Oil Furnace and Wood Stove on Same Flue

[jpmako]

We are moving to our house in Maine after the new year. The current set-up is, in the basement an oil heater and our Cawley 600 wood stove share the same flue. Upstairs we have an older insert with a blower. Although the set-up in the basement is "Grandfathered", I know that this is not an ideal. Since we are moving to the house during the winter I have some questions regarding safe burning practices. Being that the house is vacant, we turned the heat to 55 degrees to save on heating oil. When we arrive I will obviously turn the heat up to make the house comfortable. Since we have a stove in the basement and an insert upstairs, I would like to primarily heat with wood.

My questions are:

1. Can I use the wood stove while the heat is turned on?
2. Should I worry about using the stove and oil heater simultaneously being that they share a common flue?

Thanks for any suggestions,
Jason

 

[TreeTangler]

Although it is done more than it should be, it carries the potential to be very dangerous to your family. Make sure your flue is clean and safe and check it often. Please make sure that your home is equipped with working smoke detectors and carbon monoxide detectors.

 

[jpmako]

Although it is done more than it should be, it carries the potential to be very dangerous to your family. Make sure your flue is clean and safe and check it often. Please make sure that your home is equipped with working smoke detectors and carbon monoxide detectors.

Thank you for the advice. I cleaned the chimney when I was there in the spring. I have also installed new smoke detectors as well as carbon monoxide detectors in the house. I know that this set-up is not in any way ideal but do you think it is safe to run the stove while the heat is on or will this be a problem? Next year I am going to have the chimney completely redone with two flues to remedy this situation. I am also planning on removing the insert upstairs and replacing with a Jotul F55 wood stove (separate chimney).

 

[shutup-n-cut]

I highly doubt that it is a legal installation but honestly that would be just a guess.
Local building codes also vary so what works in one place is no good in another.

 

[jpmako]

I highly doubt that it is a legal installation but honestly that would be just a guess.
Local building codes also vary so what works in one place is no good in another.

As far as I know this set-up was grandfathered and is legal.

 

[XSKIER]

As far as I know this set-up was grandfathered and is legal.

As long as your insurance is good to go, let her rip. No cents trying to reinvent the wheel.

 

[idahohay]

1. It is possible that both units would draft adequately.

2. Yes you should worry.

 

[shutup-n-cut]

Grandfathered in works. Probably be frowned upon doing it like that today.
If it ain't broke don't fix it.

 

[TreeTangler]

There really isn't a legal issue, you're not going to get fined for a setup like this. I'm really not sure who is "grandfathering" the setup. The issue is with the possibility for the flue not to draft one of the appliances or the chimney plugging and either one of these situations dumping toxic fumes into the house. As far as insurance goes, i have a hard time believing that they would be ok with it.

Either way, the choice is yours. Will it work? Chances are it'll work fine for heating as it is done a lot by folks who don't know any better. The problem with this setup that it drasticaly raises the chances that something can go wrong that would put you at risk.

 

[jwilly]

In Maine if the installation was in place prior to 1998 it is "grandfathered" 1999 and up it is not legal.

Oil fired appliances produce sulphuric acid in the exhaust and this can combine with the woodsmoke and create an extremely corrosive mix that can eat up the masonry joints in the chimney.

 

[Whitespider]

Oh boy... I've run multiple appliances, using multiple fuel sources, into a single brick 'n' mortar chimney all my life... and I'm still alive. Those "codes" are the result of a small percentage of simpletons that managed to burn their house down (or suffocate their family)... it's nothing more than government doin' the, "we're gonna' protect you from yourself" thing.

As long as you're willing to be aware, attentive and vigilant you'll be fine... lose the vigilance and you increase the chances of problems.
It's all a matter of taking responsibility... you're either aware, attentive and vigilant for yourself and family, or you are not and expect someone else to keep you safe. Life ain't safe, or fair... only you can make it into what you want it to be.

