ratsandtats
Member
i work in maintenance in wv. our 8 unit navien tankless water heaters have a 10 inch air intake that i need to extend 3 - 5 feet as the original installer placed it at the top of an 8 foot pit with dryer exhaust coming from the bottom. the goal is to give the units more fresh air than they are currently getting to get a cleaner burn. the current plan (not mine) is to use a 10 inch straight fernco and just add a length of pipe. is this legal? i'm struggling finding out with any searches and since this isn't my primary trade i don't want to spend the money on the code book. thanks for any info.