Green Mountain 40 Not Working

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
  • Super Cedar firestarters 30% discount Use code Hearth2024 Click here

labans

Member
Dec 31, 2020
18
Central Texas
Last January (2020) we purchased a Green Mountain 40 . We live in Central Texas where we are lucky to have more than 20 days a year when we can fire up the stove. We have been in the same home for 36 years and for the last 30 we have had a Vermont Castings Seneca stove which worked 100% all of the time. Never failed to start a roaring fire quickly, never smoked. When we decided to buy a new stove, we merely removed the old stove and installed the new one—same chimney, same size everything, same location—just new stove.
From day 1 we could not get the stove to light and burn. No draft and when the fuel was lit smoke poured out of the front of the stove requiring the fast closing of the door which promptly put out the fire. The seller had no answer. I found out that there was a recall on the stove, as it was brand new, so I called the seller who promptly ordered the new part and we installed it. It was a revised air inlet. However, no change at all, still cannot get stove started without filling the house with smoke no matter what.
What have we done to deal with the issue?
• 100% assured that we have perfectly dry and excellent quality Oak wood; also tried Fat Wood (burns wildly until door is closed)
• Attempted to start the stove using the “teepee” method
• Assured NO chimney blockage and NO creosote build up
• Opened all doors and windows when attempting to start the stove
• Provided a powerful fan pointing directly at the air intake of the stove when attempting to start a fire (failure)
• Checked the specs on the chimney height: Verified 37” ABOVE the peak of the roof—total length is 22'
• Tried “heating’ the chimney pipe by burning a large amount of paper—does not work because once door is closed, the fire is snuffed

Upon startup the stove begins to smoke immediately and one has to close the door extremely fast, but smoke still escapes.
But even worse is that when the door is closed, it snuffs the fire out EVERY TIME. This is even when using fat wood or fire starters!!!
Then if I open the door even the width of a sheet of paper, the flame will begin, but SMOKE will exit and fill the room. Close the door to stop the smoke and the fire is SNUFFED.
Yesterday I went to the top of the chimney and removed the cap. I then ran a professional chimney pipe cleaner brush which loosened ash from the pipe—minute, minuscule particles. I made sure that the bypass door of the stove was wide open and the air control wide open. Doors of the house were also opened. I then shined a very powerful LED light down the pipe. NO AIR was moving in the pipe which was verified by seeing the loosened ash particles just floating in the pipe, when they should have been hauling-butt out the top of the pipe.

Can anyone come up with an idea on what is wrong? I have been using wood stoves for over 60 years and have never encountered such an issue.
 
Welcome. It sounds like something may have changed in the home that is affecting the stove. Did any major changes occur between having the Seneca and the new stove? Changes would be things like sealing and tightening up. HVAC changes, exhaust fan addition, attic fan addition, etc.

Can you describe the flue system in detail from stove top to chimney cap? Is this an all metal, 6" system or is it connected to a masonry chimney system?

I have been using wood stoves for over 60 years
Dang, that's a long time. You make me sound young.
 
Thank you for the reply.
We removed the Seneca and installed the GM40 in about 2 hours and attempted to fire it up the next day. After many attempts I called someone at Hearthstone who told me they had a recall on the air intake vent which is why I could not start the stove. They sent a new one, I installed it and could not notice any difference.
No changes to the house in any way.
Starting at the stove, the first 4 feet are single wall 6" pipe that then connects into a double-wall insulated stainless steel pipe that runs 18' to terminate at 37" above the highest point on the roof. It has an open-type cap on top with ample air flow.
The pipe goes through a ceiling with proper safety components and after another 8' goes through the roof, similarly. Both are wood construction; the roof has asphalt tiles.
 
Hi there, I'm using a GM40 on a chimney just a few feet longer than yours (mine's around 25').

I have had quite the opposite experience so something is wrong... I hope we can help you get things figured out!

There were similar early reports of "snuffing out" when the door was closed. At first I thought this could be EPA-stove-first-timers with poor quality (wet) wood (not your case, although oak needs a lot of time to dry and a lot of heat to get burning well... but you know that... I assume yours has been split and stacked under cover for a few years before burning? Gotta ask...).

