Another Fisher Wood Insert Question

Hello, I recently purchased a home in PA. In the unfinished basement, there is a double-door Fisher insert sitting on cinderblocks. The basement is nothing more than block walls, and a concrete floor. Directly above the stove going through the concrete block to one of two chimneys is an 8" terracotta thimble. the questions I have are as follows.:

- Can I use the insert just like I would a regular wood-burning stove? To be more clear, would there be an issue not having this in a hearth, and use it free standing?

-Can I just connect the stove to the thimble via some black pipe, or do I need a stainless liner? The current chimney is lined with clay tile.

-The chimney damper on the stove is broken, do I just get a piece of black pipe with a damper?

I know this isn't rocket science, but I do want my family to be safe while using this stove. I am new to wood-burning for heat. I just got a BK Sirocco insert for our upstairs masonry fireplace. I plan to use the Fisher to get the basement to temp. I will not be running it constantly, just to help get the BK insert on really cold days, or when we get to the house after it has been shut down for a while. Thank you all for your help in advance.

 

For me a pipe damper is necessary. One of those things that causes little to no harm but can be a savior if needed. They are cheap like under 10 bucks.

 

Agreed.

 

Depends on the chimney.

If the chimney is built to code, you can use it with the chimney as is. Most are not. Interior chimneys require 2 inches clearance to combustible framing members, exterior require 2 inch clearance. If it is not built to these specifications an insulated liner is required. That becomes a problem if the original flue is 8 x 8 and you're using an 8 inch appliance such as this since diameter reduction is no longer to code in PA, or most states adopting the International Building Codes.
This code also requires all appliances to be UL Listed, which this appliance was, but since many were before tags were used has no label. Only appliances with UL Label are now considered UL Listed. That is a requirement of the International Mechanical Code that governs sold fuel appliances and venting.

The damper is a chimney control that slows the velocity of rising gasses. This affects the stove by slowing the air coming into the stove. It is used for an over drafting chimney.

If you have the spark screen and are planning on using it with doors open in Fireplace Mode, a damper is needed. This becomes your only stove control with doors open. Close damper slowly until smoke rolls in at top. Slowly open to evacuate smoke, retaining some heat. They are not considered a radiant heater in Fireplace Mode.

 

Hi WeldrDave Warner Coaly,

I appreciate the responses and the knowledge! Pardon my late reply, I was not getting alerted that anyone was answering, and have been getting crushed at work and haven't been checking.
This is where I am at based on your suggestions:

The stove is already up on cinder blocks but is flush against a cinderblock exterior wall (I plan on pulling it off the wall about a foot or so). The basement is basically a concrete box. The only combustible materials are the floor joists and insulation in the ceiling. Metal Flanging? I think I know what you mean. I will take some pics and circle what I think it is if that's cool?

Inspector will be there tomorrow 12/16. I will also ask the technician for his advice for venting this thing if he tells me I am able. I will post his recommendations here to add to the knowledge base we already have. (If anyone thinks I should add the info elsewhere, please let me know).

Thanks again for the warm ( no pun intended) welcome, and your response. I was going to get rid of it and put a newer stove down there when we redo the basement. I have no idea when that will happen, and currently only have an electric ceiling-mounted heater down there. While up hunting this season only me and a buddy stayed at the house (definitely weren't cranking the heat), and our electric bill for the 4 days was $157. I know the Blaze King insert I got (got installed the last day of the hunting trip) will help on the main and second floor. The basement will still be a meat locker, and that ceiling heater is a resource hog. I will eventually put a new stove down there, but if I can use it now for the price of an inspection and some black pipe, I am in.

Thanks, Warner I Agree, If I can use the stove I will add one.

I mentioned it in my reply above, but I have an inspection of the entire chimney tomorrow, so I will see if is useable and to code. I will also check the stove for a label when I pull it off the wall. I will not use this stove if I have to make any modifications or add a liner. I don't want to invest that much time money into it. At that point, I can just use the electric ceiling heater.

I do not plan on using the spark screen for the Fireplace Mode. We do not hang out down there.

 

Coaly
Sorry to bring up a dead thread, but just one more question. The chimney seep said the chimney is to code and is lined with tile and in good condition. It is a
6x6 chimney. Considering the Fisher has and 8” flue, will there be a draft issue? Most of what I am reading dictates yes, but I have seen you drop a bunch of knowledge so I figured I’d ask you. Thanks again for the help and guidance here. This is extremely temporary maybe a season or 2 until I put a newer stove with a liner in the basement.

