draft reading how important is the location where tested???

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lime4x4

Member
Hearth Supporter
Nov 18, 2005
134
Northeast Pa
Okay after doing some more research on the operation of my magnum stoker i come to find that the dealer took the draft reading at the wrong place.The manual says to take flue draft reading atleast 6" BEFORE the barometric dampner will the tech the dealer sent out took the reading about 30" AFTER the barometric dampner.I wonder if that is why the stove runs so chitty when setup to harmans spec of .04 draft reading.Would there be such a change in draft if the reading is taken after the barometric dampner? Or i'm i going in the wrong direction here? Currently bidding on a draft meter on ebay cause i really don't trust them anymore..Esp since the tech had no idea how to setup the stove to begin with and there suppose to be harman trained.This is the ebay page for the guage it does show .04 correct?
(broken link removed)
 
You are correct, the diagrams on page 9 & 10 of the magnum stoker manual show the draft being metered between the stove and the barometric damper. The installation looks like the damper is almost sitting on the stove. Is it possible to get a probe in before the damper? It looks like it's needing a short length of pipe before the damper just to be able to insert the meter probe. Also, did the tech check the draft in the firebox to balance it?

PS: If you buy the used meter, it might help to compare it's readings with a good one to assert it is working correctly and to establish its accuracy.
 
The dampner is located on top of the stove but i can add a short peice of pipe..The other thing is the tech made the adjustment with the stove running.The adjustments should be made with the stove in pilot mode.And yes he did adjust the firebox pressure as well.The restrictor plat must be almost totally closed to obtain .04 but that was with the stove burning on high when the tech did it..I'm thinking it should be done with the flue warm and the combustion motor off.If u take a flue draft reading with the combustion fan running that will change the draft reading.My only delemia is do i really want those guys back out there again.It was clear the first time they were there that they didn't have a clue as to how to setup the stove..
 
hey if you do win the auction I have the instruction page you would need. I can scan it and e-mail you If you loose the auction. I would be willing to send mine to you for a week to setup your stove
 
lime4x4 said:
Okay after doing some more research on the operation of my magnum stoker i come to find that the dealer took the draft reading at the wrong place.The manual says to take flue draft reading atleast 6" BEFORE the barometric dampner will the tech the dealer sent out took the reading about 30" AFTER the barometric dampner.I wonder if that is why the stove runs so chitty when setup to harmans spec of .04 draft reading.Would there be such a change in draft if the reading is taken after the barometric dampner?

Of course, there would be a big difference! The chimney on the upside of the baro would have a much higher draft since it was pulling in a lot of room air - that means that air is moving faster which in your case = a higher reading.

So draft should always be taken "south" of the baro. This seems fairly obvious, but then again I'm looking at it from afar! This would be like using a transformer to step down voltage, but they taking the volts on the top (higher) side of the transformer......well, it's xmas so we can't be too cynical....
 
Like i said the tech had no idea what he was doing.I think it was the first time using a draft meter.my main issue with this dealer is that they don't seem to have a clue as to what there doing.I currently have the dampner directly attached to the stove but it's not a big deal to install a 10" section of pipe below the dampner then make the adjustments and then i'm sure this stove will work as described and to my satisfaction.
 
Lime keep us updated, like I said my magnum was suposed to be in 2nd week of Nov., 1st week of Dec., 2nd week of Dec. It's on the truck and should be in any day!!!!!and I am still waiting . Glad to see there is light @ the end of the tunnel.(Hope its not a train) Heading to the coal/stove dealer tomorrow and I want an honest delivery date. Seems to me they are going on my list with realestate, insurance, car dealers, pool salesmen etc............ Merry Christmas Jimmy
Wife is COLD........
 
lime4x4 said:
...dealer took the draft reading at the wrong place.The manual says to take flue draft reading atleast 6" BEFORE the barometric dampner will the tech the dealer sent out took the reading about 30" AFTER the barometric dampner.I wonder if that is why the stove runs so chitty when setup to harmans spec of .04 draft reading.Would there be such a change in draft if the reading is taken after the barometric dampner? ...
(broken link removed to http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=7574999432&sspagename=ADME:B:AAQ:US:1)

Yep, there is your problem. Kind of goes back to what I mentioned in my earlier post. These gauges measure differential pressure, not necessarily air flow through the stove. If the baro damper is in front of the gauge, it is acting as an inlet restriction and allowing you to pull more vacuum and throw the reading off.

That gague on e-bay looks like the hot ticket...assuming it works. I'm curious why the photos don't show the needle at 0? Maybe he has it hooked up already. If the bidding goes south on that or you decide it is just taking too long, you could make your own gague out of a 3-4 foot length of clear plastic tubing. Just add a little water with food coloring and bend the tube into a "U" shape. Presto - instant manometer. Hook one side of the U up to the stove, leave one side in open air. You will be looking for the stove side water column to be just under 1/16" higher than the open air side. 1/16" is about .06" of "draft". You can make the manometer more sensitive but that requires more detailed instructions...if you are interested, I can post on how to set it up

Corey

PS - it does look like the gauge measures in hundredths as the seller says, but hundredths is ".04" not ".004" as he says...".004" is thousandths.
 
Hey Craig can u do me a favor and ask your harman rep buddy what is the correct way of setting the draft on a magnum stoker? The manual says when it's in pilot mode but when the stove is in pilot mode 2 things happen it runs for a short time then shuts off for a short time.Currently have it set to 4 min on and 12 min off.I'm assuming to make all adjustments with the combustiion fan not running just want to make sure..
Thanks John
 
Hey Lime
I would suggest testing it while it's cold, test the draft in the flue to set your barometric damper and right below the front door there is a set screw that you can take out and check the draft of the firebox. having a .03 coming from your firebox in a cold stove is very good. Remember as the flue heats up your draft will get better.
 
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