Then there was a fellow who had the air intake under the stove blocked by the ID plate. Yep, that would snuff things out right quick after closing the door. Have you double checked that? (You say you pointed a fan at the air intake so I assume "yes".)

This:
...also tried Fat Wood (burns wildly until door is closed)...
makes me think it's an air intake blockage, or possible pressure issue as Begreen is surmising...

Don't despair, there are a few of us GM users who are very happy. In fact, I had to put a damper in mine because it was drafting too hard, producing directly opposite results as you! So pop us some answers and hopefully we can find a culprit here.
 
It almost sounds like the air intake is blocked. I'm curious what the air intake recall consisted of. Can you describe what part you replaced? Wondering if it's related to the secondary or primary air intake. I attacked a parts diagram for the stove too, in case it's helpful.
 

Attachments

It almost sounds like the air intake is blocked. I'm curious what the air intake recall consisted of. Can you describe what part you replaced? Wondering if it's related to the secondary or primary air intake. I attacked a parts diagram for the stove too, in case it's helpful.

I believe that the part replaced by the manufacturer was #38, Pipe:LPAO
I cannot tell from the diagrams if the air intake is blocked---when I look at the 4" intake hole on the bottom of the stove I can see that there is a metal shield that is bright metal, not black like all the rest, that covers over 3/4 of the hole. It does not look like it is cutting off the air, but it sure as hell is restricting the in-going air.
I am attaching two photos, first one shows the intake with the shutter open and the other with the shutter closed. Maybe that bright piece of metal should not be there!!!
 

Attachments

  • [Hearth.com] Green Mountain 40 Not Working
    IMG_2738.webp
    96.7 KB · Views: 392
  • [Hearth.com] Green Mountain 40 Not Working
    IMG_2739.webp
    87.2 KB · Views: 446
I do not think it should be there. I do not have that shiny piece on my stove. We can see what @Nigel459 says. Also, when you close the air intake, I can see the intake damper behind the shiny piece, so I don't think the shiny metal is part of your air control. It almost looks like a piece of extra flashing left in there from packaging or assembly or something.
 
Thank you for the reply.
We removed the Seneca and installed the GM40 in about 2 hours and attempted to fire it up the next day. After many attempts I called someone at Hearthstone who told me they had a recall on the air intake vent which is why I could not start the stove. They sent a new one, I installed it and could not notice any difference.
No changes to the house in any way.
Starting at the stove, the first 4 feet are single wall 6" pipe that then connects into a double-wall insulated stainless steel pipe that runs 18' to terminate at 37" above the highest point on the roof. It has an open-type cap on top with ample air flow.
The pipe goes through a ceiling with proper safety components and after another 8' goes through the roof, similarly. Both are wood construction; the roof has asphalt tiles.


Soooo? Are you saying you have a straight up and out vent system? 4 feet of connector pipe seems short? Or is the stove on a tall hearth? It sounds like it but figured I'd confirm.
 
I do not think it should be there. I do not have that shiny piece on my stove. We can see what @Nigel459 says. Also, when you close the air intake, I can see the intake damper behind the shiny piece, so I don't think the shiny metal is part of your air control. It almost looks like a piece of extra flashing left in there from packaging or assembly or something.

THIS
 
Soooo? Are you saying you have a straight up and out vent system? 4 feet of connector pipe seems short? Or is the stove on a tall hearth? It sounds like it but figured I'd confirm.
Here is a photo---the pipe goes straight up al the way.
 

Attachments

  • [Hearth.com] Green Mountain 40 Not Working
    IMG_2744.webp
    43.1 KB · Views: 707
I do not think it should be there. I do not have that shiny piece on my stove. We can see what @Nigel459 says. Also, when you close the air intake, I can see the intake damper behind the shiny piece, so I don't think the shiny metal is part of your air control. It almost looks like a piece of extra flashing left in there from packaging or assembly or something.
I pulled off most of the panel underneath (hateful job on a Brand New stove) and here are the photos. What you see is the shiny piece that was in the other photos, only now it is uncovered. Does not look like it belong there because it closes off the airflow.
 

Attachments

  • [Hearth.com] Green Mountain 40 Not Working
    IMG_2743.webp
    31.4 KB · Views: 450
Here is a photo---the pipe goes straight up al the way.
No ceiling support for your chimney pipe?
Anyway. Straight up and out it is. Let us know what you find out on the intake air control.
 
