Considering a new GM60, advice needed!

[barnkat]

Hello folks!

I am new to the wood stove world (my partner has had one before, long ago) and I need some help figuring out if we’re making a good decision here.

Just bought the house and moved in this summer—and are gradually discovering all the exciting DIY mistakes the previous owners left us with 🤪 the situation is a little unusual, so bear with me.

The house was a small brick ranch, and then they stuck on a 1200 sq addition—one big great room (and associated basement). Peak height is 12’4”. The old house is heated with a standard gas furnace, but the great room has no HVAC at all—it is only heated by a freestanding wood stove. The two parts of the house are very distinct temperature zones; you feel it clearly when you step through the door between them, and the addition is damn cold in the morning when the stove is out and the furnace is heating up the old house just fine. The kitchen is in the addition and there’s a bathroom as well, so it’s important that the heat last a long time to prevent any frozen pipes in extreme weather. We’re in Wisconsin, so it does get pretty cold.

The stove they left us is… less than desirable. We’re ready to replace it (yes… would have been great to attend to this six months ago) with a new, clean, efficient stove. We’ve almost settled on a Hearthstone GM60, but I keep reading about all the troubles people are having with smoke rollout/draft and am wondering if we’re making a mistake. I’m starting to understand the basics—make sure to use dry wood, have a tall enough chimney, and build/load properly—but I’m nervous we’re gonna get this thing and have a big smoky mess on our hands. Any reassurances or warnings to offer? And does the 60 seem like the right size for our space?

Our sweep/installer advised that the old pipe all needs to go (except the box that goes through the crawl space), which makes sense as it’s all beat up and connected strangely—like I said, bad DIY stuff going on here. So we’ll be getting pretty much an entirely new chimney, and can size it as needed; seems like at least 14’ from what I’ve read. There’s no problem with the 3-10 rule. We have woods around the house but not super close, there’s probably at least 15-20’ between the chimney and nearest tree. Advice on how tall to go?

Also—double or single wall pipe? Inclined towards single to enjoy the heat from the pipe, but I don’t know what I don’t know.

There’s only 14” of clearance from the stove pipe to the one wall, but installer said it’s ok because the wall is tiled. 19” clearance on the other side. Does that seem ok?

Reasons we’re interested in the GM60:
Can get it now
Both efficient and clean burning
Aesthetic
Comfortable with a cat stove
Long heat length—important

I was super interested in the progress hybrid from Woodstock but they’re months out on production. Also considered the BK Princess but it looks like it has a shorter log length and shorter burn time, and I haven’t found one locally yet.

Here are pictures—happy to add any details! Thanks for any thoughts and opinions, the dealer we’d be buying it from wasn’t super helpful with our questions. Installer (sweep) was much better but not as familiar with this particular stove.


Why they put that little bend at the top… we’ll never know! When the new pipe runs straight down the clearance to the wall will be 14”. Currently it’s 16”.



Big room… tall ceiling

 

[bikedennis]

BK Princess is quite large. 2.9 firebox. Takes 18" wood. Also, BK's have probably the longest burn times due to the thermostat.

 

[begreen]

Also considered the BK Princess but it looks like it has a shorter log length and shorter burn time, and I haven’t found one locally yet.

The BK Princess is a true cat, not a hybrid and a better design, imo. I'm pretty sure it will have a notably longer duration burn than the GM60. Log length is often pushed as a marketing point, but in practice, this usually means a shallow firebox that needs to be E/W loaded and thus less capacity. A more square firebox is more flexible for loading either E/W or N/S.

That said, either one will be an improvement over the current stove. The installation does not look like it has either the proper clearances for the stove or the stovepipe

Draft may also be an issue for the GM60. What is the total flue system height from stovetop to chimney cap?

 

[barnkat]

The BK Princess is a true cat, not a hybrid and a better design, imo. I'm pretty sure it will have a notably longer duration burn than the GM60. Log length is often pushed as a marketing point, but in practice, this usually means a shallow firebox that needs to be E/W loaded and thus less capacity. A more square firebox is more flexible for loading either E/W or N/S.

That said, either one will be an improvement over the current stove. The installation does not look like it has either the proper clearances for the stove or the stovepipe

Draft may also be an issue for the GM60. What is the total flue system height from stovetop to chimney cap?

This is super helpful, thanks! If you don’t mind answering, what makes the BK Princess a better design in your mind? Just that you prefer a true cat to a hybrid or something specific about the GM?

Total flue height is yet to be determined—the whole chimney system is whack and needs replacing, so we’ll do whatever is needed. Would love your advice. Same with the clearances, they seem too small to me—14” for the pipe if done straight up, but installer said it was OK because of the tiled wall. Thoughts?

 

[begreen]

The catalyst placement and bypass arrangement are much better in the Princess. And the stove has thermostatic operation for operation over a wider temperature range. It will also work on a shorter flue system that the GM60 which prefers a strong draft. Another stove to consider would be the Woodstock Ideal Steel, which is a hybrid, but of good design and performance. Another good cat design is the Regency 3500. In non-cats, there are several more choices.

The single wall pipe needs to have 18" clearance to combustibles, the nearest combustible being the mantel and then the studs in the wall behind the tile. As far as I can see the tile wall provides no code legal clearance reduction at all. The boxstove needs 36" clearance and again, the tile wall does not offer a reduction.

 

[BKVP]

OP. In order for wood stove manufacturers to comply with lowered standards mandated by EPA, many, many manufacturers began redesigning their wood stoves.

There are two methods that can be employed to reach these standards. You can employ chemical reaction (catalyst) or thermal (secondary combustion).

We've made catalytic wood stoves since 1982, even before regulation of wood heaters. I make this statement so that you appreciate we are experts in the technology.

When buying any catalytic equipped wood stove, recognize that you will be required to optimize the chimney for peak performance. Any catalytic wood stove.

If the added expense and effort of optimization is not something you wish to tackle/address, you may want to look at secondary combustion models. Pacific Energy is one such company. Exhaust temperatures are higher and draft is less complicated.

If you are willing to tackle the upgrade of venting and the attached expense, go get the stove you like and want!

 

[Todd]

Go with double wall pipe the heat off single wall will be minimal. Double wall will also help the draft and only requires 6” clearance.

 

[Tar12]

I agree totally with Todd...Double wall pipe makes your clearance issue a non issue...do not get hung up on burns times because as the temperatures drop so do your burns times to keep up with heat demand...I am on my 6th winter with a BK Princess and I can tell you that this stove will meet and beat the GM60 advertised numbers and thats with wood cut to 16 inches...I loaded yesterday afternoon at 5:30 pm and walked in the door at 7:45 pm today and the stove room was 73 degrees and I had plenty of coals left to fire right back up...I do this day after day until the temps dive then its 12 hour cycles and if we encounter single digit weather then its 8 hour burns...do yourself a favor and pass on the GM60 and disappointment and find yourself Princess...you can thank us later...

 

[KDubU]

Based on your initial selection of the two stoves, the Hearthstone and the Woodstock, I am going to say you want some form as well as function? If that is the case then the BK Princess is not your stove. This is my opinion but the BK Ashford 30 is a nice looking and performing stove. There are also others you may consider such as certain Jotul models and some Lopi I have read good reviews on.

We are buying a Progress Hybrid as it ticked all the boxes and have had previously: Hearthstone, Jotul, and Vermont Castings (older versions). We liked the Hearthstone and Jotul a lot.