Seton and clones - Draft readings and exhaust temps when draft is closed (also overtemp kicking in a

[byrddogwi]

When my boiler, Seton W100, closes the draft around 180 degrees, my draft gauge still shows around .05-10 "WC. I would think that it should almost go to 0 or maybe .01-.02" WC. I have taken off the sides and sealed them and sealed the top. I have also put rope on the front door and on the draft. I don't have a draft inducer to do the Anthony leak test so this is about as good as it is going to get. I don't know how I would seal the bottom of the boiler.

Is this what you all are seeing?

I also noticed that when the draft is closed I have exhaust temps around 200-250 degrees. Is that normal also?

I also have a small issue of the overtemp aquastat kicking in a lot. I have the draft set for around 180 and the overtemp stat set for 200. The draft does close around 180 but almost every time it cycles off the overtemp kicks in later. Do I just need to lower the draft or is the draft I am getting after it closes the problem? I am guessing that it is still burning and it keeps heating up and kicks in the overtemp.

 

[mole]

Hi Byrddog,

This is my first post. My W-100 shows similar draft with the draft door closed as you get. I think that's normal - you don't have to have air flow to have a pressure differential.

When I first installed my Seton, the ash pan warped..I didn't have ashes or dirt in it at start up (my mistake). Anyway it leaked enough to make the temp climb steadily while it was cycled off. A peek in the door showed some glowing near the front of the boiler at the ash "hole" rather than in the back by the draft door. I sealed the bottom ash pan with silicone by putting globs on my fingertip and then reaching underneath it. It's a PITA reaching under there, you have to do some from the back and some from the front with a little stretching. Lesson learned: don't do it hot!! This leak caused a slow and GRADUAL temperature climb, rather than the usual 1-2 minute "spike" you see at the end of each cycle. The climb was only obvious under no-load conditions after I insulated my pipes.

When my boiler used to cycled off, the exhaust would cool to about 150F by the end of the closed cycle (about 3-7 minutes, depending on how hard it was running). With my new heat storage, my boiler doesn't cycle any more to speak of. It pretty much runs flat out (and much cleaner). When I shut it down now after a typical long, continuous burn, I now see about 200F to 250F on the exhaust for a while. So I know that the exhaust temp is realted to the boiler (refractory) temp as well as the amount of leakage. Bottom line is that mine leaks too, but I now realize that the idle exhaust temp is a function of the refractory temp as well as the rate of air leakage. I failed Anthony school...my leaks got worse when I put gasket material in. I'm going back for my Anthony GED once I finish getting all my new piping insulated. I, too, would be interested to hear what a "good" exhaust temp is on a tight Seton that has been running hard so I know what my goal should be. (I have a draft inducer, but I wired it so that it will only run with the draft door open.. so I can't do Anthony's vacuum leak check either without messing with the wiring a bit.)

mole

 

[ISeeDeadBTUs]

I probably have nothing useful to add. I run a GW-100. I have never measured the draft. I bought, but never installed, a dreft-inducing fan. The only way I measure exhaust temps is with a magnetic pipe thermometer. Especially on 8" pipe, the readings are relative at best.

I can tell you that this morning I was fussin' with a bed of coals with the draft closed. The water temp was about 175. When I closed the load door I heard a rumbling that I have never heard before. But I knew immediatly it was a chimney fire. I checked the pipe thermometer and it read about 500*. Previous to this I have never seen it over 400, and that was only with the flap open for a while and a load rippin. Not sure why the fire happened, but soon the flap opened and things settled down. The stove pipe never glowed that I noticed. When I got back home tonight the flap was closed with a partial load, and the magnetic thermometer read about 175*, which is about normal for a the damper closed.

All's well that ends well.

 

[byrddogwi]

Hi Byrddog,

This is my first post. My W-100 shows similar draft with the draft door closed as you get. I think that's normal - you don't have to have air flow to have a pressure differential.

When I first installed my Seton, the ash pan warped..I didn't have ashes or dirt in it at start up (my mistake). Anyway it leaked enough to make the temp climb steadily while it was cycled off. A peek in the door showed some glowing near the front of the boiler at the ash "hole" rather than in the back by the draft door. I sealed the bottom ash pan with silicone by putting globs on my fingertip and then reaching underneath it. It's a PITA reaching under there, you have to do some from the back and some from the front with a little stretching. Lesson learned: don't do it hot!! This leak caused a slow and GRADUAL temperature climb, rather than the usual 1-2 minute "spike" you see at the end of each cycle. The climb was only obvious under no-load conditions after I insulated my pipes.

