Bob,
I wonder if the temperatures close to the furnace may be too high for the bubble wrap insulation.
We have the same issue, very little heat comes out the registers. Then the heat exchanger gets too hot and the hi-limit switch kicks out till it
cools. The furnace cycles many times before it gets the place warm. There were no obstructions through the hoses, just too much turbulence.
A couple years ago in the fall while shivering, I opened the front of our Suburban 30K BTU furnace and left the cupboard door open. Wow the heat that
came out was awesome. So much heat that the thermostat lags the temperature so I need to turn it down manually. I've left it like that since. The
blower has enough force to open the door, when then closes under gravity when the furnace shuts down.
I'd be interested to hear how you make out. I was thinking of making a duct from the front to back.
--
Bruce Hislop
ON Canada
77PB, 455 Dick P. rebuilt, DynamicEFI EBL EFI & ESC.
Hubler 1 ton front end
http://www.gmcmhphotos.com/photos/showphoto.php?photo=29001
My Staff says I never listen to them, or something like that