 

thanks dave! I appreciate the info, although I will not need the reducer. The clay thimble is a bit larger than 8" which will accommodate the pipe coming from the stove. The 6" concern stems from the chimney, basically the reduction is where the chimney meets the thimble. I do appreciate the assist though. I did have to buy an 8" fish stove adaptor to fit the 8" pipe coming out of the stove.
https://www.sandhillwholesale.com/images/Single_&_Double-Wall_Black_Pipe/21596.jpg

Also after doing some digging last night I found a post from Coaly in another forum which basically answers my question. There he states that the fisher stoves can operate on a reduced flue down to 6" round. The only time there could be an issue is if I try to use it in 'fireplace" mode with the doors open, and the spark screen in place. I have no intention of doing that so I think it will be ok. Heading up Friday night, gonna get everything joined Saturday morning, and will make a small test fire to test the stove. If it works awesome, if not, I'm out a few bucks on a stove adapter and black pipe. I'll keep ya'll posted.

 

Yes, a 6 x 6 flue is 36 square inch diameter. They work fine down to 6 inch round (when going straight up) which is 28.26.
The outlet being just under 50 works best on 7, which is 38.46, so you are close to optimum size there.

The difference is the larger the chimney, the more capacity. That is capacity of BTU it can carry. If you're not running wide open, with less BTU output, smaller is fine. There are charts that give height and diameter of flue that will give you the exact capacity total it can carry. It just limits the stove to that total BTU. Not a big deal since most stoves are never run to full capacity anyway. If you run about half all the time, you are better off smaller since you don't have that much heat loss to heat a larger flue.

Basement installs are notorious for negative pressure from other appliances exhausting out, stack effect when leaving basement door open for heat to rise in the house, dysfunctional family affairs (we all have them), so the stove and chimney gets the bad rap for not working properly.

 

I just looked at the report, it’s actually a 6.5x 6.5, but says it’s rectangle. So it’s bigger than I thought. Also, the chimney height is 25ft from the appliance.
I don’t plan on running this thing balls to the wall. It’s really to help the insert on the floor above it. Right now I’ll
I have to heat the basement is an electric ceiling mounted blower. As mentioned above that this thing is a total pig when it comes to kWh. Currently my basement is 38 degrees. I want to use the stove instead of the blower to bring the temp up while we are there. Doesn’t need to be 70 , I’ll take 55.
To offset the negative pressure, couldn’t I just crack a window in the basement to make up air?

 

Chances are your chimney liner is the nominal 8x8 size which measures 6 3/4 x 6 3/4. (Equivalent round is 7.4 uses 8 inch pipe)
Guess the only way you'll know is measuring the inner dimension yourself since they are calling it rectangular? 8 x 12 nominal would measure 6 1/2 x 10 1/2 inside.

15 feet gives you the same capacity as the Insert when figured at 50% efficiency. So 25 feet bumps capacity up from 210 at 15 feet to 250 at 25. That is 250 thousand btu per hour input rating. The input rating of chimney is twice the output of the stove with efficiency of 50%. Adding a baffle increases output, decreasing what chimney needs to carry. Smoke space square inch opening over baffle would be 44 square inches set for that chimney.

 

That's cold for a basement. Must not be totally buried? My rental next door is 44 with drive in garage, the rest buried.
Yes, you can crack a window for air if it needs it.

So far 3 rental homes I have bought in our area have not had the top of hollow block walls capped! It was customary to build a block wall basement and only put a sill plate partially over the holes. I break up styrofoam insulation scraps to drop in wall so they jam near the top and cap holes with mortar. Made a huge difference making the blocks hold air for insulating value. If the cores are open there is no dead air space in the wall. I fill any cracks and UGL dry lock the inside to stop any air leaks through porous block.

 

Not buried at all. Built on a slab. Thanks for the advice on insulating the blocks. The ceiling has insulation, but the beams are exposed. I will have to take a good look at the top of the block this weekend.
April will mark my first full year having the house. I have some wifi thermometers so I have an idea of what goes on in the house when I can’t be there temp wise. Also gives me a good idea of how to set the tstats while I’m away. This is the coldest I have seen it down there.
Thanks for the wealth of knowledge!

When connecting the black pipe to the thimble
It seems pretty snug, do I need to use furnace cement on the joints? Or any joints I am making for that matter?

 

No. Just push together tight and use three 1/2 inch long screws evenly spaced at each joint. They need to come apart for cleaning. Stove and gasket cement cracks and there is no sealant rated high enough for that application.

 

Coaly , you are the man! I’ll let you guys know how I make out with some pics. The fun part is gonna be moving this 400lb stove off the wall myself!

 

Well, finally got it up and running. Stove is coming up to temp, and has a nice strong draft.
Thank you to Coaly and WeldrDave and everyone else who offered guidance, and opinions.

 

Here are some pics.

 

So just a final update to close this thread.
This weekend we saw temps in the single digits. Before getting the stove lit, the basement was 42°. Upstairs I was running the BK insert full crank. And the temps were around 68.
Once the Fisher was going a few hours, the basement was 70° and upstairs with the basement door open was 72° . I was also able to turn the BK insert down a bunch. I will say this is a success!