We are installing a furnance temporarily while we finsih our basment and then run infloor heating on the main floor. I was wondering if you could use a flex gas line to connect the furnace to the main line? We are running a propane furnance.
Don't know what the code specifics are, but I did just that. The BI looked at it and said it worked for temp needs. I used black pipe from the furnace gas valve out about 6" to a shut off and a 90 to support the necessary downward bend and out to the main. If the temp furnace is out in the open, you might want to fasten it to the floor.