flue pipes for hot water heater and furnace

[salv97]

does it matter which pipe is over the other pipe,my hot water heater flue pipe is under the furnace flue pipe venting thru the chimney,does that have to be switched so the higher pressure flue pipe of the water heater is above the furnace flue pipe,or does it really make any difference,thanks

[lynn comstock]

If you have any concerns I recommend seeing if there is a record of a permit on either appliance. Probably not. I then recommend buying a permit. The building inspector will verify the safety of your installation. Safety is more important than "free".

[rickboggs]

Here's the book
http://www.duravent.com/pdf/shbook.pdf

[REP]

Wye are you so confused,doesn't the smaller pipe go into the larger pipe?
The larger btu goes stright into the chimney and the smaller btu meets it at the corner,,,thats wye.

[George2]

Wye are you so confused,doesn't the smaller pipe go into the larger pipe?
The larger btu goes stright into the chimney and the smaller btu meets it at the corner,,,thats wye.

It sounds like they are talking about a brick chimney situation.

Yes, the W/H should be above the furnace vent.

Re-vent the furnace at the chimney putting in a wye and vent the W/H into it.

[salv97]

why exactly does the water heater flue pipe have to be over the furnace flue pipe

[George2]

why exactly does the water heater flue pipe have to be over the furnace flue pipe

It vents better and it's code.

[salv97]

ok it vents better,is there any issue with gasses from the water heater finding their way to the furnace thru the furnace flue,thanks

[eyeseeitall]

It would take a really strong downdraft in the chimney to push the water heater gases down, into the furnace vent connector and then into the furnace. It will only rarely happen- assuming the house isn't negatively pressurized by some other piece(s) of equipment...

[George2]

ok it vents better,is there any issue with gasses from the water heater finding their way to the furnace thru the furnace flue,thanks

I saw one case (on a wall furnace) were the furnace was vented above the W/H.

The furnace would not (always) vent properly.

[tinner73]

the OP is a DIYer...check his other threads. now he needs help. Ban him.

[Stamas]

Borderline.
But there are a lot of issues you can have. CO at the top. Have it checked by someone who knows how.

[lynn comstock]

the OP is a DIYer...check his other threads. now he needs help. Ban him.

It is dangerous to advise on flue piping. How do you know that the flue is located per code on the ceiling or is double wall where it needs to be or any other of a dozen subtle errors?

Let him call a pro. He probably has no desire to have his installation inspected as I suggested. Cest la vie.