Jotul F600 and water coming down my chimney

[Sealcove]

I just discovered an unfortunate problem with my 2008 Jotul F600. Apparently water has been coming down my chimney in the non-burning months and reached a point where I found serious corrosion. I always pull the interior chimney off each fall for cleaning and inspection, and the issue was not evident a year ago, but today it was depressing. Here is what I found:

The collar that attaches the stove to the chimney is done. Heavy corrosion on the inside that the bolt holes had cracked. Significant rust and corrosion on the back inside of the stove, to the point that I can readily scrape up layers of mushy metal. The wool insulation over the interior top plate was soaked with ash and moisture, and the plate below was cracked in several places. There is also evidence of rust in other places along the back (had been concealed by heat shield) and on the rear bottom of the stove. Basically, I am guessing that the stove is going to need a partial rebuild with some substantial parts required.

My chimney is all vertical with no bends; 8' of interior double wall and then almost 20 feet of excel exterior pipe and an excel cap. The chimney and cap all look to be in excellent condition and there is no other source for the water but down the pipe from the top. What is vexing is that I had a Lopi stove in the same spot and configuration for 8 seasons without issue, and that stove now has 5 more seasons in my shop with the same kind of chimney setup and there is no evidence of water issues in it (it also hardly ever gets used).

Is this just a reality of cast iron versus steel? I assume that if I rebuild the Jotul I will be in the same boat in another 5 years unless I prevent water from getting in there in the off season. Any thoughts on a fix? Cap the chimney when burning season is over? Does anyone have any experience with doing a Jotul rebuild? Seems like a royal pain given that all of the fasteners look to be badly corroded, so I am assuming that everyone bolt is going to be a project.

 

[begreen]

Boy, that sounds like a bummer. Were their unusually strong wind-driven rains this summer in your area? Or was it one particular storm?

It sounds like you have a first-class setup. The water problem has nothing to do with the type of stove, but the damage done will be greater in a stove with more parts sitting in water. Thank goodness this wasn't a stove with a bypass and a cat or reburn system like a VC stove. Get everything dried out. Pull the top off, spray kroil or PB blaster on the rusted bolts and be prepared that some will snap off. It is not that bad though. They drill out pretty easily and can be retapped.

 

[Sealcove]

Thanks for that info. I think I can at least see what parts I am likely to need, so I will get those ordered from the shop tomorrow. Of course I am bound to discover more, but at least it is only early November.

 

[Sealcove]

So I still have the interior double wall pipe unhooked as I wait for a new collar for the stove. I had sealed the chimney exit into the house with a plastic bag and some tape, and today we got a moderate amount of rain, but not too much wind. There is 1/2 to 3/4 of a cup of water collected in the bag, so quite a bit of water has been getting to the stove. It has to be from the top, though I plan to verify that by covering the cap on the next rain event. Assuming that is correct, perhaps I have a problem with my Excel cap? I guess I will need to take a good look at that and find out. Baring that, does anyone know if you can get a cap with a larger brim on it or are we talking about something custom?

 

[Sealcove]

For anyone who might be following this, I was completely wrong about it being water from the cap. I sealed that up with a bag before the next round of rain, and still have water at the base. After closer inspection I now realize that there is water getting in at the junction between the exterior and interior chimney. I am hoping it is an issue with the collar, even though that looks well sealed, and not the metal roof. Either way, I need to pull the entire chimney for inspection tomorrow and hopefully I can find a permanent solution. Too bad it added some serious wear and tear to my stove before I caught it. It certainly does not appear to be a stove killer, but it can't have helped its lifespan.

 

[Holiday]

That was my thought as well, is the storm collar sealed properly or is it getting in there and running down the chimney. Not sure where else it would actually get inside. If the flashing was leaking it shouldn't get to the chimney I believe.

 

[Sealcove]

Sometimes with the metal roof and 12/12 pitch, snow comes sliding down and whacks the collar. I inspect it a couple of times a year, but I am betting that there is something I am not seeing. Perhaps I need to find a more durable adhesive/sealant for that.

 

[Holiday]

Might want to put snow stops above the chimney. I used silicone on mine. Only been up a year though.

