Common venting multiple mod-cons? Which brands allow?

JohnNY

Not WM. Not Peerless. Not Lochinvar....

Of course you can with an engineered Exhausto system and the like, but I thought some manufacturers were coming around to allow for common venting of two or more boilers without outside mechanical assistance.

Am I dreaming?

wogpa67

You can on the Peerless 850 and up commercial units. But we never did it. I don't think it was cost effective.

Ironman

Bosch GreenStar, Buderus GB162, and I think Navien and TT when their racking system is used. But all of that is going from memory which is very good, but also getting very short.

The trick is that the controls can bring the fan on with each one without firing the burner until needed.

Henry

Lochinvar does allow common venting as the Crest is certified for Cat II. After 7 years of hard work, our B149.1-15 code allows common venting of Cat IV if the manufacturer has instructions on how to do it. Also only the same equipment of the same capacity can be common vented.

EBEBRATT-Ed

Not big on common venting. Maybe it can save a few bucks on some jobs, but may not be worth the potential problems.jmho

SWEI

Viessmann does. PM me if you want the docs -- I'm not sure they're on the website yet.

Triangle Tube only on 399's -- I spent weeks going back and forth with their engineers and Centrotherm trying to get approval for two 250's and a 110, but ultimately failed.

I would ask the venting manufacturers -- they keep pretty good track of who has approved what.

Snowmelt

Do u mean this

JohnNY

Well that's a mess, but yes, that's the general idea.

Snowmelt

There's more going on then just the water heaters, that's in a laundromat, drain pipes everywhere. But as long as you have the general idea.

Gordy

What's holding up the venting the appliances?

Mad Dog_2

Ha ha.....'its a mess Johnny! Mad Dog

Mad Dog_2

Gotta love those glued-on "cleanout" caps. Mad Dog

Rich_49

HTP allows on many units and even manufactures a few with multiple combustion assemblies with a common vent .

Sam81

That's navion tankless

JohnNY

OOoooh. Look at that! Nice.

RobG

Sam81 said:

That's navion tankless

It's actually "Navien" tankless.

RobG

Snowmelt said:

Do u mean this

It may not be your doing but why on earth would you have an upside down long sweep wye?

Abracadabra

RobG said:

Snowmelt said:

Do u mean this

It may not be your doing but why on earth would you have an upside down long sweep wye?

Heh.. because the guy that installed that won't ever have to worry about being underneath it when someone has to eventually open it.

Snowmelt

That's wasn't me I did the tankless only

Abracadabra

Snowmelt said:

That's wasn't me I did the tankless only

Yeah, I think (at least I hope so) that everyone knows that.