Is running multiple appliances, using multiple fuel sources, into a single flue the absolute safest way to do things?? Well... hell no it ain't‼
But it's a damn sight safer than drivin' to the local grocery store... just put it in perspective man.

 

[blackdogon57]

Vigilance would be getting something like that fixed before it burns your house down and kills you and your family. Carelessness would be letting it ride because by fluke it hasn't harmed anyone yet.

 

[Oliver1655]

Many are the houses I have been in over the years which have shared flues. A cook stove on one side of the wall & a wood/oil stove on the other side is one common arrangement. Another was having wood stove on one side & the propane hot water heater on the other side. How many of us have been in old farm houses with the snap-in flue covers on chimneys where some of the openings have been closed off? The key was they would have a hot fire to get enough heat to warm the drafty/poorly insulated houses & regularly clean the chimney.

Do I have a shared chimney? No. The way newer homes are setup/spread-out helps to eliminate shared chimneys.

 

[DavidBrown1212]

I run a wood stove and oil furnace into the same flue. I have my furnace set at 73 all the time. It only kicks on if my fire goes out. I have a cut off switch in the basement so the oil furnace can be cut off while i am building a fire and gsetting a draft started. Your furnace should have a little automatic draft control, which is the round flapper on the oil exhaust pipe. It has adjustable werights on it. It purpose is to maintain a constant draft pressure which helps keeps your oil furnace burning with right fuel/air mmixture when outside pressures may be fluctuating (windy nights). When you got a real ggood fire going, the fire will pull this flap open, reducing velocity and temp in the chimney, which may llead to more creasote condensating on your chimney. I put a rock on the flapper while the chimney is warming up, a good 2 hours, this does not completly solve the problem, but i feel it a good middle ground.

 

[Whitespider]

Vigilance would be getting something like that fixed...

Fixed?? It's only possible to fix something if it's broken in the first place.
It's been done that way for much longer than it ain't been done... and it don't present near the danger you've been led to believe.
I live in Iowa... I have a greater chance of getting bitten by a shark.

This house has stood for over 100 years with a shared flue... with as many as 4 appliances sharing it.
My gosh... how did people survive before all these safety codes to keep them safe?? Listening to some of you... we all should'a died before the age of three. It took me over two hours to remove or disable all the stupid "safety" crap on the last grass cuttin' machine I bought... in over 50 years of cuttin' grass I've never been injured. See, about the time I was in kindergarten, dad pointed at the spinning blades and told me not to put my fingers in there. About that same time he also taught me how to swim... took me out on the lake and tossed a float off one side of the boat, and me off the other... then he stood there with his arms crossed and watched me "learn"... ain't never once in my life wore a "life" preserver jacket, yet I'm still alive.

There's even a sticker under the hood of of my wife's van warning of moving parts with a picture some cartoon character getting chopped to bits.
C'mon... really?? Are people so stupid, so unwilling to take personal responsibility that there has to be a sticker like that?? Back in-the-day dad taught me not to touch the car brakes on a snowy morning until after you got moving... just slip it into gear with your foot off the brake. The reason was your brakes could take a set and make difficult to get moving 'cause they'd be dragging... but now the "safety police" insist every car have the shift lever locked in park until you step on the brake. Really?? Why?? Because some idiot backed through his garage door I have to pay for that ******** I don't want on every car I buy now.

It ain't the job of government to keep us safe from ourselves... the only thing that's been accomplished by the "safety police" is to raise a nation of mindless idiots and wusses. For some reason now-a-days people expect to be "safe" at all times... they somehow believe they have a "right" to be 100% safe at all times... and they somehow believe government and all those safety codes provide that. Every time some bumblin' idiot injures himself we have to have a new rule, law or code adding yet another worthless expense to our lives.

