Why design a stove that can't be shut down enought to prevent .....

[LarryP]

I have been using my new PE Neo 2.5 for a while and still have over firing problems. I have taken all the advice there is to prevent it. What's the use of a big stove that you can't fill, damp down and leave unattended with confidence? I have the best luck by partially covering the EBT opening.
I have a straight 15 foot run of old metalbestos chimney and have a real strong draft. I can usually hear the EBT shutter flapping around no matter what the lever setting is. Would a draft reducer, turn key type, in the stack help and why doesn't PE suggest this. Seems like they should have designed in an adjustment in the secondary air inlet(ETB). Thanks.

 

[begreen]

Most 24/7 burners here run the stove unattended with confidence. The risk of overfiring is quite low when the stove is run correctly. The EBT is flapping because at most stages of the burn the draft is changing. Strong winds could make it vary even more. I would not mess with it.

It's very unusual for a 15 ft chimney to have too strong draft. Tell us more about the overfires. What temperatures is the stove normally running at? What type of wood is being burned and what size splits?

 

[Grisu]

The unregulated secondary air is to reduce particulate emissions which are a health hazard and can lead to unsafe conditions due to creosote accumulation in the chimney. The EBT is designed to open up when the stove needs to pull more air to ensure complete combustion. AFAIK, it is normal during a burn to open during the peak.

How do define an overfire? What you have tried to avoid it? What is the diameter of the chimney?

 

[bobdog2o02]

What temps are you seeing during your "overfire"?

 

[brad wilton]

It could be normal burn just more intense because of full load .what size splits are you using and how dry

 

[LarryP]

The pipe is 6", when it seems to be over cranking (or not?) the Rutland magnetic thermo on the steel to under the trivet read about 640 and the old VT Group Chimney alert read 630, with the thermocouple about 30 " above the stove.
I burn 2 year old dry hard wood, 4x4 to 5x5 quarters and some unsplit 4,5,and 6" wood, 16 to 18 " long. Smaller stuff to restart fires or burn down excess coals. What gets me nervous is the occasional high temp of the 18 " of metalbestos
by the ceiling where it enters the pass thru box. I haven't put the therm on it by il will.

 

[begreen]

That's not overfiring. 650F is where most PE stoves like to cruise. With a good load our stove will peak around 700F and then settle down to 650F. 630F on the flue is a bit high for cruising, but not unusual as the fire reaches peak. On a fresh load I routinely spike around 750F on the flue probe in the pipe.

 

[bobdog2o02]

I think your having som vigorous secondaries but as long as your below 700 I'd say your good.

 

[LarryP]

I think your having som vigorous secondaries but as long as your below 700 I'd say your good.

 

[LarryP]

Hey, you guys are great. I guess I'm just not used to the unit yet, after using an old resolute since 1980.
Thanks for the reassurance. Think I might have liked a Princess better with its steady burn, but I'll get the hang of it.

 

[begreen]

I had the original Resolute back in the early 80's. It was a great stove. You are right, this stove will run differently, but hey, no bypass.

 

[DougA]

Just saw this thread and I wanted to add my thoughts. I had an overfire/very active fire a few nights ago. I posted on that but now have some more details. My stove collar was reading over 600 which is not an overfire, agreed. Last night, I installed the Auber digital flue thermometer that I had on my old VC unit to the new Equinox. I was concerned because the soapstone is so slow to respond to temps - that's actually a huge benefit.

So today I loaded up the stove 2/3 of the way with very dry medium sized splits on almost inactive coals. They caught on quickly and I turned the stove to the lowest setting possible pretty promptly. Yup, it got hot but no worry right? 600 is well within range - right? Well, my flue thermometer that is 14" above the stove hit over 1250 when I finally opened the door to allow max air in so it would cool down a bit. The flue thermometer cooled instantly but the fire went nuts. - (nuts is the Cdn word for 'holy sh*t') I threw in a very damp split and it ate it up like nothing. This fire was not nearly as active as the one I had a few days ago. I can only speculate what the flue temps might have been but I was using smaller splits on a full load so I'm guessing 1500+ just by the smell. THAT IS IN THE DANGER ZONE in my books. No, the smoke detector did not go off today (was on for 15 min the other night) and I did check all 5 detectors we have to ensure the batteries were all good this afternoon.

