Keeprite Mid Efficiency Furnace

[md.rtech]

Someone has installed a Keeprite furnace in my grandparents home a month back.  The furnace is a keeprite mid efficency 100,000 btu.  The home is 1200sqft attached raised bungalow.  The furnace is short cycling it is definetely oversized for this home.  Is their anything I can do to lower the btu rating of this furnace to a 75,000btu.  I was told I can change the burner orfices to the ones of a 75,000 btu but they may not be the same ones.  What are my options to fix this problem?
Furnace: Keeprite
model#: C8MPN100F14B2
serial#:A081445292

[Admin]

It's not a 2 stage furnace, so there's really nothing you can do, but replace the furnace.  You can't just lower the manifold pressure or change the orifices.  To achieve less BTU's you would have to remove a burner, a heat exchanger cell, relocate the flame sensor and install a smaller collector box.  Only the manufacturer can make these modifications, or the appliance would lose its certification.

Take a look at installing a 2 stage furnace if you decide to replace.