Econoburn EWB 300 short burn time and high stack temperature

[mark cline]

I have been running my 300 for about 2 weeks and always had short burn times and stack temperatures up to 580F. I load the boiler up to the bottom of the loading door on an initial load and on a reload . So we are talking about 25 mixed hardwood splits both times . I recently installed a PID controller to monitor temps. After an hr of lighting , the temps climb up to 450 , then suddenly climb to 550 plus. The spin air controls under the fan cover are set at 2 1/2 turns open, the draft wheel on the fan is set at 2 1/2” at the widest point on the 2 pie shaped openings. Burn time about 2 1/2 hrs. On a reload, same amount of wood , the temperature will climb to 580 at about the 1 hr mark and slowly decrease over the next 2 hrs. I can raise the 1500 gallons of storage from 120 to 180 in this 5 1/2 hr time frame . Am I missing something? Flue pipe is 16’ of double wall stainless 8” . The boiler is essentially new with Econoburn, doing a total rehab which included a total replacement of the back of the boiler and heat exchanger. Airlina has been coaching me along on the startup , great thanks to him, but I’m at a loss as to what can correct this problem.

 

[brenndatomu]

Sounds to me like you need less air going through the boiler...can you close that fan down more? What's your chimney draft?

 

[salecker]

Why are you loading 1/2 loads?
Try closing off your openings a bit.
I know another Econoburn user has had luck in throttling down the air going into the boiler.He has made some additional regulating flaps for slowing the flow.I believe he is on the right track.
I have thought for a while mine was getting to much air as well.
I havn't messed with mine yet because life hasn't given me time to make the boiler a priority.
My system works well,11 years and i know that if we get a stretch of -40 weather i don't have to worry.I know how much i will burn and when i have to start the fire.
One day maybe next fall i will have some time to tweak it.And insulate my piping in the boiler building.
An easy tweak would be to be able to slow the fan down with a adjustable dial.Not sure if the fan motor would be happy doing that.
Thomas

 

[cumminstinkerer]

I am the Other user @salecker mentioned, I was having the same issues as you are only with my 100. I tried slowing the fan down as an experiment, but that didn't work well as it slows the secondary air down as well, my solution has been to remove the fan mounting plate and created plates the are adjustable like the secondary air screws that regulate the primary air. It was fairly easy and the only thing you are changing physically with the boiler is adding to holes in that fan plate, I welded nuts to the back side but you also thread the plate. It has greatly improved my burn times, from 1.5 hours out to 2.5-3 and the flue temps are now only briefly spiking above 500F for maybe 15 minutes at peak burn. I need to add longer adjusting screws so I don't have to remove the fan cover, design oversight ( I was in a huge hurry that night). I also need to replace my nozzle as it is badly worn, I think caused by the over air causing ash/coals to fly through eroding the nozzle. Once the nozzle is replaced I will fine tune some more but the results are very promising. @airlina also has a 100 and we have talked a lot and he has been a great help but for some reason his behaves totally different than mine. I would be glad to help, I think I have some pictures of the flaps I can send you, shoot me a PM with your number.
Jason

 

[cumminstinkerer]

@mark cline also visually inspect the bypass flap, mine was not sealing properly, the arm it hooks to had gotten bent, I bought the boiler 3rd hand but the second owner never used it, I think it was treated very poorly. I really do find it interesting that two identical boilers can behave so differently, I cant explain it, mine and Airlina's are the same thing but for some unknown reason mine either flows too much primary air or wants less, makes no sense but I can promise the mods to mine made a different boiler out of it. @goosegunner had similar issues with a 150 and eventually got rid of it because of that, now others I've talked with have had perfect plug and play if you will luck. Good luck and feel free to get in touch.

 

[mark cline]

Loading half loads as you call it , comes down to getting familiar with the boiler and 2 loads that size bring my storage up to 180F also a little leary with the high temperatures.

