Jotul Alpha goes out when door is shut

[arstearns]

Hello all,

I have a Jotul Alpha wood burning stove. It is some 13 years old and it came with the house that we have lived in for 2+ years now.

It has worked fine up until the end of the last heating season. It was most impressive when the fire is up to heat and I closed the door - the flames went into slow motion and the heat really increased.

Toward the end of the last heating season, when I shut the door the fire would just go out within a minute or two.

I have combed through the forums here and it seems unlikely that the problem would be construction (length of pipes, etc) since the existing configuration worked fine for almost 2 full years (with the assumption it worked fine for the preceeding 11 years before we lived here).

Can a spent combustor be the problem? (it has likely never been replaced)

The sheet metal chimney and the sheet metal ventilation tube under the stove are clean and unobstructed.

I would appreciate any thoughts you might have as to the cause of this problem and its resolution.

Warmly, Al Stearns
Pisgah Forest, NC

 

[begreen]

It could be a clogged combustor. Have you examined it?

 

[arstearns]

Yes, I have inspected it. It is not clogged. I can see through the honeycombs just fine. There are some cracks and a few small missing pieces (not canned, just ceramic). It is 4" by 7".

I suspect the combustor is 13 years old, having never been replaced.

It sits in its space near the top of the wood stove with two cloth cords (gaskets) on its bottom and two cloth cords on its top (honeycombs on the sides).

Warmly, Al Stearns
Pisgah Forest, NC

 

[begreen]

Well, the good news is that you can still get a combustor for it. Given the way the stove was designed, it seems like the combustor has to function well when the door is closed.

Before you buy a new one you might want to try soaking the cat in a 50/50 solution of white vinegar and warm water. It's worth a try to see if it can be cleaned up.

Read the posting by Mike at the bottom of this thread:
https://www.hearth.com/talk/threads/4350/

 

[arstearns]

So you are familiar enough with the Jotul Alpha's design that you suspect a spent combustor is the cause of the fire going out when the door is closed?

When the door is cracked open the fire is fine but does not burn super hot like it used to when the door is was closed.

As I understand a combustor (from posts in this forum) it helps burn the fuel in the smoke for greater heat and to get the most out of the wood. It would make sense that a spend combustor would not do that. I does not seem to make sense that a spent combustor would inhibit air flow through the bypass area (used when the door is closed). As a test, would it make sense to remove the combustor and see if the fire still goes out with the door closed? (I understand the greater heat and getting the most out of the wood would not happen with the combustor removed)

I will indeed trust your judgement since I am a computer and networking tech and not a wood burning stove expert.

Warmly, Al Stearns
Pisgah Forest, NC

 

[begreen]

No, no, not at all. Sorry if I gave you the wrong impression. I have never run the Alpha. It's a pretty rare breed. I read up what I could find on it's design, which seems to be somewhat unique. The stove seems to be setup with a minimal air supply for feeding the combustor with the door closed.

Most cat stoves use a bypass damper to allow the fire to build up to a temperature adequate to get the combustor burning the wood gas. The Alpha appears to not have a bypass. Instead the door must be left ajar until the fire is up to temp. Is that correct?

You've indicated that you've cleaned out and confirmed that the stove flue is clear and clean. So I am guessing that either the air supply is getting blocked or the combustor no longer is firing off to burn the wood gas. That's why I suggested the vinegar soak first. You might PM Craig (webmaster) and ask if he burned this unit for another perspective.

 

[abasilica]

Hello,

I used an alpha for many years. The stove heated my 1600 sq. ft. cape with 8 hour+ burn times.

The problem you describe only occurred when the combustor was clogged. You could remove the combustor via the top plate and run the stove without it to verify the combustor is or isn't the problem (just be sure to reinstall the top plate first).

Good luck,

AB

 

[arstearns]

Thanks for your fine input, AB.

The old combustor was not clogged. However, it was likely 10 years old or more. I have since gotten a new one.

Also, in my research I found that the stove must be hot before closing the door. This I may not have done properly (my first wood stove, came with the house I have been in for 2+ years). According to the manual that accompanied the new combustor, the fire needs to burn for a good 20 to 30 minutes before closing the door and bringing the combustor into play.

