Harman XXV low draft adjustment

[kzad]

I'm trying to set the low draft on a friends xxv, but the the stove is not alternating between high and low, the draft stays exactly the same. The lowest I can get it is .6. I'm using a dwyer markII manometer, and have done this on my own advance in the past. The advance has two distinct levels, low and high, and I was was able to set the draft properly. He called his dealer, who called harman, who said this is normal.... which contradicts their own manual, and the way mine runs.
Any one ever run into this??

 

[lbcynya]

Not sure about the Advance, but on the XXV low draft and high convection blower alternate, when draft is on low, convection is on high. The difference for draft is negligible. My draft is off the charts as well. .6 or so as well. Draft adjustment screw is worthless, just turn the draft pot all the way ccw and be done with it. I suppose there are mechanical methods of reducing draft, but nothing I'm comfortable modifying while under warranty.

 

[Lousyweather]

sometimes it will "peg out" even on the low draft mode.....actually very common......maybe more often than not.

 

[lbcynya]

sometimes it will "peg out" even on the low draft mode.....actually very common......maybe more often than not.

So what do you do (if your a draft fanatic like me)? Restrict the exhaust? I already have the intake covered at 50% to get rid of the angry flames from he!!, but that's not a long term solution IMO.

I say this also, because I believe excessive draft is also contributing to the woofing (low frequency vibes around 10-20 Hz) and "vibrating" flame (about mid fire) which is equally as unenjoyable as an angry flame, especially since they happen at the same time. It's like it's pissed off and yelling at me on top of it.

 

[jmart]

sometimes it will "peg out" even on the low draft mode.....actually very common......maybe more often than not.

What does peg out mean?
It just so happened that I went to my dealer today in hopes to borrow his draft meter.
I did the install myself so I wanted to check the set-up per Harman's manual. He told me
that there was no need and that they never check for proper draft when they install pellet stoves.
He's been around for years so--I don't know.

 

[lbcynya]

sometimes it will "peg out" even on the low draft mode.....actually very common......maybe more often than not.

What does peg out mean?
It just so happened that I went to my dealer today in hopes to borrow his draft meter.
I did the install myself so I wanted to check the set-up per Harman's manual. He told me
that there was no need and that they never check for proper draft when they install pellet stoves.
He's been around for years so--I don't know.

I thought the same thing too. Why aren't the professionals checking draft? Fact is, on an XXV at least, the draft adjustment screw does so little that why bother to check at all. I think full ccw adjustment resulted in lowering the low draft from .62 to .58 whoopee. Set it at mid point and forget it is "safe" but not accurate. Harman needs to refine the way draft is adjusted on the stove, but I'm no stove scientist, so I can't comment on how they'd do that or if it's even practical to do so. Obviously they thought it was important enough to mention in the manual, but the fact that their numbers are often exceeded with no reasonable way to bring them in line baffles my mind.

 

[kzad]

The manual says that too high a draft will result in lost efficiency, but they give you no way to set it correctly?? My 7 year old advance works exactly as the manual says it should, and I was able to set the draft to spec.

 

[lbcynya]

The manual says that too high a draft will result in lost efficiency, but they give you no way to set it correctly?? My 7 year old advance works exactly as the manual says it should, and I was able to set the draft to spec.

Correct. That's why I have 50% of my intake covered. Doesn't correct the draft, but it does allow the heat to dwell longer in front of the heat exchanger since overall air volume is reduced. I'm not suggesting anyone do this because it's just a band-aid.

Only other solutions are a lower rpm combusion motor, less efficient combusion fan, both or?

 

[tonyd]

The woofing can also be caused by a bad hopper gasket. I also had the intake port restricted when I found a piece of the hopper gasket not in place. Fixed the gasket and no more woofing. HTHS

 

[lbcynya]

The woofing can also be caused by a bad hopper gasket. I also had the intake port restricted when I found a piece of the hopper gasket not in place. Fixed the gasket and no more woofing. HTHS

Hopper itself has an upper and lower gasket, which one did you fix?

