Secondaries going, single wall stovepipe temp ?

[Mark Richards]

I think I've got this EPA stove burning thing down now after a few months of use but still have this nagging question. When the stove has been burning all day for example and I load new wood in do I still need to get the stovepipe temps back up into the optimum burn range of my magnetic thermometer to avoid creosote problems even though the secondaries are really firing nicely. Too get my stovepipe back up to the 300 degree range I would have to burn up alot of the new load of fuel sending alot of BTU's up the chimney. If the secondaries are firing good do you need the stovepipe temps so high? Isnt the secondary combustion taking care of the creosote procucing elements?

Thanks

 

[Nick Mystic]

Take a look at the top of your chimney during the time in question. If you see smoke exiting the chimney, then you have smoke and the makings of creosote passing through your liner. If you only see the shimmering heat, then you're good to go. Secondaries can be firing off nicely, but you can still have smoke coming out your stack under the right conditions (too much smoke for the secondaries to burn off). Other times the secondaries can be sitting idle and you have a nice clean burn leaving the stove (for example, near the end of a burn).

 

[oldspark]

This could be an interesting thread.
The first part of the fire is the dirtiest part of the burn so what Nick said should apply.
My flue temps seem to be higher then most on here, I have lower flue temps with the old stove.

 

[Sprinter]

Some general thoughts.

If you still have a nice hot bed of coals to work with, it won't take long for the fire to take off and flue temps to rise. In that case, I wouldn't worry about it. If, as you said in the post, the secondaries are firing nicely, this would likely be the case.

If you're trying to start basically a new fire with a very cool stove, I would (and do) turn the air up and get the fire going well before turning it down just like a new fire.

Those magnetic flue thermometers have some time delay, so the internal flue temps are probably getting higher than you think at first.

 

[oldspark]

I guess we need more of a time frame for how long this takes, no delay on my flue temp thermometer, it goes up right away and I double check it with a IR testor.

 

[Sprinter]

no delay on my flue temp thermometer

Yeah, it's probably a minor issue anyway.

 

[Mark Richards]

Some general thoughts.

If you still have a nice hot bed of coals to work with, it won't take long for the fire to take off and flue temps to rise. In that case, I wouldn't worry about it. If, as you said in the post, the secondaries are firing nicely, this would likely be the case.

If you're trying to start basically a new fire with a very cool stove, I would (and do) turn the air up and get the fire going well before turning it down just like a new fire.

Those magnetic flue thermometers have some time delay, so the internal flue temps are probably getting higher than you think at first.

Yep this relates to when you have a very nice hot bed of coals and your firebox temps are still very high, not a cold start. With my stove once I reach the point where I can start closing my control, my flue temps always drop and then spend the rest of the burn time below what the magnetic thermometer says is the optimal burn temp (Rutland thermometer). When I reload on hot coals I usually just let it burn on full air until I see the secondaries kicked in good and strong (Doesn't take long with a good coal bed) then close down the air in stages. My stack temps stay below the optimal burn indication, secondaries stay lit, I see no visable smoke from chimney, but my thermometer reading stays below 325 degrees. Still learning.

 

[oldspark]

Yep this relates to when you have a very nice hot bed of coals and your firebox temps are still very high, not a cold start. With my stove once I reach the point where I can start closing my control, my flue temps always drop and then spend the rest of the burn time below what the magnetic thermometer says is the optimal burn temp (Rutland thermometer). When I reload on hot coals I usually just let it burn on full air until I see the secondaries kicked in good and strong (Doesn't take long with a good coal bed) then close down the air in stages. My stack temps stay below the optimal burn indication, secondaries stay lit, I see no visable smoke from chimney, but my thermometer reading stays below 325 degrees. Still learning.

Thats kinda what I was saying in my post, my flue temps are way higher then most on here and I just dont get it, when I first bough the stove I though something was wrong with it and now posts like yours make me think that again.
Not going to hyjack this thread so I might start a thread about flue temps again.

 

[Sprinter]

With my stove once I reach the point where I can start closing my control, my flue temps always drop and then spend the rest of the burn time below what the magnetic thermometer says is the optimal burn temp (Rutland thermometer).

My stack temps stay below the optimal burn indication, secondaries stay lit, I see no visable smoke from chimney, but my thermometer reading stays below 325 degrees.

I assume you have single wall pipe with that thermometer. Remember that the thermometer is only reading the surface temp of the pipe. The internal temps, which is what is normally referred to, will be roughly twice that. So 650F internal is about right for a mature burn.

What does the Rutland say is the optimal burn temp? And can you confirm the readings with an IR thermometer or something?

 

[oldspark]

Hes talking 300 degrees on the magnetic unit so hes right with that, surface temps are used for single wall for the most part.

 

[Sprinter]

my flue temps always drop and then spend the rest of the burn time below what the magnetic thermometer says is the optimal burn temp (Rutland thermometer).

Is it this thermometer? http://www.amazon.com/Rutland-701-Stove-Thermometer-Each/dp/B000627RGM

I think that thermometer is made more for stove tops. The temp readings are probably fine, but the zone guides are too high for flues, IMO. Compare that one with this Condar made specifically for single wall pipe
(broken link removed to http://www.condar.com/stovepipe_meters.html)

 

[YkDave]

With a fresh fire, or after a refuel I'll run mine around ~350, once it's warmed up or the new load charred I almost always cut the air off as far as it will go (or else I will have a heat stroke!)

Then the majority of the secondary burn will leave the pipe around 250-275, dropping off finally when it's getting down to embers

Nothing more than a little grey ash in the pipe after 3 months, so I'm not too worried about running it a bit below "optimal" temps with the wood I've got

 

[oldspark]

With a fresh fire, or after a refuel I'll run mine around ~350, once it's warmed up or the new load charred I almost always cut the air off as far as it will go (or else I will have a heat stroke!)

