Minimum height ceiling for 50-gallon water heater


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Old 04-22-21, 05:46 AM
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Minimum height ceiling for 50-gallon water heater

What is the minimum height ceiling for 50-gallon water heater? I only have a 7 foot height from floor to ceiling.
 
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Old 04-22-21, 06:13 AM
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Gas fired or electric? This makes a big difference. If electric you only need enough room to allow for inlet and out outlet of water. However, the important dimension will be the the flue (if gas fired). You must have enough room to have flue pipe inclined to rise into the chimney.

Most 50 gal heater will be about 50 inches in height. With a 7 foot ceiling (assuming this does not include the rafters), you'll have 34" to work with for inlet and outlet of water. Take away the rafter width and that leaves you at least 20" to work with. Plenty of room for all the piping.

But understand each brand of heater will vary in dimensions.
 
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Old 04-22-21, 07:25 AM
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Thanks. I’m looking at installing a gas water heater. We have code regulations where I am at that require an 18” water heater stand. There are a few different models of Rheem water heaters that I’m considering that come in tall and short models for the 50-gallon tank. If I use an 18” water heater stand, what’s the minimum clearance I need between the ceiling and the uppermost part of the tank assembly which I think is called the vent flue?
 
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Old 04-22-21, 07:48 AM
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Yes, that is the important thing. Will that still give you the room necessary to make the flue pipe inclined? 18" water heater stand seems excessive. If a flood condition situation should exist and 18" is what they recommend, then it seems to me at even 12'' flood condition it's too late to minimize any damage. I use to use a typical brick height to give me a bit of "flood" protection. But hey if that's code than that's code! If you can stand the extra diameter in terms of room I would go with the short boy as opposed to the tall boy. Much more flexibility with piping.
 
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Old 04-22-21, 08:56 AM
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Some jurisdictions require appliances with a flame to be mounted on a platform, usually in a garage and sometimes a basement. If gasoline leaks the vapors are heavier than air and hug the floor. Because of the mass of the vapors they can only build up so high. The raised platform hopefully holds the flame of the heater above the flammable mixture level of the fumes.
 
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Old 04-22-21, 01:22 PM
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I picked the first 50ga short Rheem I saw on HD's website and the top clearance it lists as 12" from the top of the water heater.



If you use regular galvanized vent piping, you need 6" clearance from the pipe, so you'll probably need more like 16-18" assuming an elbow coming off the top of the water heater.

You could use B-vent instead, which is double-walled vent pipe, and only requires 1" clearance. So you could probably get away with 12" or so clearance above the top of the water heater.
 
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Old 04-22-21, 03:19 PM
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Can the vent follow between the rafters or joists above to get to the outside wall?

If so then you could cut away the ceiling material and the joist bay would be used towards the overall height requirements.

Using the B style vent flue pipe it would be one inch below the subfloor above where it goes through the exterior wall.. Then allow the 1/4 inch per foot slope down to where the water heater sits.
 
 

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