hot water heater exhaust tie-in with furnace


Old 09-17-00, 11:38 AM
Visiting Guest
Posts: n/a

I am moving my hot water heater from a closet upstairs into the basement. It isn't possible to go through the floor and hook up to the existing exhaust. Plumbing changes are messy but doable. The problem is the exhaust. Can I tie in the exhaust from the hot water heater (3") to the gas furnace exhaust (6")? Does anyone make a kit for this or is it a custom-made job? I can rig a connection if I have to, but would much prefer to use a kit.

Sponsored Links
Old 09-17-00, 08:28 PM
Sharp Advice's Avatar
Admin Emeritus
Join Date: Feb 1998
Location: The Shake and Bake State USA
Posts: 10,440
Received 5 Votes on 4 Posts
Thumbs down


To be possitive that there is no misunderstanding here, the answer to your question regarding tying in the water heater flu into the existing heater flu is NO!

This could become very dangerous. The reason being is the flu for each appliance is only large enough to handle that one appliance.

Therefore, connecting them together will overload the system when both appliance are exhausting and fumes will begin backing up. A serious situation since some of the fumes contain carbon monoxides.

My best suggestion is contact a licensed plummer. You need to get the advice of a professionial on the site to evaluate the system for a larger main flu.

Good Luck,

You might also try posting this question in the plumming forum. However, I suspect the answer would be exactly the same.
Old 10-05-00, 09:40 PM
Visiting Guest
Posts: n/a

hooking the water heater vent into the existing furnace vent might work. What determines this is the combined BTU imput of the the furnace and water heater, the verticle height of you chimney and the horizontal distance of your appliances from the chimney. The higher or longer your chimney, the BETTER it will vent. The closer your appliances are to the chimney and vented with the least amount of bends in the pipe, the better it will vent. Not knowing exactly your set-up would make it difficult to advise you if this would work or not. The best thing is to have a license natural gas technician see your situation. He or she can use the natural gas installation standards venting tables to see if this is doable.

[This message has been edited by sheetmet (edited October 06, 2000).]
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: