Connecting Nest Thermostat for A/C & Heat

[bmals10]

Hello Forum,
Hello  @CoolingWizard (I see you have helped a number people out and thought I'd @ you 🙂 )

I am replacing the current thermostat on our main floor with a Nest.
The previous thermostat has 1 white wire & 1 red wire.  The red wire was connected to Rh and thermostat also had a "jumper" between Rh & Rc.

I connected the Nest.  White Wire to "W" & Red Wire to "Rh".

Nest connected however only detected heat.  I went through setup and chose Oil for Fuel and Radiator for Heat Type.

Is there a reason the Nest would NOT be picking up the A/C unit?  

* It is Winter in NY and A/C has not run for 8-10 weeks.
**I just moved into the house and this nest was used previously at my apt and did work for both Heat/AC but it was a single unit system, Gas & Forced Air - FYI

Thank You

[CoolingWizard]

@bmals10, 

if the current thermostat that you are replacing only has two wires, it does not have a wire for the air conditioner installed. The W wire is for heating but if you have an air conditioner, you would need a Y wire and a G wire.  
If your house doesn’t have an air conditioner, chances are, there’s a separate thermostat for the air conditioner from the heating system.

AC Cooling Wizard