# Tankless Water Heater in Crawl Space?



## Plumber101 (Feb 25, 2009)

I wouldn't install in a crawl space.

They do make exterior mount systems unless freezing is an issue.


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## md2lgyk (Jan 6, 2009)

Thanks for the info. Unfortunately, freezing is very much an issue.

UPDATE: I contacted the manufacturer. They said crawl space installation is fine.


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## AllanJ (Nov 24, 2007)

Just be sure there is adequate oxygen supply, adequate ventilation of exhaust gases, and no danger of freezing down there.

Some models may use a concentric dual pipe through a wall to achieve the first two.


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## md2lgyk (Jan 6, 2009)

The model I have uses the concentric supply/vent arrangement. As for freezing, I certainly hope that's not an issue - all my plumbing is down there.


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## Michael Thomas (Jan 27, 2008)

A couple of thoughts:

1) Some manufacturers recommend/require a backdraft damper if you are installing in a freezing climate, this is especially important if there is only a short run to the exterior.

2) There's a lot of electronics and other assorted moisture sensitive componets in these heaters, if this crawlspace is "damp", I'd be leery of installing a tankless unit down there, in my Chicago climate I frequently see corroded equipment in crawl spaces, and it's often equipment such as conventional tank type water heaters much less sensitive than tankless units.

3) I've put together a webpage on my experience with tankless units (I like them, but they are intolerant of incorrect installation), you may find it useful: 

Tankless Water Heater Installation FAQ - Paragon Home Inspections Evanston / Chicago / Skokie / Wilmette / Morton Grove / Glenview / Northbrook / Illinois



___________________________________________
I’m paid to be suspicious…


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## md2lgyk (Jan 6, 2009)

Thanks for the link.


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