Ashes and air intake

[mj5001]

Hate to sound like an idiot but wondering if I should be cleaning out my insert every time I light a fire. Sometimes I let it go a few days and get a good 2" or more base of charcoal and ashes in there (probably should be all ash, granted). Does too thick of an ash base interfere with the fresh air intake? (Drolet 1400 insert).

I still don't know how they get fresh air into this, I've never seen any "opening" in the actual firebox so to speak. I did remove a couple of covers for exterior fresh air intakes that are meant to feed outside (but haven't done it yet).

Thanks for any help.

 

[BobUrban]

Read your manual if you have one. Most, if not all, modern EPA stoves run best with a bed of coals and ash to help with insulation. Most experienced 24/7 burners never clan the stove completely until spring and leave an inch or two of ash in the bottom during their periodic clean outs weekly or so. All that said, you are likely doing yourself a disservice on multiple levels by cleaning out the stove between burns if you want continuous heat.

 

[mj5001]

Ok thanks, for some reason I started having some backdraft problems when all these arctic temps hit here in Indiana last week. Didn't get a chance to clean the chimney last fall because of a bad foot. Going to take out the baffle this weekend and do what I can. The colder the outside air, the BETTER the draw, right?

 

[coaly]

Yes, the more temperature differential between outdoor and inside flue the more "draw". The rising more buoyant lighter air and gasses in the flue create a lower air pressure in the stove. Atmospheric air pressure actually pushes into the stove intake. So as low pressure areas from storms moves over the stove, you have less air pressure pushing in, and need a larger intake area (farther open) for the lowered air pressure.

 

[mj5001]

I want to ask one more thing. I have a Drolet 1400 insert and although I've looked at their drawing and other stove drawings, I'd like to know "where" in a typical stove the fresh air comes in. My firebox is completely sealed, yet I have an air inlet lever on it. I don't (visibly) see where air comes in -- is it under the firebrick usually?

 

[coaly]

"Typical" stove with secondary combustion tubes needs preheated oxygen that normally comes in the front and is heated in a channel of sorts on the firebox bottom and up the back before coming out of the holes in the tubes. The design requires the air to be heated over 700* to prevent chilling smoke so it ignites.
Page 15 of manual; figure 2.5 shows your inlet opening on the right side behind faceplate that can have an outside air intake duct attached. The adjustment rod connects to a what looks like a flat lever that opens and closes the inlet passage.

 

[mj5001]

You're great, yeah after posting the question and looking at my secondary tubes it occurred to me that's the air source -- only thing in there with holes. Actually, they look pretty clean. Do people modify these in any way? I have a good setup but not optimal, adding a fresh air duct this spring (and thanks for that right side info, there are actually 2 inlet covers one on each side, are you saying only the one on the right side is "active"? both are?). The secondary tubes look clean -- I could use better fuel this season but do people sometimes drill some of those holes a little larger?

Thanks for the info -- now I feel like I get what's going on with this thing. Wonder if my tubes are stainless? They come out easy enough -- can they take a water wash I wonder? pressure wash?

 

[coaly]

I would not modify it any way. I don't use secondary burn stoves, but added secondary combustion in ways other than tubes to older stoves built before the secondary technology was used. The number of holes is calculated for BTU and changing them can cause the air to move through the preheating chamber too fast, cooling it causing the secondary ignition to stop. Usually stainless, no idea if they ever require cleaning.

 

[Valhalla]

Living in the secondary air, burn environment should assure that the tubes are automatically burned clean.
The tubes on my Jotul Oslo 500 seem to be stainless and are self cleaning.