Broken part on a Jotul Castine, plus: doghouse differences?

[Sparky31]

I'm new to stoving but getting along pretty well thanks to experienced friends and Hearth.com. Our new Jotul Castine has about 12 burns through it now. I've kept a close eye on the temperatures and have gotten skilled with a quick heatup to about 550 degF (top dead center of stove), then tapering off right at 600 degF.

Last night we burned for about 5 hours between 500 & 600 degF. By bedtime, the stove had a great glowing coal bed that I had allowed it to burn down to, with a temp below 400 degF. Left the air fully on and went to bed.

This morning I checked the stove and there was just a hint of heat left. For some reason, can't recall, I touched the air control rod to move it from 100% open to 0% open. And that's when the outermost part of the rod simply fell onto the ash lip. Holy smokes!

Examination shows the weld between the outermost part of the rod and the central pivot point "ring" failed. All I can figure is that either the rod's metal was bad or the weld was inferior. I certainly haven't overfired the stove.

Called my local dealer and got a warranty claim going. However if they say it will take 6 weeks, I will just order the part myself for $45 or so. Gotta have the fire for Christmas.

In the process of examining this failure, I've learned how the air control rod manipulates the air port in the doghouse, which I removed then reinstalled. Boy, the EUR doghouse sure is different than the USA version, anyone know more about that? Also, there is a long, third bolt in the doghouse that doesn't mate with a corresponding hole, and seems to act as a travel stop for the air port slider. Any ideas on that function?

I'll try to post some pics here.

The spooky part was imagining ramping up the stove to 500+ degrees, then having the air rod fail. Not good.

With the ash lip removed, I can see how I could still move the air control with a short piece of bent wire, in case the inside part of the rod's weld fails as well. I hate to stop burning because of this part, but since I have the bottom heatshield, I couldn't easily access the air intake if the stove tried to run away.

 

[weatherguy]

That's one thing that irks me of some in the stove industry. We use stoves to heat our house for the whole winter season but they take so long to get a replacement part in the middle of burning season. One of the reasons I went with Woodstock, if i need a part its here in a few days.

 

[Sparky31]

So Jotul NA still hasn't sent me the replacement part. Luckily I went ahead and got one last week from an online vendor. In the meantime, I crafted a piece of heavy, stiff wire shaped such that I could use it to reach in and move the air control plate, through the spot where the broken air control rod would be. This slot is easily accessed when the ash lip is removed. The bolt that holds the rod in is 13mm and with it out of the way, its pretty easy to access the air control plate. I probably did 3 burns before the new rod arrived in the mail.

The new air control rod was easy to install. I put a cheap 13mm wrench in my tool drawer kept near the stove, in case the rod breaks again during a burn. I won't have to go running looking for the wrench.

 

[sroof]

In the process of examining this failure, I've learned how the air control rod manipulates the air port in the doghouse, which I removed then reinstalled. Boy, the EUR doghouse sure is different than the USA version, anyone know more about that? Also, there is a long, third bolt in the doghouse that doesn't mate with a corresponding hole, and seems to act as a travel stop for the air port slider. Any ideas on that function?

I too have the Castine and was curious about the USA and EUR doghouse (referred to as "Inspection Cover" in the Jotul F400 manual parts list). I found what seems to be a knowledgeable description here: https://www.whatstove.co.uk/jotul-f-400-stove-review-5476. But I'm a little confused by the author's description of the "clean burn system" and the "air wash system" - I don't see evidence of two separate systems. It looks to me like all the combustion air flows past the sliding vent inside the doghouse, up the left and right side burn plates, then through the secondary air chamber across the top inside the stove (i.e., the part with all the air holes). Can anyone better explain the airflow through the Castine?

And that 3rd long bolt in the doghouse (aka inspection cover) - I've assumed that it's a travel stop and/or simply keeps the sliding vent plate from jumping out of place.

 

[sroof]

Well, I found an answer to my questions about airflow in the Castine in the 2016 manual available from (broken link removed to https://jotul.com/us/products/wood-stoves/jotul-f-400-castine#technical-area). In case anyone is curious, here's the description and picture from this manual:

5.4 Air Flow and Control
Your Jøtul F 400 is designed to support efficient combustion and heat transfer by directing air through the stove in two separate channels; Primary and Secondary. See figure 11.

Primary air is manually regulated by a lever and valve at the front of the stove. The valve position controls the volume of primary air entering the firebox and thereby affects fire intensity, heat output and burn time. Primary air is directed to the main body of the fire through air ports at the front of the stove. Separate manifolds at each side also deliver pre-heated primary air at top of front plate to create an ’air-wash” to help keep the viewing glass clean.

Secondary air allows combustion of volatile gas and other byproducts of primary combustion that would otherwise enter the atmosphere unburned. This unregulated air is preheated as it passes over the back of the stove and through a stainless steel manifold at the top of the firebox. This additional hot oxygen allows any unburned gasses to be burned inside the stove. The action of secondary combustion can be readily seen through the viewing glass a slow, rolling flames suspended over the main fuel bed and smaller jets of flame extending from the secondary manifold ports. At the same time, no smoke will be observed exiting the chimney. This is evidence that the stove is operating at the so-called “sweet-spot” wherein optimum efficiency is realized.