 

[salecker]

Ok i see
I usually don't have time to mess with 1/2 loads except at the end of loading my storage.
First fire of the day gets assembled in the fire box with the initial burn with bypass open,the upper chamber gets filled to the top.I assemble the wood in a way that seems to work well,have never had a fire not catch and burn. With storage i have had power go out after a full load and no issues.
What are you using to measure your stack temperature? I just have a cheepo mag that i found.

 

[mark cline]

Going to take off the front panel that the fan is attached to, later today. This morning when the fire was out, I turned the fan on and there was not much air coming out of the rear nozzle. Really not much coming out of the front either.
My thinking is this.... the blower provides the majority of the pressure through the nozzle and the secondary provides heated air for ignition?????? Always had the fire light , but have a hard time getting the secondary to light unless the flue temp and the firebox is hot like 375plus.
PID temperature controller was just installed , I always suspected high flue temperatures , needed a way to monitor and provide end of burn shut down.

 

[cumminstinkerer]

@mark cline I did verify my PID with two other BBQ probes and it is within a couple degrees, I wondered the same thing, I forgot to mention earlier, make sure the anti backdraft flap/s aren't stuck closed, have had that too, I really wonder if you don't have the drill burrs in the secondary tubes or a chunk of s**t in one or both of them

 

[SSweet9c1]

OK, I'm on my 3rd full season heating with my 2018 Econoburn 170-200, I have some newby type questions, what is PID short for?
Also are there instructions on adjusting/ monitoring airflow? I've never touched the fan/fan cover etc... But I am seeing fairly high stack temps on the digital readout, Also burn time is less than 4 hours which drives me NUTS, build a fire at lunch and it's out by the time I get home from work. 1000 gallon thermal storage tanks in wood boiler room in wood shed, about 100' from house, House is around 3500 sf.
thanks
Jon

 

[mark cline]

Hey Jon , if you read any threads that have to do with Econoburn within the last 10 years or so , you will find a lot of information that we have been through as we learned how our boilers work. There are many owners of Econoburn boilers from my 300 down to many with the 100. I see your in the finger lakes , so Airlina and I are within about 75 miles of you . Weather, wood species etc will be close to what you experience.
A PID controller is essentially and on off switch controlled by temperature. A proportional–integral–derivative controller is a control loop mechanism employing feedback that is widely used in industrial control systems and a variety of other applications requiring continuously modulated control.
On my boiler, I have 2 PID controllers , one will shut off the blower when the fire cools to a set point, the other will turn off all power to the boiler when the temperature falls below a set point. Essentially the boiler will shut it self down at the end of the burn.
What you have experienced with your boiler, we all have learned over the years how to control the stack temperatures with different methods. I’ll run you through what I have experienced and did to correct the high stack temperatures. First off , I have a barometric damper on the flue which helps to correct an over draft problem. My flue is 8” and 24’ high , so my damper is set way higher than recommended. Next is the blower inlet control, it’s a pie shaped louver that restricts the air flow into the boiler. The blowers on the Econoburn boilers allow way too much airflow, which will drive the flue temperatures up and shorten the burn time. Cumminstinker and I have made primary air controls for restricting the air into the boiler (see the thread about this) , this may or may not be needed if you can restrict the blower inlet. The secondary air is also reduced significantly. Read the threads and there will be many here that will be glad to help.

 

[maple1]

OK, I'm on my 3rd full season heating with my 2018 Econoburn 170-200, I have some newby type questions, what is PID short for?
Also are there instructions on adjusting/ monitoring airflow? I've never touched the fan/fan cover etc... But I am seeing fairly high stack temps on the digital readout, Also burn time is less than 4 hours which drives me NUTS, build a fire at lunch and it's out by the time I get home from work. 1000 gallon thermal storage tanks in wood boiler room in wood shed, about 100' from house, House is around 3500 sf.
thanks
Jon

4 hour burn time is about what it is supposed to be. Burn wide open until the fuel is gone while storing heat for later. Repeat. Keeping it properly clean will make sure you are capturing the heat.

 

[salecker]

Yup 4 hours is what a full load would last for me as well.
If you have storage why is you fire controlling you?
I get home around 5 ish and start my fire which then burns till 10 ish or later depending on outside temps.
When it's -40 then i have to start burning at 2ish.

