Grandma Bear - New to Wood Stoves & Forum

[Read1t48]

Hi -

First off, I want to say "thanks" for all the great info. on this site. I've learned a lot already and look forward to learning more. My wife and I bought a house with a Fisher stove. Thanks to this site, and Coaly's info., the stove appears to be a Grandma Bear III. I am fairly new to wood stoves but I am sure enjoying the feeling of wood heat. We have had no issues with this unit and it seems to hold a fire and heat very well.

This fisher sits down in our basement. It is a stand alone unit, rear pipe, with 8" flue, lined with firebricks that are in good condition. We've been burning in it virtually everyday since the beginning of this month. Although the stove in our basement, it seems to be heating the house very well. My house is well insulated, which is a plus. I have enclosed a few pictures and here are my questions…

1. I have a chimney inspector coming next week to sweep my chimney and inspect the pipe connections. I don't have a thimble or a tee in the wall. The horizontal stove pipe just terminates inside the flue of the chimney. Is this okay? The wall, as you can see from the photo, is non-combustible block construction.

2. We have two flues in our chimney - one for a fireplace on our main floor, which has a propane gas log. The flues appear to be lined with clay tile, but no modern liner. I assume a ss liner would help reduce the possibility of a chimney fire, but would it also improve the efficiency of the Fisher stove?

3. We have considered replacing the propane gas log with a modern wood insert, such as an Avalon Large Flush, PE Summit, or something similar. A new insert would require a fairly flush stove as I only have 18" of hearth. Is there a big benefit to a modern stove vs. the Fisher? I like the simplicity of the Fisher and I'm not sure about cat stoves or some of the new designs which appear to have their own issues. Am I wrong?

Thanks for the feedback!

 

[vasten]

2. We have two flues in our chimney - one for a fireplace on our main floor, which has a propane gas log. The flues appear to be lined with clay tile, but no modern liner. I assume a ss liner would help reduce the possibility of a chimney fire, but would it also improve the efficiency of the Fisher stove?

To clarify you have three appliances a fisher stove in the basement, a fireplace on the main floor and a gas log system and only two flues in the chimney, is that accurate>
Or do you have another chimney also for the fisher stove?

 

[coaly]

To clarify you have three appliances a fisher stove in the basement, a fireplace on the main floor and a gas log system and only two flues in the chimney, is that accurate>
Or do you have another chimney also for the fisher stove?

"one for a fireplace on our main floor, which has a propane gas log"
That means the fireplace has a gas log set in it instead of burning wood. 2 appliances, but one of them sets in the fireplace. It could be an un-vented unit with damper closed or vented using the first flue. The picture looks like a vented unit with "glowing embers" over burner in the front. The Fisher is connected to the second flue.

Welcome to the Forum;
I'm not sure if a clay pipe or thimble is required since I've never seen a pipe cemented into a block chimney without one. Did you remove the pipe to see if there is one there? It's non-combustible but that may not be considered a direct connection ? The chimney pros here could tell you, or read over NFPA 211 for details on that.

An insulated liner would help since it would take a lot less heat to maintain the same draft. It is technically against code to reduce the pipe or flue smaller than the stove outlet, but your stove will physically work fine reduced. It would need to be 6 inch inside your 8. The double doors were designed with a larger outlet for open door burning with screen and in case they were connected to a larger flue in front of an existing fireplace. A 6 inch outlet would then allow flue gasses to expand so much in the larger flue there would be cooling, creosote and condensing problems. So the Fireplace Series is not as efficient as the Bear Series that use 6 inch. This thread has video of a double door connected to 6 inch with an added baffle installed with no smoke roll in problems. Post #28 below;
https://www.hearth.com/talk/threads/cant-seem-to-figure-out.119184/page-2#post-1617042

#3 question is going to get a variety of answers.
Legally it must be an EPA Certified Insert in your state.

You would have to add a hearth extension for something like a Fisher that sticks out. The advantage of that is a radiant portion that extends out of the hearth. In the case of electrical failure they heat well, and provide a place to humidify with kettle or cook. Unless you can find a glass door Fisher, fire viewing is only with doors open with screen in place.
A newer Insert is going to require a liner since I believe they all need a 6 inch flue.
They will burn cleaner once up to temperature during secondary combustion. The problem I've seen with that is the time duration of usable heat before reloading. I may be corrected, but the units I've burned put out enough heat as your only heat source a couple hours and when you loose secondary combustion, the glowing mass allows cool down to the point of needing to be reloaded until back up to temp when the secondaries kick in again. I need something that heats for 8 hours plus or the indoor temp falls. I get a lot larger temp variation with newer stoves but maybe I don't baby sit them often enough to keep them constant. Available wood has a lot to do with considering old or new. I have enough land to only cut standing dead that is ready to burn in a couple months in an older stove. Not sure if that would be good enough for a newer stove. I couldn't imagine getting three years ahead to dry fresh cut oak. It doesn't take much moisture in the new ones to cool the burn zone under baffle and loose secondary combustion.
If you have mostly soft woods there, someone will have to let you know what to expect from a newer stove burning what you have.
Just remember you're asking in the Fisher Forum where rabid stove fans are still looking for a cure.

 

[coaly]

I like the simplicity of the Fisher and I'm not sure about cat stoves or some of the new designs which appear to have their own issues. Am I wrong?

