Hearthstone Green Mt 60

[tabner]

@Mikedauby had a new gm60 on order a few weeks ago. Hopefully he'll provide some feedback after he gets it rolling.

 

[OffTheGridWannabe]

First thing make sure that draft is sufficient and not going negative. If the draft is weak, changing the stove won't necessarily fix the problem. This can be done with a manometer or Magnehelic.

Where in the house is the stove located? How tall is the flue system from stove to chimney cap?

I will add more details as I get them, but here is what I am up against. Hopefully this can all be improved:

- location... yes you guessed it basement
- chimney will get exact but ~25’ above grade
- liner in chimney 8” (likely single wall)
- stove pipe 6” to thimble has a 90 degree bend single wall (looks to be adjustable, which lets smoke through the joints and verified that fact)
- there were some gaps in stove pipe joints and with the exception of the bends in the 90 degree elbow I sealed them with Mill20 high temp cement.
- I have heard that there is another 90 degree in the chimney chase and THAT I need to get more info on any of at all can be corrected..

So with all that so far what are your thoughts. All is on the table. Even with the above I will add that it does throw good heat. Having used it of course now I can see what would really be enjoyable for stove. Such as N/S loading, door flange/lip for better sealing, lower inside deck for coals/ash. Then again I had not found this forum and I also have been so indoctrinated into the stove life.

Thanks

 

[OffTheGridWannabe]

First thing make sure that draft is sufficient and not going negative. If the draft is weak, changing the stove won't necessarily fix the problem. This can be done with a manometer or Magnehelic.

Where in the house is the stove located? How tall is the flue system from stove to chimney cap?

Thank you for the info on how to test the draft. I will do that. I am surprised that the installer would not check?
Question on flue/liner size. I would think that regardless of size (8” vs 6”) if there are draft issues one would have them with both liners sizes? Meaning if you had a 6” chimney liner draft would not improve if move to an 8” liner?
Thanks

 

[begreen]

Yes, it sounds like you are experiencing weak draft and potentially fighting negative pressure. The 6" to 8" jump is not helping. Is there a stainless liner in the chimney or clay? If clay, what is the ID?
Have you tried opening a nearby window an inch to see if this improves anything?

 

[tabner]

I will add more details as I get them, but here is what I am up against. Hopefully this can all be improved:

- location... yes you guessed it basement
- chimney will get exact but ~25’ above grade
- liner in chimney 8” (likely single wall)
- stove pipe 6” to thimble has a 90 degree bend single wall (looks to be adjustable, which lets smoke through the joints and verified that fact)
- there were some gaps in stove pipe joints and with the exception of the bends in the 90 degree elbow I sealed them with Mill20 high temp cement.
- I have heard that there is another 90 degree in the chimney chase and THAT I need to get more info on any of at all can be corrected..

So with all that so far what are your thoughts. All is on the table. Even with the above I will add that it does throw good heat. Having used it of course now I can see what would really be enjoyable for stove. Such as N/S loading, door flange/lip for better sealing, lower inside deck for coals/ash. Then again I had not found this forum and I also have been so indoctrinated into the stove life.

Thanks

does chimney go up the side of your house externally, or is it inside the house envelope?
and not sure how much it matters, begreen or someone more experienced can weigh in, but the manual for this stove says 6" ID chimney, or 8" square masonry tile, but it does not list 8"ID liner as a recommended option. (Although i can't think that would matter much, 7.5" inside square vs 8" Dia, are both about 56 sq in)

 

[OffTheGridWannabe]

Yes, it sounds like you are experiencing weak draft and potentially fighting negative pressure. The 6" to 8" jump is not helping. Is there a stainless liner in the chimney or clay? If clay, what is the ID?
Have you tried opening a nearby window an inch to see if this improves anything?

Chimney is a brick external chimney and the stove is tying into a (will confirm) single wall liner in the chimney. I need to test the open window approach. I have done that when initial burn, but not when steady burn for reloading, etc. where the smoking is happening.

 

[begreen]

If the liner is 8" single-wall uninsulated stainless then unfortunately it is not helping the situation. An insulated 6" liner will warm up quicker and draft more strongly.

 

[twier]

Hello begreen, I am utilizing larger splits. The bigger the better. Using 5-6 inch splits on top of hot coals, two of those and a smaller split to even things out. Your advise has been sound, thanks again! I am letting the splits catch a good edge burn and backing down the air almost closed, flue temp rises @ 100F after I close it down and settles in for hours. I have only done this a few times as I am trying to be close by to watch, learn and educate myself. No overnights as of yet. The stove does hold coals well though. I came down this morning after closing it down around 10PM, at 7AM was able to start a new fire with just throwing kindling on top. What a big difference this stove is from the older ones I am used to.