Any suggestions on a good thermometer to place on the stove to monitor the temperature? According to the manual that accompanied the new combustor, the internal temperature needs to reach 500 degrees for the combustor to be ready to do its job.

Warmly, Al Stearns
Pisgah Forest, NC
USA

 

[johnnywarm]

Any suggestions on a good thermometer to place on the stove to monitor the temperature? According to the manual that accompanied the new combustor, the internal temperature needs to reach 500 degrees for the combustor to be ready to do its job.

Warmly, Al Stearns
Pisgah Forest, NC
USA[/quote]


Jotul makes a good thermometer.thats what i use.

 

[arstearns]

Thanks for your input.

I went to www.jotul.com and could find no reference to any thermometers.

Would you happen to have a link or a part number or model name of the thermometer you refer to?

Warmly, Al Stearns
Pisgah Forest, NC
USA

 

[johnnywarm]

Thanks for your input.

I went to www.jotul.com and could find no reference to any thermometers.

Would you happen to have a link or a part number or model name of the thermometer you refer to?

Warmly, Al Stearns
Pisgah Forest, NC
USA

Al i got it at my new jotul deal the last time i was there.it was like 15 bucks.

 

[EddyKilowatt]

I guess this is winding down, but would like to comment that the combustor -- when operating properly -- puts a big shot of heat into the flue gas. Heat times flue height equals draft (with some fudging for the units).

Even if the combustor's not restricting flow, if it's not combusting, it could be the cause of a low-draft lazy fire situation.

Will be interested to hear the results with the spankin'-new combustor.

Eddy

 

[arstearns]

Hello Eddy,

Thanks for your input.

We will probably have our first fire of the season in a week or two.

I will be glad to let you know.

Warmly, Al Stearns
Pisgah Forest, NC
USA

 

[johnnywarm]

Hello Eddy,

Thanks for your input.

We will probably have our first fire of the season in a week or two.

I will be glad to let you know.

Warmly, Al Stearns
Pisgah Forest, NC
USA

Good Luck Al. Please let us know how it turns out.

John

 

[abasilica]

Ah, a drafting problem.

In my particular installation I used the top exit from the stove and had about 16' of pipe at room temp in a lofted living room. I can't say I ever had a
draft problem.

One other point though. Over the years I learned the stove likes well seasoned wood. In addition to lighting easily you can cut the stove back and get a nice long burn
with complete combustion. Low and slow. A few times I had wood that wasn't quite seasoned enough and I did have to struggle to get it lit and keep it burning. In that case I might have to
reopen the door to get the wood burning hot and I would have to leave the draft open wider than with seasoned wood.

As for the thermometer, the Jotul manual indicates there is one but I was never able to get my hands on one. I wound end using a generic type
and placed it on top of the stove near the the center with the probe hanging down in the grate. Not perfect but when it read 350 or so I could tell
the combustor was working. I used it more to make sure I wasn't overfiring.

Good luck with your stove,

AB

 

[arstearns]

Hello all,

I have had a few fires this season and they were all successful.

The key is getting the fire hot BEFORE closing the door (which uses the combustor air path). I got a Rutland magnetic thermometer and placed it on the INNER top of the stove. The outer top is about 2 inches away from the inner top resulting in inaccurate temperatures. I can see the thermometer through the grating on the outer top of the stove.

The fire gets up to about 200 F in a half hour or so. At that point I close the door and the fire gets up to 450 - 500 F for a nice long burn.

Thanks for your fine help!

Warmly, Al Stearns
Pisgah Forest, NC
USA

 

[begreen]

Glad to hear that she's working well for you now. It's an interesting stove. Can you post a picture for us?

 

[arstearns]

Sure - here you go!

Warmly, Al Stearns
Pisgah Forest, NC
USA

 

[begreen]

Nice! That's an amazing stove. Very nice design. I've seen some sketches of it, but it looks much better in your picture. Thanks for posting!

 

[arstearns]

Glad to do it!

Warmly, Al Stearns
Pisgah Forest, NC
USA