I've decided on our new Furnace and AC and have what I think is an excellent service company to install it. I was understanding the Rheem is "fully modulated", running from 30% to 100% in 5% increments. However, reading some of the brochures, how the furnace modulates may depend on the type of thermostat you have? Thus, the system may only function as a two or perhaps three stage unit? I don't have a model number. The quote only ID's a 100k btu Modulated Furnace. The brochure shows a "Classic 90 Plus Modulating Gas Furnace". Do I need to further clarify with the dealer what system I'm getting, or are all Rheem Modulating furnaces "FULLY" modulated when using a proper thermostat? Is there a particular thermostat I need to be sure I get? Thanks for your thoughts!!