I have A Confortmaker Central air and heat unit 50,000 BTU'S. I have 1900 SQ FT OF living space. From top to bottom, three of levels. I Finding that, When the temperature gets under 30 DEGREES, My Thermostat, doesn't reach above 68 Degrees on the second level and the third level, doesn't reach above 60. I'v tried everything, redirecting the heat by opening and closing certain vectors. Nothing seems to work.:confused:
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What part of the world do you live and what is the efficiency? What is the gas output pressure? My first guess would be you need a 75,000 BTU furnace.