Tarm Primary air adjustments

[lawandorder]

I have been getting stack temps of 500-700 degrees throughout most of the burn time. I am thinking that I am losing a lot of heat up the stack. I read a few posts suggesting adjusting the primary air which is located under the cover and is done by turning in the bolt. When doing this i noticed that at no point does this bolt ever contact the primary air stop. Is this right?? Any help is appreciated.

 

[WoodNotOil]

If I remember correctly, it is a little confusing. There is a black knob and there is a black plastic nut like thing that keeps it set in position. The bolt should turn making the opening larger/smaller. You may have to loosen the nut thing first though. It sounds like you need to adjust it a bit. I got my temps below 400. I don't have turbulators yet. I hope when I add some chain turbs to get it even lower. Good luck.

 

[jebatty]

...stack temps of 500-700 degrees ...adjusting the primary air which is located under the cover and is done by turning in the bolt. When doing this i noticed that at no point does this bolt ever contact the primary air stop. Is this right?

If we're talking the same thing, there is an adjustable damper on the draft fan under the top cover. WoodNotOil is right, this is adjustd by a black knob and nut. There also is a stop nut on this adjustment, which adjust the range of adjustment made by the knob. It is possible to adjust this so that the damper can be fully closed to fully open. Look closely and you will see how to do this. It took me awhile to notice this, as I had to damper the draft down quite a bit to get by stack temps into an acceptable range. My stack temps run 400-550 usually, with the higher temp on the initial burn, and also edging up as return water temp moves up.

My understanding, subject to correction, is that the draft fan damper setting affects total air, primary and secondary. The sliding knob adjustment on the front panel then adjusts amount of air which is bypassed to secondary. If the slider is all the way to the right, almost all air to primary and very little to secondary. And if all the way to the left, much more air to secondary and little air to primary. I just set this in the "middle and forget it," although depending on your wood and MC, you find a somewhat different "set it and forget it" setting.

Your natural chimney draft will always pull some air through the draft fan damper, even when the fan is off, but if your natural draft is very strong, you may have to damper down the draft fan quite a bit.

 

[flyingcow]

Well I don't have the same model tarm as you, but I've been able to average about 400 stack temps. This does have the turbolators. My wood has very low MC, so my primary is 50% and my secondary is 75%. My stack temp just started to climb, so I'm assuming it's time to do a cleaning. Been burning two weeks haven't touched a thing. At least it's going to be above zero today.

 

[twitch]

lawandorder -
I have a Solo Plus 30, the new Scandtec model, and I noticed the same thing with regards to the primary adjustment. I loosend the nut and screwed the adjustment bolt all the way in, and it didn't even come close to touching the damper arm. It's almost as if it wasn't installed correctly. My wood is far from being well seasoned, so I don't get really high stack temps, so I haven't tried to remedy it. I'm going to get started earlier this spring with cutting / splitting, so hopefully I'll have better wood. When it's just about time to shut it down for the season, I'm going to take the primary fan off, and try to see what's going on. Sorry no solution offered, but I'm in the same boat.

 

[jebatty]

I loosend the nut and screwed the adjustment bolt all the way in, and it didn’t even come close to touching the damper arm.

Unless the new model changes things, look again at the whole setup for the damper. I thought the same things as you say, but there is a second adjustment. Consider the black adjustment knob/nut as the fine turning, but there is a second nut adjustment (from memory, not looking at the damper right now) that also can be adjusted to the point to allow the damper to be closed completely by the black adjustment knob/nut.

 

[lawandorder]

I have the new Scantec model as well and ive looked and looked and aside from feeling pretty stupid, I cannot figure out any way that this bolt touches anything. Its just a bolt with a lock nut. I can turn it all the way in or all out and I get no change in performance or burn. It is just a bolt that goes through a piece of steel. No holes, no connections that I can see anyway. Stack temps still reaching 700 plus during the burns.

 

[Rory]

I'm with you guys, can't see that it does anything. In fact, I was going to pose this question myself, but I'm trying to pace my pleas for help.

 

[Gene C]

I had experienced the same problem with my Tarm so I adjusted the stop on the fan damper shaft. I started by shutting off the electric to the Tarm to eliminate the possibility of me grounding out the control board while I was close to it with my wrenches. I then turned the "Black adjusting bolt" all the way in till it bottomed out. Now you loosen the nut holding the damper stop on the shaft and move the damper stop till it contacts the tip of the "Black adjustment bolt" and then retighten the locking nut on the shaft. Now back out the "Black adjustment bolt" (Counter-clockwise). Turn the electric back on and start the blower motor. At this point you just run the adjustment bolt back in till it contacts the blower damper stop. Now you have a full range of adjustment that you can make.

 

[twitch]

Gene C -
That's what I thought I'd have to do, but haven't got to it yet. A couple other things:

I noticed that my fan damper never completely opens. When the fan is on I can open the damper even more by hand. I wasn't sure if this was the way it was supposed to be, so I haven't done anything with it.

When I have the secondary air close to the right (less secondary air) the fan sometimes makes a bit of a noise, almost like a window fan would make if the wind is blowing against the flow of air.

Is anyone else experiencing these things with their Tarm?

 

[Gene C]

My blower doesn't open the damper all the way either and obviously that isn't a problem for us. Its making more than enough air. (I think that Tarm's factory setup of the adjustment screw was based on it being full open and not from the full shut position.)
I have noticed the noise from the blower as you have explained but I never have to run mine to the extreme right now that I'm burning seasoned firewood (3 years dried... almost too dry) I'm actually running to the extreme left on the secondary adjustment.

 

[dirttracker]

Twitch, the damper won't ever be fully 100% open, the airflow from the fan has to act against the weight of the damper to open it. With the stop turned all the way out it should open 80 - 90%. I also burn wood that is less than optimum MC, it takes -me a little longer the get the fire going, but once things are up and running I get good stack temperatures (500 - 650 F). The wood I burn is elm that has been standing dead for 3 - 4 years, but was just cut and split late last year and early this year. I have 500 gal of storage, so the Tarm has time to fire long enough to get the fire box good and hot and dry out the wood. My Tarm makes the same whining noise with the secondary air most - all of the way closed. I think this is normal, probabaly just turbulance somewhnere in the air passage or a characterisitc of the fan.