Vermont Castings Intrepid w/cat gets too hot too easily. What am I doing wrong?

[Woody Stover]

I agree with several other posters who think you may have one or more air leaks.
That door gasket set-up looks strange, but since no one has mentioned it, I'll assume that's the way it's supposed to be...
To check for air leaks--In a darkened room, shine a bright flashlight around the inside of the stove toward the seams. Have another person look at the seams from outside the stove as you shine the light on them. If light gets through to the outside, air can get in at that point. You can also use an incense stick to move around the seams/gaskets on the outside of the stove while it's burning. If the smoke gets sucked in, you've located a leak.

Don't get too discouraged yet. Hang in there, you'll figure it out. These are some of the things that make running a stove interesting.

 

[elmoleaf]

As jetmech said, get down and get your eyeballs looking up into the primary air opening at the back while shining a light inside the firebox towards that corner. On the 1303, a vertical tie rod runs near that area. Often the cement will drop out in this corner, which allows air straight into the firebox, without passing around the ashpan to the glass up front. Not sure if they redesigned that intersection on the 1308.

Also, make sure the secondary air inlet and temp probe is working correctly and intact.

However, I suspect you're getting a seam leak somewhere else. Remember there are more seams than just the gasketed ones at the front doors, griddle, and damper. I had a leak on my stove along the vertical seam between the front casting and side casting at the front left corner of my firebox. It took awhile to figure that one out...didn't show up by shining lights or anything. Only figured it out by when I realized that side of the hearth was always much hotter than the right side.

I'd try the incense stick trick with the stove running to look for leaks. If your stove was ever moved by lifting from the top or side castings or tilted in a similar manner (versus only supporting/lifting from bottom casting), that will typically break the cement bond between the cast iron plates and allow air leaks.

Also, remember performance is never constant. Exceptionally dry wood and days with strong draft (versus warmer outside temps, damp days) all tend to create a rip roaring firebox.

 

[afptl]

OK. I laid on the floor and found the "secondary air spot". I think. It was in the center back of the stove. It looks like it has a thermostat thing attached to a metal plate. The metal plate looks like it will go up and down. Right now the stove is cold and so it was all the way open. I guess I will have to make a fire to see if it closes up or not.
that's the picture I attached.

 

[afptl]

Alright, I think I found something!! I turned out all the lights and shined a flashlight around the seams. When I got around the top, near the + and -- skinny damper control, light was shinning in the firebox This is when the CAT is off. there has to be a leak there!

So I am thinking, get some furnace cement and seal up that leaky place! Will try to get some after church tomorrow. Any special tips for doing it?


Does anyone know how I could test the center back underneath damper thing without building a fire in it? If I used a taper lighter like you light a gas grill with would I damage the thermostat?


REALLY appreciate all the help!! I guess I am really going to know a lot about this stove before it is all said and done!


Also, I think the air control damper in the 1308 works like the 1303.

 

[afptl]

Hubby brought home tube of Rutland furnace cement. I put it anywhere I thought might need sealing and checked with a light again. Now I do not see any light. Letting it cure overnight and will try a fire tomorrow afternoon. I'll keep you posted. If I don't get it too hot, I'm going to slide the mirror under it and see if that air control in the center back makes any changes. I can't figure out how to test it without making a fire. Hope that works, getting tired of playing Nancy Drew detective!

 

[BrowningBAR]

Hubby brought home tube of Rutland furnace cement. I put it anywhere I thought might need sealing and checked with a light again. Now I do not see any light. Letting it cure overnight and will try a fire tomorrow afternoon. I'll keep you posted. If I don't get it too hot, I'm going to slide the mirror under it and see if that air control in the center back makes any changes. I can't figure out how to test it without making a fire. Hope that works, getting tired of playing Nancy Drew detective!

Be sure to do a few small fires to cure the cement properly. Otherwise the cement will crack, crumble, and break away within a few weeks.