No ceiling support for your chimney pipe?
Anyway. Straight up and out it is. Let us know what you find out on the intake air control.
Good catch! The pipe is actually supported in the attic because that is what the fireplace company sold me. It also has a support where it goes through the roof----so both supports are "hidden" in the attic.
 
I believe that the part replaced by the manufacturer was #38, Pipe:LPAO
I cannot tell from the diagrams if the air intake is blocked---when I look at the 4" intake hole on the bottom of the stove I can see that there is a metal shield that is bright metal, not black like all the rest, that covers over 3/4 of the hole. It does not look like it is cutting off the air, but it sure as hell is restricting the in-going air.
I am attaching two photos, first one shows the intake with the shutter open and the other with the shutter closed. Maybe that bright piece of metal should not be there!!!
That metal plate is not there on my GM40 stove.

You have me very curious about this! Even with the plate installed on yours I see a small crack of airway. Restricting the air in a similar fashion I have been able to achieve the advertised burn times... BUT only after things are up to temp and cruising. Especially with oak or the black locust I use, one could never get things going without more air!

I wonder if hearthstone is trying to save face putting in these restrictive plates after such crazy advertised burn times?!?
 
That metal plate is not there on my GM40 stove.

You have me very curious about this! Even with the plate installed on yours I see a small crack of airway. Restricting the air in a similar fashion I have been able to achieve the advertised burn times... BUT only after things are up to temp and cruising. Especially with oak or the black locust I use, one could never get things going without more air!

I wonder if hearthstone is trying to save face putting in these restrictive plates after such crazy advertised burn times?!?

Not sure what you mean by "such crazy advertised burn times" but why they would put a piece of bare metal on the stove is beyond me. NO other part of the stove is bare metal. EVERYTHING is black, treated metal. This piece, which is not more than 14 months old is already rusting!!!n Not right!!
Attaching a couple of photos of the plate, removed, that show it to be a cheap, stamped, untreated, rusting piece of metal. And also a photo of the air intake with the shutter completely closed. You can see that there is still a very tiny gap so that the shutter does not close off the air supply 100%.
I have not heard about these stoves can over-fire easily, or burn at too high a rate because I have never gotten the stove to burn a load of wood properly. However, with your comment I might very well install a damper in the flue.
 

Attachments

  • [Hearth.com] Green Mountain 40 Not Working
    IMG_2746.webp
    70.5 KB · Views: 390
  • [Hearth.com] Green Mountain 40 Not Working
    IMG_2747.webp
    57.6 KB · Views: 318
  • [Hearth.com] Green Mountain 40 Not Working
    IMG_2748.webp
    34.4 KB · Views: 332
If it was me I'd pull that piece and see if it makes a difference. Something is definitely weird here. Between that piece, the recalled LPAO, and the overall difference in the air intake between yours and mine, I think hearthstone definitely changed something along the way. I will post some pics from under mine later, it's hard to explain, but the 4" hole in the sheet metal under there, does not line up with my air intake/control. If you look under the stove, you can barely see the gap. I have to stick my pinky finger in there to feel the air control open/close. Whereas on yours it looks like it fills half the hole in the shroud.
 
It always struck my as strange that the hole in the sheet metal shroud does not line up with my air intake slot. You can barely see the slot on mine, yours is atleast aligned with half the hole.
Unless it's a 40 vs 60 difference. @cabinwarmer would have to confirm.
 

Attachments

  • [Hearth.com] Green Mountain 40 Not Working
    IMG_20201210_210753892.webp
    59.9 KB · Views: 335
It always struck my as strange that the hole in the sheet metal shroud does not line up with my air intake slot. You can barely see the slot on mine, yours is atleast aligned with half the hole.
Unless it's a 40 vs 60 difference. @cabinwarmer would have to confirm.
I hate to be a griper but this all appears to me to be shoddy workmanship.
With the recall and the "extra" piece of sheet metal, I cannot feel confident with the huge amount of money I spent. I have also spent hours and hours working on this stove which is complete crap. Can you imagine buying a washing machine and then spending hours working on it before you ever get to use it? No one would put up with that.
I did not mention it but earlier today while investigating I opened the cover for the catalysts and found them to be installed cock-eyed with the fiberglass seal coming out all around. And no, I never turned the stove more than 30 degrees in any direction; just enough to get it on the dolly. Another example of shoddy work.
I have contacted the company but they have failed to respond and they do not publish a phone number now. My next move will probably have to be to send them a formal legal letter requesting repayment for my time and effort along with an explanation for all the crappy work. Often that is the only thing that these companies understand----money.
I am going to fire up the stove tonight and see if it finally works.
BTW, how well does your stove work? And how do you start your fire? And last, do you ever have the door open, either when starting a fire or adding wood, and it does not pour smoke into your house?
Many Thanks
 
