[THenne1713]

Furnace likely a SUBURBAN brand, but maybe ATWOOD? Thermostat (Might?) give a clue, but might just be Air cond brand, or aftermarket retro? REMOVE FURNACE RETURN to locate label? Steps likely KWIKEE brand, you will have to identify Model #, lay down, slide under, look UP for label? Maybe Cell camera helps? LOW BATTERY will shut off gas solenoid to furnace. Good luck