Jotul Firelight 12 Modifications

[RobOnBusiness]

I inherited my dad's old place with a Jotul Firelight 12 in it, with a short horizontal stub of a flue connector before it disappears into the wall and into a 30' tall double walled, boxed-in chimney pipe. He must've always had a hard time getting dry enough wood, because I never saw him able to operate it without the ash door open. When I took over, I wanted to be able to get off the oil furnace completely, and just use the stove, but also found I always needed to keep the ash door open. I took the rear burn plate off and found no catalytic converter, and some refractory blanket missing. I then discovered there was no fresh air feed designed to the grate via the ash box, only the air wash down the doors, so I cut two additional holes in the stove floor directly below the existing holes at the fresh air slider, which lead to the ash box, and engineered a couple of extra doors for those on the slider. Everything worked great after that, but I'm wondering if I can further modify the stove to optimize secondary burn without a cat. The secondary burn setup on the F600 looks great, but not sure how best to incorporate something like that into the Firelight 12. Any feedback would be welcome. I've included some pics of the air feed mod.

 

[Isaac Carlson]

I'm not familiar with that model of stove. Does it have burn tubes? They are not too hard to add.

 

[RobOnBusiness]

Thanks for offering that! It so happens I've recently been seriously thinking about doing just that - no, it doesn't have any secondary burn system. I've been planning adding some tubes since I saw a few videos on YT about guys who had successfully done it, to a much improved burn and efficiency. I then experimented rudimentarily by cracking the top lid open a bit, holding it open with a small piece of wood, and shutting the main air supply damper off. I now often get flames roiling around in the firebox, burning the cooked wood vapours. So thanks - adding tubes tied into the outside air supply is my next project! I've never stick welded stainless before, but I imagine it can't be too much different from regular.

 

[bholler]

Thanks for offering that! It so happens I've recently been seriously thinking about doing just that - no, it doesn't have any secondary burn system. I've been planning adding some tubes since I saw a few videos on YT about guys who had successfully done it, to a much improved burn and efficiency. I then experimented rudimentarily by cracking the top lid open a bit, holding it open with a small piece of wood, and shutting the main air supply damper off. I now often get flames roiling around in the firebox, burning the cooked wood vapours. So thanks - adding tubes tied into the outside air supply is my next project! I've never stick welded stainless before, but I imagine it can't be too much different from regular.

That stove does have a secondary combustion system and it is a very poor one. Honestly I would abandon that stove and find something else. It really is one of the worst modern stoves I have seen. Certainly the worst jotul has ever made.

 

[RobOnBusiness]

It does have a catalytic combustor at the back, but the element is long done and gone. What suggestions do you have for a better stove with no cat?

 

[bholler]

It does have a catalytic combustor at the back, but the element is long done and gone. What suggestions do you have for a better stove with no cat?

Pretty much any modern tube stove will work far better than this stove ever did.

As far as new budget stoves look at drolet. Higher end stuff quadrafire regency Pacific energy and many others

 

[RobOnBusiness]

Thank you!🙏

 

[Isaac Carlson]

No need to use stainless if you do decide to keep it and add tubes. You can use regular steel. It's easier to work with and should last a long time.

 

[bholler]

No need to use stainless if you do decide to keep it and add tubes. You can use regular steel. It's easier to work with and should last a long time.

Regular steel for the tubes doesn't hold up very long. It's fine for the manifold. But I wouldn't waste the effort on this stove

 

[Isaac Carlson]

This is one I refurbed a couple of years ago. It was grossly overfired from the previous owner and was in sad shape. It never had tubes in it. I cut out all the old damaged steel and turned it into this. The primary/air wash supply comes from below the door, out to the sides, and back in across the top for maximum preheating. The secondary supply comes up the rear, out to the sides, and then forward to the air tubes. There are sliders under the stove that regulate both air supplies and can be closed completely. This stove burned very well and had very long burn times. I designed it to be spaced properly for firebrick, to reduce the need to cut them. I added heat shields and door gaskets. The owner wanted the air knobs left intact.

 

[Isaac Carlson]

Pretty much any modern tube stove will work far better than this stove ever did.

As far as new budget stoves look at drolet. Higher end stuff quadrafire regency Pacific energy and many others

Drolet makes pretty nice stoves.

 

[RobOnBusiness]

No need to use stainless if you do decide to keep it and add tubes. You can use regular steel. It's easier to work with and should last a long time.

Ah. Thanks for that - I've only seen people make stainless ones, so I appreciate that. I'm 66, and I imagine I might get tired of that stove before they erode away!

 

[begreen]

A stove in regular use can burn through regular steel burn tubes in as little as 4-5 yrs. Lopi learned this pretty quickly and had to switch over to stainless. Pacific Energy doesn't use tubes. The secondary air is incorporated into the stainless baffle system.

 

[Isaac Carlson]

Even so, I think it is wise to make them easily serviceable. The ones I make are held in with a pin or bolt.

 

[RobOnBusiness]

Even so, I think it is wise to make them easily serviceable. The ones I make are held in with a pin or bolt.

I agree. Also important to make allowance for different rates of expansion/contraction.

 

[Ashful]

As a former (and recovering) owner of three Jotul Firelight 12's, I'll second bholler's recommendation to dump that thing for scrap, and replace it with something newer and more reliable. These stoves weren't great when they were new, and cemented cast iron stoves can develop quite a few new problems at 30 years of age. Also, replacement parts fall between unobtainable and comically expensive.

 

[RobOnBusiness]

So, I've finally gotten around to designing and fabricating a secondary burn system for my Firelight 12 that I first modified with the addition of air piped into the ash box, that I first described above, with photos. I cut into the 2 fresh air plenums running beside the ash box, via the firebox floor. I welded up 2 columns that piloted into the cutouts I made, and welded flanges to their bases that bolted to the floor. Via trial and error, I tacked the crossbars and burn tubes in place, snaking around various angles and bolts in the top of the fire box. I used 1/8" wall 1x2" rectangular steel tubing, and 1x1" square tubing, welding with a stick. It works very well, and I can completely cut off all stove regulated air supply, letting the tubes suck a thermostatically controlled air supply from the main outside air supply. With the thermostatically controlled fresh air, I can walk away from the house without worry about overfiring. The butterfly valve control is designed so that if anything fails, it will default shut by gravity.

 

[Ashful]

Nice fab work. I like the fail-safe mentality.