Chimney Flue Question...

Hi,

I have an existing oil furnace and considering a coal boiler or stoker furnace, I would like to know if I can tie into the existing flue with a Y-pipe or do I have to break into the flue in another location? If I have to make a new location should the coal be higher or lower than the oil duct?

Or can I NOT tie into the same flue at all?

Also, this flue has a Stainless Steel liner because of the clay flue was crumbling. This house was built in 1953 in CT and has a center chimney. The second flue is for a fireplace on the main floor, and I don't know if the second flue goes into the basement.

Anybody know If I can do this safely and legally?

Thanks

Normy

Hi Normy,

Most states (maybe all?) do not allow two devices in one chimney. What a lot of people do is use a power venter for the oil and the chimney for the coal.

Hi Freddy,

Dang, that's not I wanted to hear.

I don't think I can power vent the oil unless it goes 14 feet or so, it is a center chimney. If I can span 14 feet for oil power vent, can it run in a horizontal plane (in between basement ceiling joist). ceilings are lower than I would like.

If it is true I cannot run coal and oil in same flue, than can I disconnect the oil furnace for the cold months and tie everything into the coal boiler? That would mean running the 3 circulators and everything that is required to make the whole system work.

Please note that I do not have any plumbing heating experience at all and this is quite a new topic for me to grasp at this moment.

Thanks

Normy

you can run different fuels in the same flue, the ruling was not designed with coal in mind. I run three appliances in the same flue on my home and wouldn't hesitate to advise someone else to do the same. it's not a question of safety, but a question of draft you will want to make sure that your chimney can pull decent draft .04 minimum on both appliances and you will be fine if it's a stoker, more draft for hand- fired.

firing appliances using different fuels (even wood) on the same flue is very very common. even on many new "professional" installs; this is not really a safety issue to lose sleep over, it's important to advise people on what code allows, however, understading the thought process behind the code and why it was written a certain way is more practical.

HI Berlin,

Is there an easy way to check for draft?

If what your saying is correct, can I use a Y-pipe into the same oil duct or should it be broke into higher or lower than the oil?

Thanks for the reply!

Normy

The most important concern is if your building codes say not to share the chimney, then your insurance company may not cover a loss if it has anything to do with thechimney.

Many chimneys are capable of handling the needed draft for several devices.. you need to buy a Manometer to measure your draft.. A Dwyer Model 25 MarkII is the model with the correct scale range.

The best way to hook up your system would be to powervent the oil boiler, since it will be running very rarely if at all. If you must share the chimney with te coal boiler, get an eletronic draft damper for the oil boiler,, it will close off the draft pulling air through the oil boiler, and therefore the heat loss going up the chimney.

Member Coaledsweat has posted a .pdf file of the recomennded methods to share a chimney. You might try PM'ing him for the info.

Greg L

Normy wrote:Anybody know If I can do this safely and legally?

Yes and no.

Here you go, I seem to have lost the attachment but I found a link to where I posted it previously.

Post by coaledsweat - Is the Dealer's Venting Advice Correct?

Is there a length issue for using power vents and oil furnace? And can it be run in a horizontal plane?

Thanks

Normy

Here's a chart from http://www.fieldcontrols.com/. With the proper model you can vent horizontally quite a distance, but it might get expensive as you'll need probably "metalbestus" type pipe to get clearance.

Always check with your local code enforcement office and get it inspected.
I think a standard rule is one appliance per flue.
Many insurance companies also incude a list of "gotcha's" in the fine print more to come I am sure with everyone getting hit with high oil prices.