Jotul f500 secondary burn

[Setter]

We have a jotul f500 that was installed in our camp in Maine in 2000 , my parents have spent the summers there for the past 20 years and only use the stove to take the chill off of the house in the morning’s and the evenings ,so the stove has never been run as it was intended too . The past couple of years I’ve been spending a few days there in late October and have been trying to get a long burn but can only get a couple of hours out of it , the primary air control slows the flames slightly, but know where near the lazy flame that I get from my f400 that I have at my own home in Ct , there is no secondary burn as well . I’ve checked the doors and ash pan gaskets for leaks , as well as doing a smoke test to look for leaks in the stove it’s self , when doing the smoke test I’ve noticed the only place that air is drawing in is through the secondary air inlet in the rear of the stove . After trying different species and size of wood and not getting different results I plugged the secondary air inlet with tin foil and the stove acted like my f400 a very lazy flame with a secondary burn coming from the tubes on the top of the stove. I’m trying to figure out what I have to do to fix this stove properly as it wasn’t intended to run with the secondary air inlet blocked . Just a little info ,the chimney is 8’ of double wall inside the house transitioning to 12” of triple wall outside, and the stove was purchased in 2000.
thanks ,
Eric

 

[begreen]

This is a little confusing. I thought that there was only one intake port on this stove, like the F400. Are you saying there is a second port in addition to the outside air intake on the stove? The description sounds like insufficient draft. Can you describe the flue system in detail from stove top to chimney cap including any 90º turns and the height of the chimney from tee to cap? Is the exterior chimney 8" ID?

 

[Setter]

This is a little confusing. I thought that there was only one intake port on this stove, like the F400. Are you saying there is a second port in addition to the outside air intake on the stove? The description sounds like insufficient draft. Can you describe the flue system in detail from stove top to chimney cap including any 90º turns and the height of the chimney from tee to cap? Is the exterior chimney 8" ID?

Maybe I’m wrong , does the air that goes through the doghouse share the same port as the secondary air ? If they are the same I’m guessing that I’m blocking off all the air coming into the stove , I’ve taken apart the dog house and it seem to be functioning correctly .
The stove is vented from the top with 6”double wall in the house that is 8’ long and goes straight through the roof , on the outside of house it is a straight run of 6” triple wall that is 12’ long .
I may not have been clear the fire is uncontrollable ,and will burn out very quickly , we don’t get very high stove top temperatures, but flue temps can be up in the 1,200 degree range, and no secondary burn.
The only way I can get this stove to act like my f400 is by blocking the air port in the rear of the stove .
Thanks,
Eric

 

[begreen]

So high ceilings and about a 20ft flue system. That sounds ideal. How quickly is the air being turned down? What size are the wood splits? Has a gasket check been done on all the gaskets including the front, side and ashpan doors? If the ash pan is removed, is there any hard ash buildup at the back of the ash pan chamber? And last, if ash is all removed and wiped clean around the grate, are there any cracks in the base in the corners radiating out from the grate?

 

[Setter]

So high ceilings and about a 20ft flue system. That sounds ideal. How quickly is the air being turned down? What size are the wood splits? Has a gasket check been done on all the gaskets including the front, side and ashpan doors? If the ash pan is removed, is there any hard ash buildup at the back of the ash pan chamber? And last, if ash is all removed and wiped clean around the grate, are there any cracks in the base in the corners radiating out from the grate?

I checked all gaskets with the dollar bill test, used smoke from incense to make sure that all the gaskets and joints were well sealed and there wasn’t any air leaks , I will have to check for cracks in the base when I head up in the spring , but believe that I did look over the summer and didn’t see any .From your reply I’m assuming a base crack would cause air leakage ? Also the air port in the rear serves the primary air for the dog house and secondary air ?
Ive tried very large splits ,turned down air really early , ( which would have put my f400 out ) but it still burns hard with a high flue temperature.I’m guessing that I have an air leak in the base because if you block the rear air inlet with foil it behaves correctly. Would you say this is an accurate assessment?
Thanks ,
Eric

 

[begreen]

The F400 had one air entry point, at the OAK connection. If you cut off the air there you could snuff out a fire. I think the F500 is made similarly with regard to air supply. Maybe F500 owners can chime in here. @firefighterjake I think you tried this in the past?

Cracks in the base can mess up the burn. To inspect, clean out all ash and wipe down the area surrounding the grate. If that is not the issue then perhaps the fire is not getting hot enough or the air is not getting turned down enough. Turning down the primary air makes the vacuum created by draft pull air through the secondary manifold. Another remote possibility in a cabin is that some critter made a nest in the secondary air passage.

 

[Setter]

Thank you very much for explaining how the intake air system works , I’m going to look for cracks in the base when I get back up there this spring , I’m feeling like that is the problem . Thanks for all your help.
Eric

 

[begreen]

Has the ashpan door been used to supply the fire extra air when starting a fire? That is the prime culprit for cracking the stove base.

 

[Setter]

It may have , a lot of different family members have used that stove over the years,you never know what might have happened .
Thanks

 

[MR. GLO]

look at the manual for that particular year/model it will have an arrow where the secondary air enters. some models front behind the air inlet and some with pans have them in rear. Try 90 percent and let us know if thats good. I think its like a flashfire lever on old jotul 118cb. so watch for creosote after. measure draft.

There is an article on the bungalow effect.

i have tried different wood, chimney caps, etc just like you. but once i turn air inlet down for the slow flames i get smoke out chimney. my last option is damper.

http://www.gulland.ca/florida_bungalow_syndrome.htm

 

[Setter]

Unfortunately my manual does not have schematic of how the air flow works , I’ve looked online and can’t come up with anything. I do know that there is an intake in the rear of the stove but not exactly sure where the air flow goes from there. Thanks for posting that article it was interesting.
Eric

 

[bigealta]

Good bungalow effect article. Thanks

 

[MR. GLO]

Unfortunately my manual does not have schematic of how the air flow works , I’ve looked online and can’t come up with anything. I do know that there is an intake in the rear of the stove but not exactly sure where the air flow goes from there. Thanks for posting that article it was interesting.
Eric

one version doesnt show it...i think the cat version below does...here are some examples.