I know a model GMP furnace is a multi position unit, but does that mean it can be installed upside down (needs to be downflow)? Just checking before the installer does this...

If it is a multi pos furnace then odds are it can be horizontal or downflow

Read this

http://www.dnmech.com/lit/Good_GMP_SS186ce.pdf

read this

http://www.dnmech.com/lit/good_gmp_ss186ce.pdf

So just flip the whole thing upside down??

The factory instructions must be followed that come with the equipment. Combustible floors need special treatment etc. You also cannot install this in a mobile home or modular home if that is what you are doing since you posted very little information.

The factory instructions must be followed that come with the equipment. Combustible floors need special treatment etc. You also cannot install this in a mobile home or modular home if that is what you are doing since you posted very little information.

This is actually my dad's furnace that he bought for his house (not trailer or manufactured home) from a HVAC service man a few years ago that is no longer around or can be contacted. My dad can't find the installation instructions from the factory, and all I can find is the little bit of info online, which is the same info you gave me (quick link). Just making sure dad has what he needs for his house... Thanks

Here is a master service manual from Goodman that covers your model number. This manual is for quite a few different units so make sure you are looking at the right stuff for your unit.

http://www.hvacpartsshop.com/Gmph075-4%20Series.Pdf

Here is a master service manual from Goodman that covers your model number. This manual is for quite a few different units so make sure you are looking at the right stuff for your unit.

http://www.hvacpartsshop.com/Gmph075-4%20Series.Pdf

Thanks for your help!

No problem but make sure you save the above files on your computer since you might need them for service sooner or later.