When my boiler used to cycled off, the exhaust would cool to about 150F by the end of the closed cycle (about 3-7 minutes, depending on how hard it was running). With my new heat storage, my boiler doesn't cycle any more to speak of. It pretty much runs flat out (and much cleaner). When I shut it down now after a typical long, continuous burn, I now see about 200F to 250F on the exhaust for a while. So I know that the exhaust temp is realted to the boiler (refractory) temp as well as the amount of leakage. Bottom line is that mine leaks too, but I now realize that the idle exhaust temp is a function of the refractory temp as well as the rate of air leakage. I failed Anthony school...my leaks got worse when I put gasket material in. I'm going back for my Anthony GED once I finish getting all my new piping insulated. I, too, would be interested to hear what a "good" exhaust temp is on a tight Seton that has been running hard so I know what my goal should be. (I have a draft inducer, but I wired it so that it will only run with the draft door open.. so I can't do Anthony's vacuum leak check either without messing with the wiring a bit.)

mole

Thanks Mole. How old is your Seton? Mine is 3 years old but this is the 2nd season it has been in use.

I have no holes in the bottom of my firebox since I knocked out the old and "cemented" the floor with ceramic refractory as Fred instructed. I still have the ash pan under there with high temp RTV caulk from the original startup. I could try and gob some around the pan but I don't think that would help much. It is strange that after sealing up the beast it now seems to not shut down as well as it did before I sealed it, maybe it is just my imagination. I did not have the overtemp issue as much last year as I do this year. It should have ran overtemp more when it was not sealed up because it would get more air in when the draft was closed. Seems it should shut down better now that there are less leaks.

I was going to try to get storage going this year but I had to dig up my trench line and I put in some 1" thermopex which kind of broke the bank so I could not get storage going this year. If I can make it through this heating season I will try to add storage for next year.

Maybe Anthony or someone else who has had their Seton for a few years can chime in and let us know what temps and draft they are getting after the draft closes.

 

[trailhound68]

I got my hands on a nice Bacharach manometer last year thanks to a friend.
On 24' of 6" insulated SS with no inducer, similar to the picture in Fred's instruction binder that says 'this won't work',
I was measuring 0.12-0.17 wc when open. With a stack temp of 375-525 deg. And a high of 665 deg w/ really dry wood.
Closed I would measure 0.06-0.09 with a stack temp of 200-300 deg. Too much draft on a 6" stack w/ a reducer, 2 90's and a tee? Yup.
I know she leaks air and I swear I will seal it up on of these days. The door and the intake damper don't seem to leak much, just around the panels.
My unit does not have the ash drawer. I burn big hardwood, dry, green and in between. With a good bed of coals the beast loves big rounds.
This is the beginning of my second year. Last year I burned a lot of wood. She runs 24/7, until mid April.
This year so far I've taken one 4' section of stack off and that's it for mods. I hope to get my own manometer someday. For now she chugs along and doesn't make a big mess or get gummed up. I've said here before, I think mine is a little undersized and thats not a bad thing.

 

[antknee2]

Hi guys
It is very tricky to find and seal almost all the air leaks in a Seton , my biggest challenge was the draft damper , almost all components leaked like a sieve under a negative air conditions
For me It was worth the time and effort , I like push the boiler to it's upper limits for fast charging of the storage tanks , very dangerous , but the reaction time is fast when it shuts the damper on high limit . My seton also maintains a high draft reading and stack temp for a wile when damper is shut . I call it the Seton effect .
Anthony

 

[mole]

Thanks Mole. How old is your Seton? Mine is 3 years old but this is the 2nd season it has been in use.

I have no holes in the bottom of my firebox since I knocked out the old and "cemented" the floor with ceramic refractory as Fred instructed. I still have the ash pan under there with high temp RTV caulk from the original startup. I could try and gob some around the pan but I don't think that would help much. It is strange that after sealing up the beast it now seems to not shut down as well as it did before I sealed it, maybe it is just my imagination. I did not have the overtemp issue as much last year as I do this year. It should have ran overtemp more when it was not sealed up because it would get more air in when the draft was closed. Seems it should shut down better now that there are less leaks.

I was going to try to get storage going this year but I had to dig up my trench line and I put in some 1" thermopex which kind of broke the bank so I could not get storage going this year. If I can make it through this heating season I will try to add storage for next year.

Maybe Anthony or someone else who has had their Seton for a few years can chime in and let us know what temps and draft they are getting after the draft closes.

Byrddog,
This is my third season. It's been quite a learning curve.

 

[SteveJ]

Mole,

Can you post or describe your storage system?

 

[mole]

Steve,
I will try to post it sometime next week on a new thread. I need to get a chance to draw it out a little more neatly first. My storage and control system uses a lot of ideas borrowed from this site plus a few of my own.

 

[LeonMSPT]

Should think even with draft inducers and boilers, the old adage would still apply. "The chimney is the engine that makes the woodstove go."

Can have too much draft, which will overdrive the woodburning device and overheat it. Too little draft, too cold a fire, smoldering, and creosote build up.

The New Yorker I am installing calls for a barometric damper, to limit the draft.

Wood doesn't turn off and on, like oil, gas, or electric. When you reach peak temperature, the air supply closes, combustion fan shuts off... the temperature will still climb, and I wouldn't be surprised to see the overheat kick on each cycle of a boiler. It's working the way it's supposed to. Be happy.