I learned from this forum that a return “cannot be within 10 feet of the furnace” on a gas furnace. Is this ALWAYS the case? This return is at an adjacent wall, beside the door. Should this be called out?
Is the 10 foot rule also on Electric Furnace?
In this case yes, when furnace has an open grill.
Thanks Chris.
Just speculating, wouldn’t it be a defect, or at least unwise, to have the water heater so close to the furnace? It seems the furnace would be trying to steal combustion air from the water heater, but I’m no HVAC guy.
Not necessarily too close to furnace. But water heater has same 10 feet restrictions regarding the return air.
The ruling is 10 feet from any fuel fired appliance, unless the combustion chamber is sealed.
Okay, thank you Chris.
I’ll store that in my memory banks (the ones that did not burn out in the 70’s) 
Note I edited my comment a little after you quoted original.
In your photo it looks like the return opening is another room?
Yes, it’s in the adjacent room, but no door is installed. I was wondering if they installed a door if it may be compliant, even though it’s still within 10 feet.
I have the 2009 IBC but can’t find it.
If there was a door will it always be closed?
If its another room and the furnace is in a room with a closed door, its not a problem.
I don’t see how anyone could guarantee that. Heck, I can’t even get my kids to turn off tv’s or lights, no way would I rely on someone keeping a door closed!
