vent coal stove with oil furnace?

I have my oil furnace venting in maonary chimney (forced hot water system), can I vent a hand fired coal stove in same chimney? Coal stove pipe would be below furnace pipe, furnace pipe has baro damper.

Most building codes forbid hooking two appliances into one chimney. I'm sure its done regularly, but its not codeworthy.

You can use a power sidewall vent with the oil burner, the SWG units come to mind, and then use the existing chimney for the coal stove. The power vent would only have to run when the oil burner is on.

yes, you can, there is not much to worry about with that type of setup and i would not hesitate to do so, actually i vent a natural gas furnace, water heater, and coal stoker furnace in the same flue in my home. code doesn't like it, but the code was written primarily to address the concern of chimney fires in the sharing of wood burning appliances with others that allow the free flow of combustion air to creosote caused chimney fires; not a concern with coal of any kind. I would do link them together instead of powerventing either appliance, ignoring "code".

Highlander wrote:Most building codes forbid hooking two appliances into one chimney.

It's routinely done with a gas boiler/furnace and hot water heater combo. I know there are codes that require a certain diameter chimney with a certain sized flue outlet, but I don't know how it is handled when two appliances have the potential of exhausting at the same time into one chimney.

I know it allows the SAME type of fuel appliances as long as it sized correctly, but different fuels they don't like into the same chimneys. (gas, oil, coal, wood, etc..), I would think as long as your chimney can handle it if both are running together.

My sister has 2 furnances and hot water tank all into one chimney (all fuel oil), but they all go in to 12" diam chimney and they are are angled into the main pipe and up in size after each one, and they all have baro dampers.

Mixing of gas and oil appliances is allowed in the same flue subject to the correct sizing of the flue. The gas appliance must enter the chimney above the oil appliance. Solid fuel appliances, wood or coal, are not supposed to share a flue with any other appliance. Mostly for the reasons already stated in this thread.

Thanks for all the replys, The furnace does not go on from the themostat when my wood/coal burner is lit ,it heats the whole house (small cape, stove in basement) , just using furnace for hot water now so at times both are running at same time ,does not seem to be problem, my main concern was chimney fire because I do burn some wood. I drive around town and notice houses with one chimney with smoke coming out .... my guess is their doing same, don't know??!!? My furnace guy said I could direct vent furnace outside if I wanted to.

If you want them both in the one flue here is Burnham's info for doing it properly.

Two appliances running different fuels is not allowed by code.
I have my oil fired hot water heater, the oil fired hot air furnace and the coal stoker all venting into the same 6 X 6 chimney. I have checked the draft on the stove and it maintains the set point when the other appliances are firing. Bear in mind that I do not use the hot air furnace. The hot water heater running actually increases the draft in the chimney, the baro on the stove's smoke pipe rarely opens more then 1/4 of the way. With the water heater firing the damper will tend to open farther. I have had no problems with this installation. I always like to be careful with these kind of things so I have paid close attention to the operation of the equipment especially when I first did the install.
If I had a situation where there was no chimney available I would not hesitate to use a power or direct vent but I do prefer a masonry chimney.

So i'm curious if anyone out there is successfully venting according to the Burnham's method there. interesting. i am considering trying that out. I have one chimney with oil burner. both won't be firing at the same time... who knows though. i wouldn't want a house fire and the insurance to reject a claim because of that either.

Thanks coaledsweat and Wood nCoal

I would wonder about the draft setting of the baro damper. My oil boiler has the baro set pretty low -- if it's higher the excessive draft blows out the oil burner flame early in the burn cycle. My hand fired coal stove (not the same chimney) burns best with the baro set at .06 to .08. So you might have trouble finding a setting that works well for both.

I dont know what baro damper is set at? But it doesnt seem to affect when furnace is running.

Based on the pdf files attached by coaledsweat, what amount of draft does an oil furnace need and where do I take the reading? Also, do I need to take multiple readings, for example during oil burner operation and when its off?

Mark, the manual for your furnace should specify a draft reading and where it should be taken. If you don't have the manual, it may be available online. Unless otherwise instructed by the manual, you should take the reading with the burner running and the chimney warm.

My old Weil McLain calls for -0.05" of WC at the flue collar, and -0.02" overfire. Some newer appliances don't want any draft at all in the fire chamber...it all depends on how they are setup.