Why Use a 8Inch Flue Pipe on a VC Vigilant 1 W/ Coal Conver.

I have a '79 VC Vigilant wood stove with the coal conversion kit. Been using it for over 20 years. I do burn wood in the spring and fall. Like to burn coal instead. Pea size. The 8inch black pipe is 8feet tall before it enters a 8inch Metabestos chimney 10 feet. It extends 3 feet above the roof. What I've learn is that the large pipe was for a fire place viewing when wood was burned. What is happening is it's harder to get a good draft going when burning coal (nut) when the temps outside goes up to the 40's. Thinking to decrease the black pipe (needs to be replaced any way) to 6inch thus increasing the temperature which would increase the draft. Would the gasses interning the 8inch Metabestos chimney slow down? Like some opinions from the pros. Thanx George

I've read the same about the Vigilant I, that the 8" pie was for the added velocity and capacity for fireplace burning. The Vigilant II is 6" pipe, and not approved for wood burning. I'm not certain what diameter pipe the earlier version of the Vigilant II Multifuel uses. Hopefully someone will fill in that blank.

Under normal circumstances, going into an 8" chimney could possibly draw less than a 6" because of the lower flue gas temperatures in the warmer months as you've described. I wouldn't expect dropping the stove from 8 to 6" pipe would change that. Your chimney system is already 18' straight-up vertical feet. 3' above the roof is close to the minimum, depending on what structures are close by. Usually the easiest way to increase draft is to increase the height of the chimney buy 2-4 feet. It might be your cheapest and surest way to get better draft in the shoulder months.

Pictures of your chimney would help identify other factors. Are you using a barometric damper in the stove pipe (wouldn't recommend that on a Vigilant)?

The issue isn't the diameter, it's the height.

I don't remember the size stove pipe I had on my old Vigilant stove W/coal kit. I do know the Metal-Bestos chimney was, and still is 6 inch. How about the tear-drop shapes secondary air at the left side of stove. Is it closed? If open, it could slow draft.

Storm here. I am not using a barometric damper. The intake flap does not move on windy days. The secondary port is closed. I have not measured the draft with the menometer. Some times I have to burn a small log to get the chimney warm enough to establish a good draft. Once there it hums along at 425degrees for 8 hours. Installing a 3 foot higher chimney would work. ( if Metasbestos company is still in business). Thanks for responding. George pictures enclosed.

Very nice instal - looks good and right at home.

Judging from the picture of your chimney, it would draft better with another three or 4 feet of height. You're surrounded by trees and the nearby ridge line on the right of the picture. All of those obstacles could cause a problem in low draft situations.

I have an 80s multifuel which originally had an 8" flue, but I changed it to 6" because that's what was left behind by my Jotul woodstove. It's a center chimney of about 25 ft, and it draws very well! I can run the stove from 275* to 600* with very consistent results. Hope this helps...

Hi again Storm, Now that you have pictures to look at, I'm taking a second look. Your chimney is plenty above the roof but, over-all length is minimum. Yes, adding more chimney height may help, but I see other things to try as well. 1.)Less bends would help. What I'm getting at is; I think my Vigilant was top exhaust. If I remember correctly, the exhaust could go either way; top vent, or back vent. Maybe you can switch to top vent. If not, you should at least install a "T" in place of that elbow for easy cleaning of fly ash. 2.)Chimney cap. A lot of times they hinder the draft. A simple hat is better. Take a piece of sheet metal about 40" x 16". Fasten one end to the chimney, loop it up over the top, and fasten to the other side of chimney. The distance between the top of chimney, and top of loop should be about 8 inches. This will give you a simple, yet effective hat over your chimney. 3.)Yes, those trees will cause a lot of turbulence, which effects draft. Changing your stove pipe to 6 inch may, or may not help the draft. Depending on cost of fittings(reducers), changing to 6" may, or may not help the pocket book.

Storm here, well lots of ideals from the pros. I will think about changing the elbow. I need to anyway has small holes on the bottom side. I can move the stove back enough to clear the mantel which has shield on it to have a top exhaust w/elbow for cleaning. Presently I sweep from the roof then I take the black pipe out to the yard and sweep that. This way I get into the baffles behind the stove. The chimney cap that Oliver P says may work also. As with the 8 inch black pipe inside the house I will keep it for now. Going to a 6 inch may or may not increase draft. It's Vermont Castings thick pipe and still in good condition. Thanks for all of your replies Vigilpea Burner,Berlin,Rich W,Oliver Power. George

I run my old (83) VC with the insert and the 8"pipe, no problem. Couple of things to look at: Since you are burning both coal and wood, are you removing the insert for wood burning? For the gen I VC's to draw well they have to be sealed really well. You have to use stove cement on all of the seams of the insert when you put it back in, and you need to glue a gasket on the front of the lower lip of the front of the insert so that it seals against the doors when you close them. It is also important that you remove the air tube from the lower left hand (as you face the stove) side. You also need to make sure that the opening in the lower right side of the back plate is blocked off and sealed really well with cement or else the air will escape up the chimney rather than flowing through the coal bed. If all is sealed it should draw well with your setup.

Thanks Stonyloam, yes I 've done all what you have said. As with other responders to this thread, I will keep the 8inch pipe for now and increase the height of the chimney another 3 feet to see if the draft works better. Only change one thing so I can monitor it better. Today in Wisconsin it's -10 degrees draft is better. It's only when the outside temps go up to 30 or more that my draft get slow and heat temps of the stove barely reaches 350 degrees. I like 425 to 500 degrees 1800 sq foot open room plan cabin. Also I think I need to change out griddle and door gaskets. Next heating season will make these changes. Will keep you all posted. George