I understand the EPA and design parameters but being able to close down the air more is a safety issue which to my mind, trumps air issues. I will be calling Ray at Hearthstone when I get back from holidays to seek advice on how to make these changes. If they are unable to make suggestions, I'll find a way myself. My summary FWIW is that 20% wood burns fine, over that, burns OK, dryer than that gets risky.
Yes, I can add a flue damper and toyed with that thought during installation. The reality is that in one month of using this stove, there are times when it's damp outside that I have had the air control mostly open. The control needs more range without a doubt.

For those interested in specs., my 8" stove pipe is double wall for about 12', then 8' of SS chimney above that. It includes 2 - 30 deg elbows. 20' is not a lot in my books. Wood is assorted hardwood but mostly dead elm. This is my last post for a week as I will not be able to access the forum easily while sunning in the Caribbean.
Don't hang me in my absence please, I would rather be here to see that myself. .

 

[begreen]

LarryP, the Resolute's air supply is thermostatically regulated. So are BK stoves'. That's what you are more used to. The Neo is going to be more of a pulse and glide sort of heat.

 

[highanddryinco]

Yeah, I gotta agree with the guys in the know here...you're fine. On my PE Super, if I'm anywhere even close to a full load, I can't keep it below 700 stovetop. A 750 peak with a fallback to between 650 and 700 is a regular occurrence. Came home from work last night, smelled that new stove smell (from my year old stove) as I walk in the door, hear the pipes clicking away, wife and daughter sitting on the couch watching TV rather sheepishly. I remove my boots and walk in to see the iron and stainless stove innards displaying a glowing orange hue. Stovetop is tickling 800. I look back at the girls and daughter says, "You always tell me not to let it go below 350 and Mom barely had it running 250. I closed it all the way down at 400." I had to admire my teenager for actually listening and repeating something I told her in the past and also her attempt at throwing her mother under the bus.
I am truly the luckiest man in the world. I just don't think I want to know where that thermo was a half an hour earlier.
We all got a reminder of how these PE's like to climb. Two hours later, cruising along at a comfortable 600 and change.

 

[Hogwildz]

Keep in mind the size splits you load, and how much air space is between them.
The PE's like large & medium splits, and will eat a load of small splits like Bruce Jenner on a Wheaties box.
For that fact most stoves will go crazy loaded full with small splits, with exception of maybe cat stoves, I really can't speak for them given my limited knowledge of those stoves.

 

[SKIN052]

Sounds like your running it great. 650 is fine, often happens for me. I would leave the EBT alone. The main firebox air is easily modified to restrict air, I would do that rather than mess with the EBT.

 

[bobdog2o02]

They caught on quickly and I turned the stove to the lowest setting possible pretty promptly. Yup, it got hot but no worry right? 600 is well within range - right? Well, my flue thermometer that is 14" above the stove hit over 1250 when I finally opened the door to allow max air in so it would cool down a bit

If you were reading 1250 from a probe inside the flue you are well within the norm. Readings from magnetic type thermometers read the temp of the outside of the pipe, its been said here often that the temp inside the pipe can be double that. Everything is fine, you just have a different type of stove now.

I run a BK princess now but my old US 2500 would regularly find its way p to 750 pipe for short periods at the beginning of a burn. Try some bigger splits that wont gas off as fast, it might make you feel a bit for at ease.

 

[DougA]

If you were reading 1250 from a probe inside the flue you are well within the norm.

Sorry, can't agree with that.
Specs from ICC site are here:
Allowable Flue Gas Temperatures
Max Continuous 650°C (1200°F)
Brief Forced Firing 925°C (1700°F)
Tested To 1150°C (2100°F)

If I had not acted to reduce the temp, they would have gone to 1500 and been above the 1200 limit for much more than 'brief'.

I expect that many members here who do not have a digital flue probe would be astounded how high their temps get to. Yes, the chimney can probably take the heat but the risk is not worth it.

 

[begreen]

Yes, I don't like seeing my flue pipe getting up those temps. An occasional spike to 1000F is likely to be ok, but one should not be seeing continuous flue probe temps over 1000F. Also, a while back I seem to recall Condar saying that frequent forays to 1000F would reduce the accuracy of their thermometer.