RC-2000 Strange Behavior

[edge]

I installed the RC-2000 yesterday, replacing a conventional thermostat. I have a single stage carrier gas system, so the wiring is straight-forward.
Everything powers-up, it runs the AC fine when setup as auto-changeover, but.....when it calls for heat, the fan runs for about 10seconds, shuts off, then I hear the gas burners do their 45 second warmup, then the fan comes on again as it should.
The question is...why is the fan on before the burners warm up? All other thermostats call for heat, the burners warm up, then the fan runs for the specified 8 minutes or so.

Ideas? or do I have a bad unit?

 

[michelkenny]

Do you have your Omnistat set to call for fans when it calls for heat?

 

[edge]

Yes, it is set to run the fan when call for heat.

 

[michelkenny]

I would turn it off and see if everything works as you expect. By default the Omnistat does not call for fans when it calls for heat because I believe most furnaces will turn on the fans automatically once it is ready for heat. That is what my furnace does.

 

[edge]

Turned off 'fan on with heat' ............works like it should. Many thanks!