I put aluminum tape over the lower seal area to temporarily see if the lower gasket was the issue and the woofing persisted.

Top gasket is a real PITA to get to, so I haven't done any sealing of that one... Grrr.

I also used a small straw to create a leak in the hopper fill lid gasket and this didn't change anything either.

 

[tonyd]

Not the lid gasket,It was the hopper gasket. My stove was woofing until I resealed the hopper gasket. No tape no more. No woofing.

 

[lbcynya]

Not the lid gasket,It was the hopper gasket. My stove was woofing until I resealed the hopper gasket. No tape no more. No woofing.

you're talking about the gasket at the bottom of the hopper around the area where the pellets fall into the auger, right?

My gasket seems properly seated, how did you fix yours?

 

[PJPellet]

Not the lid gasket,It was the hopper gasket. My stove was woofing until I resealed the hopper gasket. No tape no more. No woofing.

you're talking about the gasket at the bottom of the hopper around the area where the pellets fall into the auger, right?

My gasket seems properly seated, how did you fix yours?

This has got me wondering too.

 

[Lousyweather]

sometimes it will "peg out" even on the low draft mode.....actually very common......maybe more often than not.

What does peg out mean?
It just so happened that I went to my dealer today in hopes to borrow his draft meter.
I did the install myself so I wanted to check the set-up per Harman's manual. He told me
that there was no need and that they never check for proper draft when they install pellet stoves.
He's been around for years so--I don't know.

I thought the same thing too. Why aren't the professionals checking draft? Fact is, on an XXV at least, the draft adjustment screw does so little that why bother to check at all. I think full ccw adjustment resulted in lowering the low draft from .62 to .58 whoopee. Set it at mid point and forget it is "safe" but not accurate. Harman needs to refine the way draft is adjusted on the stove, but I'm no stove scientist, so I can't comment on how they'd do that or if it's even practical to do so. Obviously they thought it was important enough to mention in the manual, but the fact that their numbers are often exceeded with no reasonable way to bring them in line baffles my mind.

a professional would, or should, check the draft on a new install, at least to set a baseline for future "checkings" of draft (possibly useful at a later date for service issues). We write the setting in the owners' manual which is left with the homeowner.

What I meant by "peg out" is that, many magnahelic's have an upper limit of around .5-.52 inches of water.....any higher draft would "peg out" the meter. The adjustment to lower the draft only varies the voltage to the combustion fan a very little bit, so, even after adjusting down to its stop, its often not enough to lower the draft to a point where the draft does not still "peg out".

And we dont "lend out" magnahelics. ever. You never know how some folks take care of and use lent out tools. Some people are great, but some arent.

 

[jmart]

What I meant by "peg out" is that, many magnahelic's have an upper limit of around .5-.52 inches of water.....any higher draft would "peg out" the meter. The adjustment to lower the draft only varies the voltage to the combustion fan a very little bit, so, even after adjusting down to its stop, its often not enough to lower the draft to a point where the draft does not still "peg out".

And we dont "lend out" magnahelics. ever. You never know how some folks take care of and use lent out tools. Some people are great, but some arent.

Thank's for the explanation Lousyweather.
As for lending tools, well I totally understand. I would have been fine with "no way!" We seem to be on good terms
so I did not consider asking to be inappropriate with him.
Anyways,after hearing his opinion on the draft meter, I was no longer inclined to ask.--Jerry.

 

[Lousyweather]

yea, Jerry, some people you lend tools to, others you dont....some folks just dont take care of things or use them inappropriately. The problem is, you never really know how that person is until it's too late.......they always return them either telling you it was broken when they got it, or its fine when its broken. And this same person wont of course buy you a new one. Long and hard lessons Ive learned doing this, to the point of not lending them anymore.