Dave

Different stove but I have a new Hearthstone Manchester. It does not have smoke problems and it works great. I wrote a review that should get posted soon.

 

[Strickly Anonomous]

I would like to talk with other owners of the new Hearthstone Green Mt 60 wood stoves.

We bought a GM60 last year and have had smoking problems the entire winter. We've been heating with wood for decades in the same location, and we understand about needing draft. Except for installing this new stove our stove-stove pipe-chimney set up has not changed.

Thanks for connecting.

I have purchased the GM 60 and like yourself. Nothing has changed from old to new with the exception of a new lined and insulated chimney. My old flue was 8 in diameter and the new and improved is now 6 in. And insulated. No pun intended this thing smokes like a chimney but inside the house. It's due for a one year inspection in about a week. They had better find something because I'm not happy with this set up. The door must remain cracked for a period of time to get her going. Unacceptable

 

[Strickly Anonomous]

I have purchased the GM 60 and like yourself. Nothing has changed from old to new with the exception of a new lined and insulated chimney. My old flue was 8 in diameter and the new and improved is now 6 in. And insulated. No pun intended this thing smokes like a chimney but inside the house. It's due for a one year inspection in about a week. They had better find something because I'm not happy with this set up. The door must remain cracked for a period of time to get her going. Unacceptable

The sad point is that it's a beautiful stove

 

[neverstop]

The CO issue sounds like it was caused by an oversized uninsulated liner and your house had a negative pressure situation. I have the sister stove the Shelburne that shares the same firebox. I have a 17.5' of 6" noninsulated liner in an external chimney with a rear exit, and have ran into negative pressure issues/smoke rollout.

If I don't crack a window on startup I have a really hard time preheating the chimney. If I crack it then it heats up much faster. I should install an oak.

I get smoke rollout when opening the door, my solution has been to only open the door to reload on coals. At least then no actual smoke comes out. I also believe the problem is with the baffle/air wash design as it doesn't improve even if the fire is raging when I open.

Once the fire is established it burns well. You need dry wood though. I've thrown some pieces in recently that were wet on the edges from rain and being on the edge of my wood stacks and it didn't not burn as well. Notably, the fire going out when I closed the door and needing to have the door cracked for longer to establish the fire.

On cold starts you need to make a top down fire with small splits laid down N/S under the wood stack to allow for the primary air to feed the fire. This change made a huge difference for me (begreen suggestion). I've also noticed that the closer you build the fire to the front of the firebox the quicker it takes off. So on cold starts or a small cold bed that would be the better approach.

My situation would probably improve with added chimney height and an insulated liner. However, I've also experienced the secondaries really firing with the primary 100% closed on a half load of wood.

 

[2zeroseven]

The sad point is that it's a beautiful stove

Yes it is. I've read this thread and others, but I can't really determine if people are generally happy with the GM line on balance. I don't know the sales numbers, but I presume plenty of people are happy/not posting here or elsewhere. But it does seem the people who experience problems don't have an easy time of it.

Interested in thoughts: Old center chimney Cape farmhouse. Has 6" stainless liner in the 200 yo masonry flue. Conservative estimate is 18' of pipe from the stove to the top (likely a bit more). Chimney runs through unheated attic, so the brick is cold for most of the run. (Don't know what the draft is, but never have a problem with the existing parlor stove - can run it with the door open or closed, and it starts no problem.) Plan to run the GM 60 or 80 (with larger pipe) more or less continuously thru the winter, so assuming it can hold a fire for 8-10 hours then hopefully won't struggle with cold starts too often.

As this will be our primary heat source, really want to get it right the first time. What do you all think?

 

[neverstop]

Yes it is. I've read this thread and others, but I can't really determine if people are generally happy with the GM line on balance. I don't know the sales numbers, but I presume plenty of people are happy/not posting here or elsewhere. But it does seem the people who experience problems don't have an easy time of it.

Interested in thoughts: Old center chimney Cape farmhouse. Has 6" stainless liner in the 200 yo masonry flue. Conservative estimate is 18' of pipe from the stove to the top (likely a bit more). Chimney runs through unheated attic, so the brick is cold for most of the run. (Don't know what the draft is, but never have a problem with the existing parlor stove - can run it with the door open or closed, and it starts no problem.) Plan to run the GM 60 or 80 (with larger pipe) more or less continuously thru the winter, so assuming it can hold a fire for 8-10 hours then hopefully won't struggle with cold starts too often.

As this will be our primary heat source, really want to get it right the first time. What do you all think?

Top or rear exit? Insulated liner? Have you had the chimney inspected? 200yrs old is.. old.