So I ain't buyin' that my flue needs to be "fixed"... but I can think of a lot of things that should be "fixed"...
And I sure in the hell ain't buyin' that a "safety" code somehow makes me "safe"...
If you feel better, if it helps you sleep at night to follow some arbitrary, one-size-fits-all "safety" code or rule... then by all means you should do so. But you have no "right" to expect me to believe as you do... and you have no "right" to judge me if I don't.
*

 

[DavidBrown1212]

I got my wood stove semi shrouded in sheet metal and the shroud ducted into the air handler, so you can have that heat distributed evenly.

 

[olyman]

ive been running the water heater, [gas], and my woodstove, in the same chimney for over 40 yrs.................think about this. yes,ng gases will cut the "creosote" coating off of the inside of the chimney during the summer. i then clean the chimney just before i start the wood burner.........then the chimney recoats itself during the winter...i burn dry wood only...and the buildup from the year before,,when i clean it in the fall,,near falls off........the inside of my chimney, is 10 inch. that will carry more than one "appliance"!!!!!!!!!!!!!!!!!!!!!!!!!

 

[AIM]

OK I have to ask. WHY should you not use the same chimney?? I have seen this comment a zillion times on here but never knew the why.
Don't just cite me codes. I could care less about the codes. I want to know the science behind the so called dangerous setup and why you shouldn't do it..

 

[Whitespider]

The inside of my chimney is 10×14... thats the equivalent of a 14 inch round pipe, or five 6 inch pipes.
There's a reason why that chimney was built like that... it was intended to be used with multiple appliances.
It is shared by a propane fired furnace, propane fired water heater and the wood furnace. I've never needed to clean it, the propane water heater exhaust causes all the "stuff" to flake off over the summer... and the draft is strong enough that most of that "stuff" flies out the top, very little falls to the bottom.

OK I have to ask. WHY...

There are several reasons for the code...

1. Sharing a chimney may reduce the draft to each appliance... but what if there's enough draft??
2. A second gas or oil appliance allows cool air into the chimney, which can cool the wood combustion gases promoting creosote formation... so why is a barometric damper allowed??
3. The combination of oil and wood soot forms a corrosive compound that can attack and weaken mortar... personally, I've never seen that happen, so I'm guessin' not all mortar is created equally??
4. Oil soot can ignite at a much lower temperature than creosote, thereby increasing the chance of a chimney fire... but, nothing can eliminate the chance of a chimney fire, can it??
5. Some gases release a lot of water during combustion (such as propane), which can also cool gases and promote creosote formation... but what if the chimney is warm enough, such as mine that runs up through the center of the house??

So yeah, the "code" is designed to protect the person who ain't smart enough to inspect and maintain his chimney... of course, before the code, most everybody was smart enough to inspect and maintain the chimney (personal responsibility). We have the code because some fool ignored his chimney, and because of him... we all pay. We are protected from ourselves.

Oh... I forgot to mention that a properly maintained and operating oil-fired appliance makes very little, if any soot deposits in a properly designed and operating chimney.
As with a lot of those "safety" codes, they address the "what if, worse-case"... they really don't do much to make us safer... they just protect the idiot from himself.
*

 

[Rburg44]

I run a wood stove and oil furnace into the same flue. I have my furnace set at 73 all the time. It only kicks on if my fire goes out. I have a cut off switch in the basement so the oil furnace can be cut off while i am building a fire and gsetting a draft started. Your furnace should have a little automatic draft control, which is the round flapper on the oil exhaust pipe. It has adjustable werights on it. It purpose is to maintain a constant draft pressure which helps keeps your oil furnace burning with right fuel/air mmixture when outside pressures may be fluctuating (windy nights). When you got a real ggood fire going, the fire will pull this flap open, reducing velocity and temp in the chimney, which may llead to more creasote condensating on your chimney. I put a rock on the flapper while the chimney is warming up, a good 2 hours, this does not completly solve the problem, but i feel it a good middle ground.

Can u give me a lil more info on this flapper thing this is my set up and would like to know more thanks