Omnistat 2

Just installed a new omnistat 2 (replaces a Honeywell thermostat); all connections are correct; setup is correct - multistage conventional (Trane 20xi)
 
When the thermostat is on cold - the AC blows heat
When the thermostat is on hot - the AC system blows heat
 
The original thermostat worked without any problems (changed to omnistat2 for humity settings)
 
Thank you for your help

Check you wiring on the Y1 and W1 terminals.  Make sure there are no shorts.
 
Disconnect the Y1 (cool) wire and see if the system runs at all when you have it in "cool" mode.  It shouldn't (except perhaps for the fan).  If it produces heat, that suggests that the thermostat is defective.
 
[Edit]:  I pointed to the Y1 and W1 wires above, but this may vary depending on the number of stages in your system, as @viroid mentions in his post.

How many stages?

On my Goodman heatpump(2 heat, 1 cool), Orange is energized when unit is in cooling mode, de-energized in heating mode, therefore White (aux heat?) is moved from W1 to W2.







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