I have seperate heating and cooling systems ,can i control both with one programable thermostat?

Yes you can.

Most programmable thermostats will control bot systems.

You can but it will take some wiring. Depending on how each is controlled you'll have to engineer a solution. Just make sure the math adds up. Otherwise you can have more heat than you want (house fire).

Hope this helps.

'')

You can, but you will need to be careful about proper isolation of the 24 VAC wiring, perhaps with an extra relay or two (about $15 each). That way, the two systems don't have to "know" about each other, in terms of getting transformer phases correct, and whatnot.

I dont know much about this but I am sure you could.

After all you can control water temperature with one tap.

yes, but you'll need a professional to wire it properly. I have this