Timberline Modification

[woodburner323]

Hello all, I recently inherited an old Timberline stove, and have a couple of questions for you regarding the setup and running of the stove, specifically the chimney/stove pipe section.

As is common with many older stoves, this Timberline has an 8" outlet on the back of the stove. The firebox is close to 2'x2'x2' in size. A chimney sweep came to inspect the existing chimney in my house (not used for many years), and gave me some bad news:

The chimney in my house is not fit to have a steel liner equipped, because the masonry is quite old, and it is also too close to the rafters/beams in the attic, thus creating a serous fire hazard. The solution to this issue is to install a double-wall pipe to insulate the chimney. However, it is against code in my area to reduce a chimney more than 1 inch below the outlet on the stove, and the maximum ID doublewall pipe that will fit in the chimney is 6". Therefore, running a pipe through the chimney is a no-go given the current situation. I'd have to install a new, separate chimney alongside the old one, and then probably remove the existing chimney from the roof and seal it to free the new pipe from obstruction. The chimney sweep told me that he honestly believed the stove would work fine with a 6" pipe, but it just isn't allowed.

So, this has got me to wondering; can I remove the current outlet from the stove, and weld in a smaller outlet from the firebox? That would make the stove a 6 or 7-inch outlet, and then it would match the chimney pipe. If I were to do this, would I have to modify other parts of the stove to accommodate the new airflow? I understand the risks that come with this sort of experimentation, and I intend to use the utmost precaution while setting up the stove. I understand that several of you will probably post warnings about CO poisoning, house fires, insurance refusing to pay for damages, etc., but please help me to discuss this hypothetically.

I searched online for awhile, and could not find much information about the airflow for these stoves, nor any information from people who have attempted similar projects....

Thanks,

Mike

 

[pen]

I feel your pain. My chimney was deteriorating, and was the minimum size for my 8in outlet fisher grandma bear. I didn't have the money at the time to install a new chimney, even though I loved that stove... So for about 500 I installed an insulated liner inside my existing chimney, for about 450 I bought a 1 year used Englander 30, and I sold my fisher for about 600.

In all, I'm thankful it worked out as it did. The 30 holds a fire and coals longer than the fisher did, and I burn 1 to 1.5 cord less of wood a year. Only caveat is where I could cheat a bit with the fisher if wood wasn't really well seasoned, the modern stove I have now really needs to see hardwood cut, split, stacked for drying for 1 year before going into the stove. The other gain I had is the chimney doesn't need sweeping as often, additional safety for the house, in all, I'm very happy it happened as it did.

My other reason for switching was because I had a hard time finding an insurance company that would cover me with such an old wood stove, as the fisher was. Even though it was solid and in great shape, it wasn't UL approved. To go along those lines, the insurance companies, even if they do allow for an older stove, often still require it to be installed to whatever the factory specified in the book at a minimum..... That said, even if you welded the smaller collar in, I'm afraid that wouldn't change the requirements for the chimney and could set you up for a problem in a worst case scenario, god forbid.

In all, if you really want to run this stove, I think you are wise to go the route of the full new chimney. Down the road though, should you choose to go to another wood stove, you'd also be looking at something that requires an 8inch chimney for best performance. Installing a stove with a 6 inch collar onto an 8 inch chimney is fine, but the draft isn't as good.

With that in mind, what sort of space are you heating sq ft wise? What is the house like in build? Where in NY? What are you heating goals? In all, I'd hate to see you spend the money on an 8 inch chimney to run this stove if it isn't going to fit the house well,,, then not be an ideal chimney for the next stove... just thinking ahead.

Best regards, welcome to the site,

pen

 

[woodburner323]

Hi pen, thanks for the response and explanation. I didn't realize that insurance companies will keep record of the make/model of the stove. I thought it was a generic thing someone would just check in a box, "House has wood stove, add $XX to premium."

I am hoping to use the stove to heat about 1800sqft. Hopefully not as a sole source of heat, but together with a forced hot air gas furnace. The stove seems to be a good size for the raw footage, but the construction of the rooms will probably make it so that one room is unbearably hot, and the others not so much. The room to have the stove is about 15x15 with 8ft ceilings, and 3 doorways - one is a large doorway that spills into another room of equal size, the other connects to a long galley kitchen, and the third goes into a small hallway/landing where there is a staircase, and more rooms on the other side.
I think I remember reading somewhere that the Timberline puts out around 35,000 BTU, it would probably keep those central rooms nice, and I would put the thermostat for the furnace in one of the further, colder rooms.

It's good to know that a newer stove might have such benefits as the ones you described. That said, I probably can't afford one easily at this time. The Timberline was given to me by a close friend who kept it for me until I could accommodate it in my house. I also sandblasted the entire thing and repainted it, also taking the time to painstakingly brush paint the doors with high-temp rustoleum, which I sprayed into a tray and mixed to create various colors. For those reasons together, I am hell-bent on using this stove. Although I see now that I really should have done some research before getting started....

However, I think the cost of materials for the chimney installation would be close to $2K. Then I would have to pull permits, etc. This is a tough decision. Maybe I can install a different stove, and keep the Timberline for my next house.