Questions on Discovery motorhome

Our AC/HP system works fine down into the high 30's. When the heat pump cannot keep up and the interior temperature drops 5 deg F below the set temp the propane furnace kicks in (this is an over simplification but close enough). I would expect that the Discovery has a similar setup if the units are Coleman Mach with RVComfort Thermostats. In any event the propane furnace sought to keep the water compartment from freezing in temps into the mid 20's below that I throw an incandescent worklight in the bay with a 100 W bulb, never had a freeze up.

Double check the Discovery owners web site and documents for more specific information about the coach.