difficulty with second burn on a thundra 2

[zakam]

Hi, i have a thundra 2 furnance and i have difficulty to keep the second burning working more then 5 or 10 minutes. as soon as i turn the ''key'' to low (around 145-150F on the fournace meter) everything start well but then like i said 5 or 10 mins laters it had loose all its warm the 2nd burning stop. anything i do wrong or is it normal ? its my 2nd winter with it and it been alway like that !

Thank for your help !

(am really sorry if my writting is bad, am french canadien and still learning english)

 

[laynes69]

How long has your wood been cut, split and stacked? Also, what type of chimney and size? It sounds like a classic case of wood that's not fully seasoned.

 

[cumminstinkerer]

@zakam I can't help much with the furnace but for just learning English you got your points across and I was able to figure out what you were saying. If it helps you can use google translate too help too, I did the same with spanish and you Fench Canuks at my previous job selling tractor parts, language can be a huge barrier but keep trying and use your resources. Good luck with the furnace.

 

[maple1]

What is the 'furnace meter'? Can you post pic of it? And 'key'?

Or, maybe someone with a T2 will be along and know exactly what you mean. But it's fuzzy to me.

 

[Highbeam]

Just read the furnace manual for the heatpro model, same thing but the next bigger model, and Drolet talks a lot about how to start this furnace and expect secondary combustion for about 50% of the burn cycle. They say that wet wood or insufficient warm up time is the usual cause unless your draft is out of spec.

 

[blades]

Second thing about tube type units is if you turn it too low too fast you lose your off gassing due to insufficient charring of the fuel. You need a good coal bed and just enough air to see just a bit of active flame above the coals ( best description I can give).

 

[zakam]

for the chimney its a 6'' diameter and 27' long my wood as ben cut and split about 5 or more year ago store in a shed all time, so if i understand i should do a ''pre brun'' with small stuff tu get an hot coal bed and then do the real one with a lot a log and get it going ? the 2 picture are the ''key'' and the meter

 

[brenndatomu]

Loading on hot coals usually does make things work a little better...but it really sounds like that wood really isn't dry...could it get good air flow in the shed there? Was it split, or in rounds?
Try burning some construction cut offs, 2x4s and the like (not plywood...and not treated wood either) or get a couple packs of those compressed sawdust firewood bricks to try out...add some 2x4s, or a few of the bricks to a load of wood (I put 'em on top)...see if it goes better for you. The ultra dry wood helps to average out the moisture content of the load, plus it will stay burning long enough to dry out the rest of the wood.
You will still be losing some efficiency due to the higher than preferred average moisture content of the load cooling the fire, and you will need to clean your chimney more often, as it will not burn as clean as it would with a load of fully dry wood...but doing this trick may help you get by until you can build up a good dry firewood supply.
Also, if you can scrounge used pallets from business's for free (many places give them away) you can cut them up carefully with a circular saw in a couple minutes to firewood sized pieces. The pallet wood is usually pretty dry and burns good...again, just mix some in with your firewood when you load.
The ashes will then need to be disposed of somewhere other than your garden or driveway due to the nails, but that's usually not a big hurdle for most people.
Just FIY, get yourself a cheap moisture meter to check your wood with...grab a chunk after it is room temperature, split it in half again, and then check the moisture in the middle of a freshly exposed face...should be under 20%
EDIT: Don't Tundras come with moisture meters now?

 

[Highbeam]

Pretty sure that digital readout is just your duct delivery temperature from the probe in the duct. Used to cycle the blower.

That’s not your flue or stove temperature.

 

[brenndatomu]

Pretty sure that digital readout is just your duct delivery temperature from the probe in the duct. Used to cycle the blower.

That’s not your flue or stove temperature.

That's true...