when calling for cooling.

Qty	Possible Causes:
1	Loose Plug
	Mis-Wired Low Voltage
	Mis-Configured Thermostat
	Bad Stat Wire

CHECKOUT:

1. Check Low Voltage

Set the thermostat to call for Cooling.
At the outdoor unit, check for 24VAC between "O" and "C".
- No Power --> Step 2. Check Thermostat
When the unit starts, check the suction line temperature.
- Hot = Heating Mode

2. Check Thermostat

Re-Apply Power to the unit (if turned off from previous step).
- Compressor and Condenser Fan start and run normally --> Step 3. Check Refrigerant Pressures
- Compressor Does Not Try to Start = Control in Lockout, Bad Control Board or Bad Contactor
  - Check for 24VAC between each "Pressure Switch" terminal and "C" on the defrost board.
    - Power on one side but not the other = Open Hi or Lo Pressure Switch
    - Power on both sides = Pressure Safeties OK --> Reset control by disconnecting "R" and "Y" from the board then re-check.

3. Check Thermostat Wire

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Article ID: 291

Last updated: 25 Apr, 2017

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