I hate to be a griper but this all appears to me to be shoddy workmanship.
With the recall and the "extra" piece of sheet metal, I cannot feel confident with the huge amount of money I spent. I have also spent hours and hours working on this stove which is complete crap. Can you imagine buying a washing machine and then spending hours working on it before you ever get to use it? No one would put up with that.
I did not mention it but earlier today while investigating I opened the cover for the catalysts and found them to be installed cock-eyed with the fiberglass seal coming out all around. And no, I never turned the stove more than 30 degrees in any direction; just enough to get it on the dolly. Another example of shoddy work.
I have contacted the company but they have failed to respond and they do not publish a phone number now. My next move will probably have to be to send them a formal legal letter requesting repayment for my time and effort along with an explanation for all the crappy work. Often that is the only thing that these companies understand----money.
I am going to fire up the stove tonight and see if it finally works.
BTW, how well does your stove work? And how do you start your fire? And last, do you ever have the door open, either when starting a fire or adding wood, and it does not pour smoke into your house?
Many Thanks
I completely understand your frustration. I would be pissed too. 2 to 3 k is a huge amount of money to spend on something and have it not work right. I'm not defending the company, just trying to help you get it fixed.
I actually haven't used mine yet, I bought it a month ago because I found a good price and was worried if I didn't scoop it up covid might make it hard to find a stove down the road. I have to use up my oil tank and tile my hearth, etc, gonna be another month or two before I can report back on the performance.
There have been 1 gm40, 1 gm60, and 1 gm80 owners on here who have given really positive reviews. And then there have been 3 or 4 people who have reported negative issues with their green mountains - with the main complaint being smoke roll out and poor draft.
I'll be curious to see if the catalyst and air intake corrections help any with your setup. I hope so. Good luck!
 
For the record I’m very happpy with my GM40. I have cleaned the flue and agree the cat sits lightly in a “rope style gasket” which was easy to clean and replace. Much like a Woodstock stove according to how they are reported to work.

Your experience sounds crappy. Sorry to hear it.

to answer your question, the stove starts and works similarly to my other stoves, about six in different installations. No I have had no problem with smoke. Caerainly no smoke pour out in the room.
I hate to be a griper but this all appears to me to be shoddy workmanship.
With the recall and the "extra" piece of sheet metal, I cannot feel confident with the huge amount of money I spent. I have also spent hours and hours working on this stove which is complete crap. Can you imagine buying a washing machine and then spending hours working on it before you ever get to use it? No one would put up with that.
I did not mention it but earlier today while investigating I opened the cover for the catalysts and found them to be installed cock-eyed with the fiberglass seal coming out all around. And no, I never turned the stove more than 30 degrees in any direction; just enough to get it on the dolly. Another example of shoddy work.
I have contacted the company but they have failed to respond and they do not publish a phone number now. My next move will probably have to be to send them a formal legal letter requesting repayment for my time and effort along with an explanation for all the crappy work. Often that is the only thing that these companies understand----money.
I am going to fire up the stove tonight and see if it finally works.
BTW, how well does your stove work? And how do you start your fire? And last, do you ever have the door open, either when starting a fire or adding wood, and it does not pour smoke into your house?
Many Thanks
 
I completely understand your frustration. I would be pissed too. 2 to 3 k is a huge amount of money to spend on something and have it not work right. I'm not defending the company, just trying to help you get it fixed.
I actually haven't used mine yet, I bought it a month ago because I found a good price and was worried if I didn't scoop it up covid might make it hard to find a stove down the road. I have to use up my oil tank and tile my hearth, etc, gonna be another month or two before I can report back on the performance.
There have been 1 gm40, 1 gm60, and 1 gm80 owners on here who have given really positive reviews. And then there have been 3 or 4 people who have reported negative issues with their green mountains - with the main complaint being smoke roll out and poor draft.
I'll be curious to see if the catalyst and air intake corrections help any with your setup. I hope so. Good luck!

