Proper way to vent water heaters and boiler together?

bipbap

Sorry if this isn’t Strictly Steam but this is the section I always get good advice in and it doesn’t connect with a steam boiler vent too…

What’s the proper way to route these vents for two water heaters and a gas steam boiler?

I know the water heaters tee should be a wye and the water heater vents should rise up higher before going horizontal, but should the wye just be swapped out in the same spot as the current tee or should each water heater have its own line and then wye in together a little further to the left of the heaters? Any other suggestions?

The right water heater rusted out badly on top after 8 years, maybe from condensation dripping back, so this was the motivator to reconfigure all this. Otherwise this setup had been fine for decades just as is.

EBEBRATT-Ed

If the water heaters could be vented into the chimney separately that would be better.

This is what is happening:

You set the water heaters at the same temp but in reality, most of the time only one runs.

The idle heater sits there , not cold but not firing so flue gas from the one firing condenses onto the idle heater. Also cool air comes in the idle heater draft hood and condenses on the idle heater when in contact with the warmer flue gas

bipbap

https://forum.heatinghelp.com/discussion/comment/1874595#Comment_1874595

Thanks for the thoughts on it. There isn’t really any easy way to vent them separately to the chimney. They have to pass through a hole in a rubble foundation and it’s more of a project than I can take on right now.

So if I can’t do that, what’s the next best option?

EBEBRATT-Ed

I would try avoiding running the flue from the farthest water heater over the other one.

I would run a separate flue from each WH and tee (a Y is better) them together as close to the chimney as possible then connect to the chimney with 1 pipe.

Check the pipe sizing.

Larry Weingarten

Hi, This thing in the water heater flue… is it open underneath? If so, it could be messing up the draft. Is there a reason for it being there?

Yours, Larry

EBEBRATT-Ed

@Larry Weingarten Good eyes, I missed that.