Water heater / furnace shared venting?

[Greenmountain]

anyone know if a power direct vent furnace can share it's INTAKE vent with a power direct vent water heater? my furnace has a 3" PVC supply pipe (which reduces to 2.5" @ furnace). seems that would flow enough air for both...

 

[Master Plumber Mark]

it would probably be wise not to mix them

 

[Sponsor]

 

[Greenmountain]

my problem is that i live at a little over 9000' alt. only a few of the rheem pro models (http://www.rheem.com/product/reside...professional-classic-series-power-direct-vent) are certified for operation over 7000'. I will call rheem tomorrow to ask this, but wondering if i can switch to a smaller fuel orifice if I was to buy one of their lower altitude heaters (http://www.rheem.com/product/residential-gas-water-heaters-performance-series-power-vent). I believe the fan/blower is also different, so maybe not?

 

[MrStop]

In my research at buying a direct vent unit, I seem to recall reading that you cannot share venting with other equipment. In the unit I installed, it has a specific warning: "Do not install the heater into a common existing vent with any other appliance. This will cause flue gas spillage or heater malfunction, resulting in substantial property damage, severe personal injury, or death."

While I didn't have to solve for your altitude issue, here's a thread on my journey on buying a powered direct vent water heater: https://terrylove.com/forums/index....stion-powered-direct-vent-water-heater.59061/

 

[Master Plumber Mark]

it probably would be wise not to mix them.....and run a direct air intake from the outside to the
new water heater.... if you dont you will only have yourself to blame when you burn the unit out