 

[cabinwarmer]

Good Day, just a quick response as I have posted several times around the GM60 and similar complaints previously. Please remember that a new EPA CAT Hybrid stove will not act anything like "my old stove". They are a completely different animal as far as operating them goes. I had many of the same issues my first 1/2 season. I have since learned and further understand this stove. I have a damper ready to install next time I clean the flue, I have too much pull (draft). From the owners manual -

"The recommended minimum chimney height is 14 feet (3 m) off the floor. The recommended maximum chimney height is 30 feet (9m).The Green Mountain 60 requires a draft between 0.08” and 0.15” water column. Ensure your chimney is long enough to provide the minimum draft, and use a damper if your installation has a required chimney height that provides too much draft."

The 0.08 - 0.15 is more then my previous cast iron baked enamel Upland stove. If your dealer has the time, the concern and/or the knowledge to measure your draft, that is where to start. Most dealers do not even care about this requirement. Most installers do not k ow what it means. I have grown to enjoy my GM60 greatly. I do a top down start every day. I do not open the door for the first 2 hours of the burn. I monitor the flue temp with a digital probe. When the top down settles in around 375-400 FFT, I load in the splits. Never a smoke issue. Load - sometimes I open the main, some time not, disengage the CAT, crack the door for 10 seconds and load. I will agree the glass on mine does get black over night as the stove dies out, or if I let it go low during the day burn. I clean it with wet newspaper and ash. There also was a recall from Hearthstone on the main air flow part. Seems the factory did not align some of the gasket material. My dealer never contacted me, I fired him and went to another dealer that supplied the part for free. The installation procedure is posted on the Hearthstone doc web page.

For those complains of smoke - is the smoke the same with the CAT engaged and not engaged?

 

[2zeroseven]

Top or rear exit? Insulated liner? Have you had the chimney inspected? 200yrs old is.. old.

The current parlor stove has rear exit, so there's an extra 90 that a Green Mountain replacement wouldn't have. I don't believe the liner is insulated, but if we go with the GM80 we would need to replace it anyway. Chimney was rebuilt from the roof up 20 years ago and was in good shape at that time (the Cape was built around 1760, but I think they may have replaced the chimney when they attached a Federal house to the Cape in 1830). There are only a couple feet total where the chimney bricks aren't in free air (where it goes thru the 1st floor ceiling and the roof). We'll have the sweep who installs review for safety of course.

 

[51221]

I have a GM60 and was having smoke roll out when adding wood on coals and on cold starts as well. I just added 3' to my chimney so it is now 15' straight up (4' single wall/ 11' double wall class A) and it seems to have really improved my smoke roll out when opening the door and establishing a fire from cold.

Other things I have noticed is if you're having trouble with smoldering fires you want a channel through the ashes from the primary inlet to the back of the stove, you want to make sure you have 4+ splits in the stove, and make sure your front most E-W split isn't laying against the primary air. A lot of the time a split laying in the back of the stove will smolder and if you bring it forward it will catch.

Overall if you have the stove already it can be made to function well. For those of you who are considering installing this stove if you have a less than optimal chimney setup (such as multiple bends or an increaser up to 8") maybe this isn't the stove.

Mine heats the house well, burns clean, holds coals overnight for a relight in the morning. It just needs more draft and dryer wood than a pre EPA stove.

 

[tabner]

Yes it is. I've read this thread and others, but I can't really determine if people are generally happy with the GM line on balance. I don't know the sales numbers, but I presume plenty of people are happy/not posting here or elsewhere. But it does seem the people who experience problems don't have an easy time of it.

Interested in thoughts: Old center chimney Cape farmhouse. Has 6" stainless liner in the 200 yo masonry flue. Conservative estimate is 18' of pipe from the stove to the top (likely a bit more). Chimney runs through unheated attic, so the brick is cold for most of the run. (Don't know what the draft is, but never have a problem with the existing parlor stove - can run it with the door open or closed, and it starts no problem.) Plan to run the GM 60 or 80 (with larger pipe) more or less continuously thru the winter, so assuming it can hold a fire for 8-10 hours then hopefully won't struggle with cold starts too often.

As this will be our primary heat source, really want to get it right the first time. What do you all think?

i am running the GM60 and overall it is a good stove for me. Little bit of smoke rollout if i am not careful with my reloads. and it requires a bit of attention when choking down the air to get it cruising well. For a serious house heater, being that i am heating from my basement, i kind of wish i went with a Blaze King, just for a bit simpler operation (i have two small kids and work full time, so it's a lot of juggling).
With that said, if your stove is on the main living floor where you can see it when you're lighting and adjusting it, or if you're home a lot, it could be a great stove. it's definitely a beautiful stove with impressive flame show.
I would recommend the GM80. They are a shallow firebox and the baffle hangs kinda low, it's hard to pack the box super full. plus you're farther north.