GM60 Flue Height

[51221]

Hello,

I have been lurking since we moved in to our house 6 years ago. The house had an old Fisher grandpa.

Decided to replace it because the stove and chimney were in bad shape. The local dealer sold me a hearthstone GM 60.

I'm having smoke roll out problems mainly when starting a fire before it takes off. I think this is pretty common with this stove. Once it gets going it works well. I notice it more on wet mild days like today.

I wanted opinions on the minimum flue height. The manual recommends 14' minimum off of the floor. The stove sits up on an elevated hearth, I have low ceilings, and a low roof pitch resulting in about 12' from connector to cap, which gives me 17' from the floor of the house to the cap.

Would I benefit from adding two more feet of chimney? The pipe is not cheap and the chimney is already about 6' above the roof where it goes out so my concern is being able to clean the chimney if it's over my head.

Thanks in advance! I've already learned a lot here!

 

[begreen]

This stove has a high draft requirement. Is the flue system straight up from the stove through the roof? You could put on an additional 3' section of cheap warm air duct at a test to see if there's a notable improvement.
Is the stovepipe already braced at the 5' level?
Another thing to try is to open a nearby window an inch and see if that makes a notable improvement.

 

[51221]

Is the flue system straight up from the stove through the roof? You could put on an additional 3' section of cheap warm air duct at a test to see if there's a notable improvement.
Is the stovepipe already braced at the 5' level?
Another thing to try is to open a nearby window an inch and see if that makes a notable improvement.

Flue is straight up. It is already braced at 5'. The house is not particularly tight. I've cracked the windows and even left the screen door open.

More or less wondering if I misinterpreted the manual and the stove really wants 14' of chimney. If the consensus is it should help it's worth the $250 in pipe. I know this stove wants a lot of draft.


Thanks for the quick reply!

 

[begreen]

The draft spec for the stove is pretty high in comparison to other stoves. I would do the quick test on a calm day with 3-4' of the warm air pipe if uncertain. It will cost under $10. All else sounds good.

What brand of chimney pipe is this?

 

[51221]

The draft spec for the stove is pretty high in comparison to other stoves. I would do the quick test on a calm day with 3-4' of the warm air pipe if uncertain. It will cost under $10. All else sounds good.

What brand of chimney pipe is this?

Duravent Galvalume.

Now if I were to add 2' what are your thoughts on adding a 2' piece versus swapping my 4' piece for a 6' piece? Does each piece need a brace?

 

[begreen]

DuraTech or DuraPlus chimney? DuraTech galvalume 36" is about $150. DuraPlus is less.

Home :: Chimney Pipe / Venting Pipe :: Wood/All-Fuel Piping :: 6 inch :: DuraVent DuraTech 6 :: DuraVent 6'' x 36'' DuraTech Chimney Pipe - Galvalume - 9406GA // 6DT-36

M&G DuraVent 6" x 36" DuraTech Chimney Pipe - Galvalume - 9406GA* Non CF (Carton Filler) pipe of this length needs to be purchased with at least two other pieces of similar brand pipe. Please call or e-mail us if you have any questions.Designed for applia

woodstovepro.com

 

[51221]

I have Duratech pipe. Is there any problem with having a 4' section supported at 5' then another 3' section unsupported?

 

[tabner]

When you say “smoke roll out problems” can you describe more specifically what you mean?
Because I will say, I have 30+ feet of chimney (not straight up) and I still have smoke roll out if I’m not really careful and time my reloads perfect. Not being rude (it took me a while to figure it out, and reading the manual three times) but you have to be very careful about how you open the door - open the bypass, crack the door and wait five seconds, then open the door really slowly.
I kept having the urge to yank the door open because I was scared of the smoke, but I think that quick opening creates a bit of a suction and pulls a big puff of smoke out the door.

 

[begreen]

I have Duratech pipe. Is there any problem with having a 4' section supported at 5' then another 3' section unsupported?

No, that's ok. We have 7' sticking out of the roof. A second brace is required at the 10' level.

 

[51221]

I usually leave the door open until the fire gets going really good then I close the door and don't open it until it's almost coals. I typically wait until I see the cat probe start to drop to reload. Then I shut off the fan, open the primary air and bypass while I get wood and I open the door with a pause and let the smoke clear. Usually no smoke in that situation.

When I get a lot of smoke in the room is if I jump the gun and close the door all the way and the fire dies. I have to open it up to adjust logs. The smoke just sits and curls in the box. That's what made me think I might need more draft.



Thanks begreen and Tabner.

 

[tabner]

I usually leave the door open until the fire gets going really good then I close the door and don't open it until it's almost coals. I typically wait until I see the cat probe start to drop to reload. Then I shut off the fan, open the primary air and bypass while I get wood and I open the door with a pause and let the smoke clear. Usually no smoke in that situation.

When I get a lot of smoke in the room is if I jump the gun and close the door all the way and the fire dies. I have to open it up to adjust logs. The smoke just sits and curls in the box. That's what made me think I might need more draft.



Thanks begreen and Tabner.

I have the exact same situation. I find it very frustrating. On cold starts I have to be very specific on how I build the fire before lighting, to avoid this scenario. On reloads I find that if it snuffs out I just need to be more patient, the coals will eventually light the new load, or I can keep the door cracked for a while until it lights again. I have found I can leave the door cracked indefinitely with no smoke spill, it’s only once I open it past 3” or so that smoke starts pouring out.

 

[51221]

I have the exact same situation. I find it very frustrating. On cold starts I have to be very specific on how I build the fire before lighting, to avoid this scenario. On reloads I find that if it snuffs out I just need to be more patient, the coals will eventually light the new load, or I can keep the door cracked for a while until it lights again. I have found I can leave the door cracked indefinitely with no smoke spill, it’s only once I open it past 3” or so that smoke starts pouring out.

Yup, exactly. There's a certain point where you open the door wider and the smoke stops bending up and around the baffle. It's just a very tight turn for the smoke.

This morning I had a good bed of coals and by the time my coffee was done the reload had caught with no fussing around.

 

[51221]

Went ahead and added 3' to my flue so I'm at 15' straight up.

Just starting my first burn now and I see an improvement. On the cold start I was able to open the door with almost no roll out. It seemed to heat up quicker and now that I have the door closed I see a much more aggressive secondary burn happening.

This is under pretty poor draft conditions, it's warm and foggy out. I'll update again as a resource for other GM60 owners.