Then the majority of the secondary burn will leave the pipe around 250-275, dropping off finally when it's getting down to embers

Nothing more than a little grey ash in the pipe after 3 months, so I'm not too worried about running it a bit below "optimal" temps with the wood I've got

If I ran my stove like that I would have a smoldering fire, and that's with two different chimneys, still think for some reason my stove does not work correctly.
You are talking surface temp on single wall correct?

 

[Sprinter]

With a fresh fire, or after a refuel I'll run mine around ~350, once it's warmed up or the new load charred I almost always cut the air off as far as it will go (or else I will have a heat stroke!)

Then the majority of the secondary burn will leave the pipe around 250-275, dropping off finally when it's getting down to embers

Nothing more than a little grey ash in the pipe after 3 months, so I'm not too worried about running it a bit below "optimal" temps with the wood I've got

Assuming those are surface temps on single wall, in F not C, those temps sound normal. Or even if it's double wall and Centigrade internals. 350F surface would be about 700 internal which is about right for startup and running. That's about what I run at except I have double wall and a probe thermometer and read internal temps.

 

[YkDave]

Yes, surface temps on single wall pipe

 

[Sprinter]

Mark, is your question answered? I think the bottom line is that if your thermometer reads at or above 250F on the surface, you're fine. If it starts out below that, it shouldn't take long enough to get it back up to be concerned about one way or the other.

 

[oldspark]

Do not see his answer about the chimney smoking when he reloads and has those flue temps, did I miss it.

 

[esox]

I'm in the learning stage also with my summit and have been messing around with it when I'm home on the weekends to see how it reacts differently to air settings. I've found that a reload on a good bed of coals with the air open for about 20 minutes gets the fire going nicely and I don't have a gauge on it but its probably around 500 or so. After the 20 minutes or so I set the air to half way and at this point is when the secondaries are working. When I reload the stove in the beginning I'm getting smoke out the chimney and it settles down when I take off the air. Makes sense. After another 20 minutes or so I set the air just a bit off the low setting and I got zero smoke outside. I've been burning it about 6 weeks now and my chimney cap shows no sign of creosote.With my old Fisher I'd be up there by this point cleaning off all the crap on the cap and sweeping the liner. I think I have it figured out pretty well. I'm getting a good 10 hours of real heat with a large amount of usable coals. In fact due to my work schedule I'm wasting a lot of good coals to make room in the firebox for a full load. If I were here all the time it wouldn't be an issue. Just set the stove on high to burn the coals down and make use of them but I cant do that. Still 99% better than what I had before.

 

[YkDave]

Mine does smoke a bit after a reload too, it doesn't clear up for at least an hour with a full load that's been charred for ~15min and the secondaries burning good with the air cut

If their was buildup in the pipe, or the smoke was bothering neighbors I would be worried, but it burns clean as a whistle and the neighbors fires smoke worse than mine, so all is good

 

[oldspark]

Mine does smoke a bit after a reload too, it doesn't clear up for at least an hour with a full load that's been charred for ~15min and the secondaries burning good with the air cut

Yes I agree sounds like it is not an issue, I have high flue temps but mine hardly ever smokes for any length of time, no way would mine smoke for an hour.

 

[ddahlgren]

Smoking for an hour might make me question how dry the wood really is. Right now the probe says 375F the Rutland on the single wall surface reads 185 and the stove top 500 and I am not concerned at all.

 

[oldspark]

Smoking for an hour might make me question how dry the wood really is. Right now the probe says 375F the Rutland on the single wall surface reads 185 and the stove top 500 and I am not concerned at all.

I agree, it really should not smoke for an hour.
Your temps on your flue compared to your stove top are impressive.

 

[Mark Richards]

Is it this thermometer? http://www.amazon.com/Rutland-701-Stove-Thermometer-Each/dp/B000627RGM

I think that thermometer is made more for stove tops. The temp readings are probably fine, but the zone guides are too high for flues, IMO. Compare that one with this Condar made specifically for single wall pipe
(broken link removed to http://www.condar.com/stovepipe_meters.html)

Yep thats the one. It said on the package that it was made for the stovepipe @ 18" above stove. From reading post here and other places I see that those things can be inaccurate and really need to be taken with a grain of salt. I have come to use it more on the top of stove now as a guide to firebox temps. I am relying more and more with each fire made to use my eyes as the guide to when to start shutting things down and worrying less about the thermometer. If I'm getting good secondaries and no smoke out of the chimney the temps must be right and i must be operating the stove correctly I'm guessing. I have just received my chimney cleaning stuff today and hope to use it this weekend to see what kind of shape my chimney is in. I have a feeling that I'll have a bit of creosote buildup because when I was just learning with this stove I had quite a few smokey fires before realizing I needed to let the stove rip before shutting it down.

 

[Sprinter]

Yep thats the one. It said on the package that it was made for the stovepipe @ 18" above stove.

It seems to be marketed for use on both surfaces, which is fine, but I just think that the "creosote" - "burn zone" line is a little conservative at 275 surface temp. It may make you sometimes think that you're making creosote at 250 which is about 500 internal and a normal operating area.

Let us know how your flue looks. I'm guessing it will be fine.

 

[Mark Richards]

whoops, its actually from a company called Meccos but looks almost identical to the Rutland.

It seems to be marketed for use on both surfaces, which is fine, but I just think that the "creosote" - "burn zone" line is a little conservative at 275 surface temp. It may make you sometimes think that you're making creosote at 250 which is about 500 internal and a normal operating area.

Let us know how your flue looks. I'm guessing it will be fine.