Question regarding my Venmar

[Bannerman]

Hi.  I have a Venmar HVAC in my house.  I also have a honeywell T87 thermostat that is next to the Venmar wall controller. I have electric baseboard heat with controllers on each baseboard so I am confused as to the purpose of the honeywell.  The only wires connected to it are green and yellow. At first, I thought maybe it was connected to an old security system that the previous owner had installed.   But I think it was hooked to the HVAC.  Could anybody tell me the purpose? I just don't want to remove something from the wall and regret it. 

For background, we are painting the house. So, since we are not using the security system, I am removing the hardware.  When I started taking apart the thermostat, I had doubts that it was related to the security system.  It has never controlled any heat or ac (we have a split air system) so I always questioned its purpose.

[NoDIY]

Can you check to see if the same two wires end up at the security system?

I have seen this years ago where a thermostat was wired to the security system. To monitor minimum temperature levels. For when you are away on vacation in the winter.