No, you're in the right place.

 

[Read1t48]

Thanks for the replies.

Vasten - Coaly was right on the assumptions. There are two flues; one of them services the Fisher and the other services the fire log which sits in an open fireplace on the main floor with the damper open.

Coaly -
I really like the Fisher, but with it being 8" and not overly efficient, I may need to consider a newer stove. I suppose the age old debate between cat. vs. non-cat will always exist, but it's hard to go from a simple Fisher -- to something more complex. I read threads about folks that watch their cat temp probe like clock-work and the temp on the stove to get things just right. That may work for some, but I'm not retired and it seems complex. Perhaps I'm over thinking it -- or they are I want something easy for me and the kids to operate. If I invest in a liner, it probably makes sense to put it on the main floor and look at some type of insert in place of the log. My chimney gets swept tomorrow so we'll see what they recommend.

I do know various mfgr's make some nice flush-style (what I would need without changing the hearth) that are non cat. My state doesn't appear to be "Fisher" friendly, but it looks like they may have some decent tax credits for qualifying stoves.

Thanks for the feedback.

 

[deal0704]

Hi Coaly,

I am new to wood stoves and while trying to research my Fisher stove I stumbled upon this site. It appears you have brought a wealth of knowledge to many people throughout the years on this site. I am very pleased to have found someone that can share some info about my stove and how to get the most out of it.

From what I have seen, it appears we have a Grandpa Bear stove. Pictures below. We bought the house this summer and I immediately was excited about the idea of having fires on our basement. I had a chimney sweep come clean it in the Fall to ensure we didn't burn the house down!

We typically use the stove only when we have time to enjoy it and will only have it running for roughly 6-12 hours. I have been having trouble getting my fire to take off without blowing on it ever couple minutes for the first 40 plus minutes. I usually start with some small starter sticks I buy from Kroger. I'll have a base log on one side with two small split logs resting on that over the starter sticks. I am not sure if my technique is lacking or if I am simply not getting enough Oxygen. I have heard that putting a grate in these stoves is a no-no.

I have also noticed a build up on the walls of the stove and wanted to know if that is the creosote I should be careful of and if I need to brush that out. The picture below shows my issue.

Besides all that, the main reason I was researching my stove was just to find out a bit of history about it. I think it is beautiful in our home! Other threads have been very informative about the history of these stoves. (Mainly through your information) I noticed some tags under the stove and have included the pictures below.

I greatly appreciate all your posts on this site and look forward to your response if you have the time.

Thank you!

Matt

 

[coaly]

Hi Matt and welcome to the Forum !
Don't worry about the build up inside the stove. That will remove easily or burn off when you get it burning correctly.
Probably nothing you're doing wrong, but tell us about your chimney. Masonry or metal, inside flue diameter and shape, height, and how many feet of connector pipe - elbows, cap with screen etc..... It sounds like your flue is not hot enough and those questions may answer it. Make sure there are no openings into the chimney like leaky or open clean out doors. You may also not have normal atmospheric air pressure in stove area. Make sure you don't have other appliances like oil or gas furnace, clothes dryer or radon fan exhausting to the outdoors mechanically from the same area. Cracking a window or door open to the stove area is the test giving it proper air pressure to the stove intakes.
When you get the chimney working correctly, I highly recommend installing a baffle to decrease smoke and get more heat from your stove.

If you wad up some newspaper in the back while your starting the fire, it will roar up the stack heating the flue. Close doors and open draft caps two turns or more. That will push much more air through the fire than blowing on it. Anytime you have the doors open working on a fire, or screen in place for fire viewing, it lets cooler indoor air above the fire rushing up the flue. This cools the flue with an excessive amount of air reducing draft. You have to use the chimney draft that is caused by hot rising gasses which allows atmospheric air pressure to push the air into stove. Doesn't sound or look like your chimney is doing that.
When you get enough draft, always burn on about an inch of ash on the bottom without elevating wood. Elevating on a grate gives it far too much air and is for fireplaces that need to burn that fast to heat a much larger flue.

If you read the Fisher Stove Story found in the Sticky section at top, you'll find when the fabricators across the country couldn't make them fast enough, Bob and Carol went to Kansas to sign a contract for Hesston to make the boxes in mass quantity. Your stove box is one of those.
I've seen the small black tag from Hesston with serial number, but not the other "Unit Identification" label. That must have been some of Hesston's numbers for stove or bottom part or what came on the material ?? Maybe something added by the fabricator or dealer who sold it? I assume it is a metallic type stick on tag that has survived all these years? If they are common, no one has mentioned them or sent me a picture or posted one.

The number for Grandma and Grandpa drawings start with 237. They are all 237-xxx. Each part has its own drawing. The bottom plate drawing being #237-166. The part number given at top of drawing for the Grandpa bottom plate is 500-GP. Addition of heat shields use the same stove parts and the stove becomes Grandpa II which was a listed stove. Are these tags on the bottom plate of stove or on a heat shield attached with machine screws? The shield number would be part number 520-GP. These numbers are not on any stove parts. They were only used for clarification within the company for engineers and fabricators. License owners or shop foreman would make a "cheat sheet" of cut sizes from the drawing for the builder / welder to make for each model. So the actual part number wasn't used on the shop floor, it was internal office use. None of those numbers correspond to anything I have from Fisher.