Question About Installing A Duct Through The Chimney.

ID Flat Roof

Here's the deal, guys.

There's an old chimney on the roof I'm working at and instead of working around it i want to take the outside part apart, cover it up and install the roof vent. Right now the only thing that goes into chimney is the hot water heater duct, which gets somewhat hot when it's on. I'm thinking about putting a flexible aluminum duct through the chimney, connecting it to the heater and to the roof vent on the top of the roof. Can anybody tell me if this is legit? Is aluminum hose heat resistant enough or should i think about something more durable?

Thanks a lot for your help.

tgeb

No, you can't do this.

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Tom

www.gebcon.com

ID Flat Roof

what do you suggest I do?

BrianFox

get an hvac guy in there....

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naptown CR

What kind of chimney is it, Masonry B vent or what
If it is masonry you may be able to get away a stainless flue liner. the water heater should not be the only thing on that anyway particularly if the furnace ofr boiler was replaced and the wh was orpaned into the chimney.

ID Flat Roof

it is a one layer brick chimney that is not used for anything and the only thing integrated in it is the air duct from boiler

naptown CR

First post it was a water heater now a boiler. these are different animals.
Are the appliances gas or oil?

ID Flat Roof

sorry, water heater, of course
appliances are gas, but furnace is not integrated into the chimney

naptown CR

The water heater should have been removed at the same time I'll bet that chimney is in bad shape from the attic up and particularly on the roof.
You really have two choices
1 replace the water heater with a direct vent.
Run a B vent inside the old chimney and through the roof.
You will not be able to run aluminum and the alternative is a stainless liner however once this exits the chimney flue in the atic you may have to convert again to a b vent to go through the roof.
If the water heater is older than 7 or 8 years I would replace that it may be cheaper in the long run.
I would call the local JHA and see what they will let you do.

ID Flat Roof

Thanks a bunch

naptown CR

Always willing to help a solar bro out

wheeler

find another route

72chevy4x4

an electric HWH would circumvent venting issues.

RandyB1986

Why not tear down the brick chimney, eliminate it.....then install new deck over hole where chimney was. Then cut 6-8" hole and drop in a new B Vent pipe tieing it in below the roof line witht he existing pipe that is run out chimney..put a flashing unit around it and a storm collar and cap, seal it and call it done.

We have a lot of brick chimneys around here that use to be used for fuel oil furnaces...most of them are inactive since when people replace furnace they go with 90% gas now....which requires PVC pipe exhaust instead of metal or chimney.

The thing I hate the most is when the HVAC guys just stick b vent from gas water heater into the base of chimney in basement and dont run pipe all the way up the chimney, in this case...it is hard to drop in a new B vent section since you cant hook it up at the bottom inside the chimney, if that makes sense. In this case I would do like the other poster said and change water heater to electric


Good Luck to you.