 

[afptl]

OK. On my second small fire to break in the cement. I'll keep everyone posted as to how things go. I noticed when I was crawling around on the floor that the gaskets around the glass looks rough. Will call tomorrow to see about replacement parts.

 

[afptl]

I think we found the problem!! Had 2 fires in the stove yesterday, and the one last night the stove worked pretty good. Had it putter along last evening, then it worked up to 650 degrees. I cut the draft/air flow switch and it worked!! The temp dropped and fire responded to lack of air.

I feel pretty comfortable saying it was the place near the thermostat where the caulking stuff came out. Probably because we have a long driveway that is gravel. Maybe the ride home was a little rough??

I tried to show some pics where I repaired it with furnace cement. It was a little tricky because I did not want to disconnect or move the stove. Used a mirror, a Popsicle stick and my hand to put it where it needed to be. Not the neatest job, but I was trying to fix not look pretty!

I feel 100% better about the whole stove thing! I just want to thank everyone who took the time to post and offer suggestions.

I looked last night up under the stove with a light and mirror when it was about 550 degrees at the center back air intake. Didn't seem to be moving any. Does anyone know what temp that thing is supposed to shut down on?

I am probably going to check out the cat too, just to see the condition of it.

Good thing we have her going good now, they are calling for an ice storm here. Just in case the power goes, at least we can get some heat and cook on top.

What is the ideal temperature to be running this stove at now that it's back in business?? I know to flip it to CAT at about 450-500 degrees. Where do you run your thermostat damper part? (skinny silver part/handle on top)

 

[elmoleaf]

The gap you sealed shouldn't make any difference. That gap doesn't let any air into the firebox....that point would simply let air into the reversable flue collar area, which is outside both the firebox and the refractory chamber area. In any event, the rod from the damper handle passes through underneath where you sealed and is going to let some amount of air into the exhaust stream anyway.

The secondary air flapper you photographed should be open when the stove is cold, and closes down as the stove heats up. It is connected to a bimetallic thermostat and metal probe that sticks into the refractory chamber/exhaust stream immediately after the catalyst. As long as the flapper is still hanging by the metal rod from the bimetallic coil (and assuming the probe hasn't eroded away over the years) you should be OK with that aspect of the stove.

If you still have temp issues, make sure the damper gasket is intact and that the damper door seals securely when you turn the handle up.
Double check your glass gaskets, door and griddle gaskets.
From the outside of the stove, shine a bright light along the vertical seams where the front & back castings meet the side castings. You shouldn't see cement oozing from these or anything. You also shouldn't see an uneven reveal line at the joint indicating a warped casting or anything else that doesn't look normal.

It's possible everything may look normal, but the cemented seams between castings cracked open if the stove was lifted or tilted by lifting at the door/griddle openings, instead of from the bottom. I bought my stove used and that is exactly what I discovered. I had the stove outside and was washing it out (to check for cracked castings etc) with a low pressure garden hose. To my surprise, I saw water squirting out in numerous places, especially around the top casting. I ending up tearing the stove down and completely rebuilding it.

Normal operation with the cat engaged on my 1303 is anywhere from 500-650 F (accurate thermometer in griddle center), depending on the wood. Lots of small stuff makes the temp hard to regulate. I try to stick to 2-3 big splits if possible after a good fire is established (in other words, plenty of coals, firebox temp above 450f).

 

[afptl]

I also put some furnace cement along the edge where the reversible flue collar was on 3 sides. Not very heavy. We did flip the flue collar, but the gasket seemed fine. Just standing there with the furnace cement and just kept going with it.

When I looked inside the stove, I could see light on the top back of it. that's why I put the furnace cement there. After we put the furnace cement there, no light leaks. I still want to get some of the incense sticks to try to go around it more and look for leaks. Just haven't been to town yet to go to the store. It's about 15 miles to a big enough store to get them. with the price of gas, no frivolous trips. Has to be a combined effort.