PEX Manifold to Water Heater Distance

[smsucigarguy]

I am confused about something I've seen mentioned in various products literature regarding the distance between a PEX manifold and a water heater. I have an alcove built into my laundry room that contains my water heater. The back wall of the alcove adjoins a kitchen pantry. I'd like to place the manifolds in the wall (with an access cover) behind the water heater, but am concerned that I am placing them too close to the water heater. The plan was to use 3/4" copper from the water heater to the manifolds (also copper). Is the 18" distance I've seen only apply to the length of the pipe connecting the two, and not the physical distance? Any help would be appreciated.

 

[jdgoodman]

pex manifold

The distance 18" you are seeing is developed length of piping not the actual distance from the water heater. You need 18" of metalic piping connected to your water heater before you transition to plastic.

 

[Sponsor]

 

[smsucigarguy]

Thanks. That is what I thought.

 

[hj]

manifold

More important than the distance from the heater to the manifold is the distance from the manifold to the faucets. The only rationale for using a manifold is to place it as close as possible to the majority of the faucets, regardless of how near, or far, that is from the heater.