 

[blades]

Flashings & storm collar are where your problems are originating. Butyl type calk is about the best I have found for areas that have a lot of thermal expansion/contraction like metal roofs and external flue interfaces, and make sure you have a good seal all the way around the storm collar.

 

[Sealcove]

I think as Holiday posted, I need to figure out a stop or cricket to protect the collar. I have been letting snow whack it and I am sure it slowly breaks the seal even if i can't see the failure. I was hoping to avoid more fasteners through the metal roof, but clearly I need to do something.

 

[Chris_Up_North]

This season was incredible. I'm in western Maine and we had some insane driving rain this year. Had a similar problem on a couple days with driving rains pushing creating a few drips of water down along the edge of the "stink pipe" (4" PVC vent for the septic tank). This put a few drops of water in one of the closets.

What type of roof do you have?

I've got painted corrugated metal, which is hard to flash in and that's what I believe created the problem. First, I went up there and tried to seal it with acrylic caulking. That didn't work. Didn't really want to re-flash the pipe with the usual boot, since it obviously wasn't working. On a whim, I tried using that As-Seen-On-TV FlexSeal. Put a whole can on it and PRESTO no more leaks, even with some of the crazy driving rains we had this summer. On the can it says "not for professional roofers", so good thing I'm not a professional roofer, otherwise it wouldn't have worked.........


I know none of that helps your problem, but I feel for you with the insane rain we had this year. I put on a chimney cap last season and now we don't get any water down the chimney. I don't remember the type of cap but it wasn't anything fancy. Just four tabs holding a small triangulated dome above the opening at the top of the pipe with a "spark arrestor" made of 3/4" or so SS hardware cloth.

Best of luck!

 

[Sealcove]

Yes, it was a crazy wet year and that would explain all of the corrosion in one season.

The roof is galvanized snap lock. The seams are elevated about 5/8", but they are more triangular in shape as opposed to a true standing seam. I took the entire exterior chimney off this morning, inspected everything and then reassembled it. After getting a good look at everything, I am now 100% sure the water was getting by the collar. I found a failure in that seal on the uphill side of the chimney; it looked good until I started flexing it and then I saw 3-4" where it was completely separated. I took a hose to the collar and just by spraying the pipe above and letting the water run down, I was getting water below the collar. The rest of the roof/chimney interface is in excellent condition, properly overlapped and sealed, and I see no evidence of water migration from that.

So in the end it was a very simple problem causing a bigger problem. With the chimney back in good shape, my next project is to install a cricket or snow wedge of some sort before snow arrives.

 

[Holiday]

That's good to hear you found the problem, now I'll make sure to check mine in the spring again.

I am trying lengths of angle iron screwed onto the seams uphill of the chimney. Looks kind of like a ladder on the roof. Should stop the snow from sliding but it will have to melt off. Not sure if a person would rather have it slide and have a wedge above the chimney or just stop the sliding.

 

[Chris_Up_North]

Yes, it was a crazy wet year and that would explain all of the corrosion in one season.

I found a failure in that seal on the uphill side of the chimney; it looked good until I started flexing it and then I saw 3-4" where it was completely separated. I took a hose to the collar and just by spraying the pipe above and letting the water run down, I was getting water below the collar.....

So in the end it was a very simple problem causing a bigger problem. With the chimney back in good shape, my next project is to install a cricket or snow wedge of some sort before snow arrives.

Excellent to hear. Waterproofing roof penetrations are a PITA. I used to work at a commercial roof membrane manufacturer (mostly low-slope EPDM) and penetrations and tie-ins were the source of over 95% of all roof leaks.

I'm looking to to put a snow diverter on my metal roof. Something like the below picture but not copper (not my house, just a picture from the innerwebs). I have "bumped out" array of three floor to ceiling picture windows with its own roof and it sometimes scares me when snow from the upper level falls and clips the lower roof on its way down. Do you know where I can buy some aluminum Ell or similar in our neck of the woods?

Thanks!

 

[Sealcove]

I don't know where to get aluminum. I ended up ordering a rather expensive wedge that Excel makes ($170). It has four fasteners a side and on a 12/12 roof it will be 3' wide and around 24" at max height. It certainly will shield the collar and through roof portion of the chimney from snow.