Venting propane water heater in basement through top of basement wall?

KYErik · Dec 31, 2015

I was offered a 4 month old propane water heater and since my electric water heater is getting old and I have a propane furnace in the basement, I was considering taking it IF I can avoid running the vent pipe through the first floor and out the roof.

First of all, has anyone converted from electric to propane water heat and had regrets?

Would it be safe to run the flue pipe out the top of the basement wall and then another 24" horizontally (once it is through the siding) to get it beyond the gutter/edge of the roof? Total horizontal distance would be less than 48".

Would I have to use 45 degree elbows to keep the cooling exhuast gasses moving upward?

Would the west or east side of the house be better for avoiding a possible downdraft (carbon monoxide) or would it not matter as long as the top of the flue was above the level of the peak of the roof?

I saw that they do sell draft assist fans for water heaters. Anyone have experience with one of these?

Deere Dude · Dec 31, 2015

It all depends on the style as to how it needs to be vented.

They cannot be near windows. 45s would be better than 90s but how would you go through the wall with 45s.

I love LP water heaters and wouldn't have an electric. Fast recovery. Running a gas water heater and gas stove for the last 8 years in Wisconsin generally cost $125 for gas for the year. Have gas furnace but used fireplace mostly.

robstaples · Dec 31, 2015

Does it have a fan built into it on the top of the heater? Or a traditional high exit gas temp heater? ( burner at bottom, straight up to a 3 inch exit) The fan models dilute the exit gas temp so you can use pvc to vent flue gas.
If it isn't a pvc vent model, I'd go price a new pvc model and see how much the free one is saving you. With installation and code issues, a free traditional type may not be worth it.

Water heat performance, you'll like gas better than electric.

davesl708 · Dec 31, 2015

You are going to need to comply with your local building codes on this project.
Install it wrong and you could have problems down the road. If you sell it could be a problem or if a fire starts insurance could decline to cover the damages.

Egon · Dec 31, 2015

davesl708 said:
You are going to need to comply with your local building codes on this project.
Install it wrong and you could have problems down the road. If you sell it could be a problem or if a fire starts insurance could decline to cover the damages.

Pay attention. This is what has to be met.

jfh28 · Dec 31, 2015

installation is going to depend on the type of gas hwh that it is.....condensing.....non-condensing.....high efficiency......since it is only 4 months old you should be able to easily obtain the installation manual online at the manufacturers website..........this will tell you the clearances required as well as the distances/elbows allowed.......keep in mind that horizontal is never really horizontal as there needs to be a pitch for when the gases condense so the condensate can run back down to the hwh....otherwise it will sit in the pipe and corrode it out in no time......the manual as well as local codes will tell you what is required.........I replaced an electric hwh with a tankless lp unit and would never go back to electric........operating cost is easily a third less as well as having an unending supply of hot water........Jack

mapper · Dec 31, 2015

Does your furnace have an double wall metal flue? If so you may be able to install a Y fitting in it and use it for both HW and furnace, that is the setup in my house. It was built this way by the contractor and passed inspection so I know it meets code in WA.

KYErik · Jan 1, 2016

No, the furnace is high efficiency and has a 2" PVC pipe vent through the top of the basement wall-it has a combustion blower.

joeyd · Jan 1, 2016

I don't know what your building codes would call for but as far as venting out the side here is a pic of the vents for my propane FAU which is in my basement. You can run them up to the floor joist space then out of the siding. The vents are to the right of the steps in the picture.

KYErik · Jan 1, 2016

joeyD-thanks for the pic- that's exactly what I'd like to do with my water heater flue. Does your propane furnace have a power draft or a combustion blower?

I'm leaning toward getting the heater and venting the flue through the basement wall using a draft inducer like this one (about $80) Tjernlund Blower, Draft Inducer DJ-3 | Zoro.com