Removal of the rusted blocking plate has helped give the stove much better draft. However, you still cannot get this stove running without having the door open a crack. Close it while getting the fire started and the fire snuffs out. You need to get the stove up to around 300 before it will allow you to close the door. And once the stove reaches catalyst temperature, closing the bypass actually give better draft. But it takes a long time to get there.
The fire has been burning for over 2 hours now and the stove is getting close to 300F. This is a slow starting stove. During that time there is still the problem of smoke coming out the front when you open the door to add wood or whatever. Once the temp gets above 300 the smoke problem diminishes and you can add wood most of the time without a problem. From 3-400 or so the stove performs OK, but not great. It does not put out a lot of heart; maybe the 40 is just too small for anything but one large room.
There is another problem with this stove which is fundamental to the design which is that the entire combustion vents through the front of the stove right above the door. Which means that if you have a fire with good size flames and you open the door the flames come out the front of the stove. I do not and never will understand the insane design.
At this point, with all the problems I have had and with the mediocre performance and clear danger with the flames, I expect to have to ship the stove back to the dealer and buy another brand.
There must be the "Toyota" of stoves that works perfectly, needs no help and is cheap and safe to operate so I will have to start looking for that reliable brand and model.
Good Luck and Thanks so much for pushing me along to get the issues resolved.
 
For the record I’m very happpy with my GM40. I have cleaned the flue and agree the cat sits lightly in a “rope style gasket” which was easy to clean and replace. Much like a Woodstock stove according to how they are reported to work.

Your experience sounds crappy. Sorry to hear it.

to answer your question, the stove starts and works similarly to my other stoves, about six in different installations. No I have had no problem with smoke. Caerainly no smoke pour out in the room.
Thank you for the feedback. I don't believe my stove works properly but I am glad yours does!
Since you own so many stoves, can you share with me what you think is the best all-around/top performer? I need to replace the GM40 and would appreciate any advice.
 
Here is my main opening (GM60) from below the stove. One picture is completely open, the other completely closed. The plate is inside and not visible. I have @ 22' of straight up 6" DVL inside and stainless out side. I have plenty of draft. Light the stove with a top down method. Good example of your stove on the Hearthstone youtube web page for this method. It takes about 5 minutes to get my GM60 up to your 300F (flue temp)you mentioned. I let it go for around 45min and the flue temp over 550F then check the cat gauge and activate the cat. The flue temp drops around 75-100F and I run it there for about 15 min. I then load in the splits on hot coals with a small flame. It take 15 minutes to catch and then I adjust to keep my flue temp around 450F. I get hours of burn at this temp and the cat stays in the middle of the gauge. I have talked with Hearthstone several times (Jim) and he has always been helpful. The number on the web page is 877-877-2113. Was the recall just for GM40? I have not seen anything for the GM60.

added:
* that piece you show is not on my gm60
** one of my CAT's was not installed all the way either, it is from shipping and in my case, the installers. They did not handle with so much care.
I do get some smoke if the flue temp is not hot, you shouldn't have to open the door when cold if you utilize the top down start. Only open when adding wood. To open - Disengage CAT, open intake, crack door, wait 5 seconds and open slowly.


Dave

[Hearth.com] Green Mountain 40 Not Working [Hearth.com] Green Mountain 40 Not Working
 
Last edited:
  • Like
Reactions: tabner
OK, I'm having the same issue with that piece of sheet metal blocking the air intake, but on a Green Mountain 40. For those who had this similar problem:

(1) Does removing it seem to be a good idea? Mine covers practically the entire intake area except for about a 1/4-3/8" gap. The control lever plate opens or restricts this gap by a very small amount. Having trouble starting fires without door open.

(2) How did you get it out? I've tried working it back and forth with pliers, but it has only gotten a bit loose.

[Hearth.com] Green Mountain 40 Not Working