Well I actually have multiple questions. Last year I replaced my original late 50’s furnace with a 94% eff unit. I ran the intake and exhaust pvc pipes out the side of my basement to an under deck area. It’s a small rather confined space with a retaining wall on one side. Two sides of the deck are open but there is also a basement window directly next to where I had to run the pipes out so I continued the pipe under the deck to 8’ away from the basement wall. Not very attractive, and I’m not sure about the code implications, but it was a temporary solution until I remodeled the kitchen. Well I’m at this point now. The old furnace and dv gas water heater used to be combined into one 6” vent with a huge heat shield. I’d like to size that down to a 3” b-vent for the water heater and relocate it into a 6” stud wall(which I think is possible) and run my furnace intake/exhaust in the same wall and vent both out the roof. 1. Can I go with single wall vent on the water heater in the basement until I get to the floor penetration and then go with b-vent up through the floor. 2. I’m going to one floor then to the attic, do I need that sheet metal fire separation on the floor and ceiling of the first floor? Any other construction advice would be appreciated. 3. On the furnace pvc venting, is there any type of clearances required in the wall? This would work better if I can run it in an adjacent 2x4 wall. 4. On the roof penetrations, what are the requirements of the spacing with regard to each other on the dv 3”, pvc intake and pvc exhaust? I’d really appreciate any advice you guys have. I had found a picture representation of the pvc venting, but I can no longer find it.

Happy Holidays to everyone! Let me describe the problem I am having with my home furnance. Lately, usually at night for some reason, my home will be very cold, in the lower 60's. I will notice the air vents are blowing cold air. Brrrrrr So, I went to the garage and checked the furnace, the pilot light was on, but no burners. Hmmm..strange I turned heat off from the tstat, then turned it back on, burner lit and it was good to go. This has happened a few times in the last few weeks. I replaced the batteries in the tstat (LUX 500) and reset it, still nothing. Someone at work told me it could be the thermocoupler in the furnace, is this a possibility or does it sound something more major? The furnace is about 15 yrs old and a Carrier.