tankless water heater

[Randy West]

I inspected a home today that was extensively remodeled in 2013, with permits/inspections (I know- so what?). There is a Rheem 180,000 Btu tankless wh in a small laundry room. There was no combustion air, and the vent pipe is touching the wood ceiling. Is there a combo combustion/exhaust vent for tankless water heaters, and if so is it zero clearance to wood? Roof was not walkable, forgot to take a closer look at the vent pipe above the roof but it looked like a normal vent pipe. Second question- 3/4" pipe from home to water heater. But there is several feet of 1/2 inch flexible copper pipe at the propane tank. Is this allowed, or does it have to be 3/4" pipe all the way to the tank. I'm going to check Rheem website after I finish the report. but figured I'd get better (and easier) info here.
3195031951

[Scott Patterson]

I inspected a home today that was extensively remodeled in 2013, with permits/inspections (I know- so what?). There is a Rheem 180,000 Btu tankless wh in a small laundry room. There was no combustion air, and the vent pipe is touching the wood ceiling. Is there a combo combustion/exhaust vent for tankless water heaters, and if so is it zero clearance to wood? Roof was not walkable, forgot to take a closer look at the vent pipe above the roof but it looked like a normal vent pipe. Second question- 3/4" pipe from home to water heater. But there is several feet of 1/2 inch flexible copper pipe at the propane tank. Is this allowed, or does it have to be 3/4" pipe all the way to the tank. I'm going to check Rheem website after I finish the report. but figured I'd get better (and easier) info here.
3195031951

Randy, I'm pretty sure that unit is sold only by Home Depot.. I have come across the exact same unit before. It uses a concentric vent pipe(pulls in combustion air and exhaust flue gas). I'm pretty sure it needs a 1" clearance around the pipe.
This is a link to the install book.
http://www.homedepot.com/catalog/pdfImages/9f/9fddc9cb-8ce2-42ef-af79-92f282f25a2f.pdf

[Randy West]

Thanks, Scott, that is exactly what I was going to look for. It's not visible in my photo, but there is no tpr discharge line, so I had to recommend a plumber anyway.

[Dave Belisle]

Thanks, Scott, that is exactly what I was going to look for. It's not visible in my photo, but there is no tpr discharge line, so I had to recommend a plumber anyway.

most sealed combustion units with a concentric vent are zero clearance . There is a one inch clearance inside the pipe you see.