 

[SSweet9c1]

The problem I see with the thermal storage, and I haven't figured out how to program it out (if possible) so the fan shuts off when the fire goes out, is that the stack temp from the hot water will keep the boiler trying to start after all the wood is burned up in the middle of the night, so it kicks the fans on for 30 minutes, the fire never lights, so it kicks off, then tries again to relight, but if it's the middle of the night, obviously I haven't refilled the boiler so it's just blowing air through the boiler.. (the primary pump stays running as long as the storage tank has reached "target temp"). So when I get up the next morning half the time the fan is still trying to get the boiler running..

it was 4*f last night, and when I went to bed my 1000 gallon tank was at 180*, this morning it was down to 120* Most of the winter the temps here are in the mid teens-mid 20's and it's not such a load on the boiler. But it takes 15-20 minutes to start a fire from scratch, and if I have to do it 3X a day when the temps are in the single digits, its a pain.

My boiler is from 2018, and Just in the last couple weeks I've started letting the last load of the night get about halfway burned down, (say load it up at 8pm,) then at bed time (10 ish) I go out and shut off the blower, mine has a manual toggle switch for just the fan.. This keeps the circ pumps running etc... If I do this I lose the last 4 hours of burn time, but at 6am when I let the dog out, I can just kick the fan back on and I have a bed of hot coals, and have the boiler going full tilt in 5 minutes... As opposed to starting a fire from scratch and having it take 30 minutes to get it up to speed... .
Is there anything wrong with doing it this way?
Thanks
Jon

 

[mark cline]

Jon , what is your type of heating in the house ? Forced air , baseboard radiators, radiant floor, wall radiators? If you can lower your useable temperature, your storage will last longer . I have radiant floor heat that I run at 100-110F my 1500 gallon storage is about 180-190 at night at 160 in the morning and about 140F when I fire up the boiler about noon , 1 o’clock.
My boiler is a 2011, so my controls are different than yours. I have a PID controller that turns the blower off at 160F stack temperature and another PID controller that turns off all power to the boiler when the stack temperature hits 150F, which turns off the pump . If for what ever reason the boiler temperature comes up to 150F , from a large pile of burning coals , the power is restored and the pump comes on . When I fire the boiler the next day , power is not restored until the stack temperature comes up to 150F , then I have to reset my high limit to 205F . Hope this helps , you’ll get it dialed in .
Loading your boiler in the evening then shutting off the blower later could cause creosote build up if the wood is not burned completely to coals. I get your thinking that you throw in the wood and it takes off in minutes, makes it easy .

 

[salecker]

It's your timing that is the biggest issue
Yesterday it was -35C in the morning,it cooled down from -12 the day before.
So yesterday i started my fire at 3:30pm because of the cold,reloaded at 6 PM next reload was 8:30 PM which was the last load and i went to shut off the boiler at 12:30AM after my movie was done.
My last load was all gone with a baseball sized ember left.My indicator light was off telling me my stack temp was down,If i wasn't watching a movie i probably would have shut down the boiler around midnight.
-41C here as i type. My storage will take me to around 3 PM again today,if i know i am in for a cold night i will make sure i get the storage to max which is 185 ish
Unless i forget and don't re-stoke i only start one fire a day.
i have 1000 gal storage

 

[Woodman1]

It's your timing that is the biggest issue
Yesterday it was -35C in the morning,it cooled down from -12 the day before.
So yesterday i started my fire at 3:30pm because of the cold,reloaded at 6 PM next reload was 8:30 PM which was the last load and i went to shut off the boiler at 12:30AM after my movie was done.
My last load was all gone with a baseball sized ember left.My indicator light was off telling me my stack temp was down,If i wasn't watching a movie i probably would have shut down the boiler around midnight.
-41C here as i type. My storage will take me to around 3 PM again today,if i know i am in for a cold night i will make sure i get the storage to max which is 185 ish
Unless i forget and don't re-stoke i only start one fire a day.
i have 1000 gal storage

I think you must have a really tight house. You just described my schedule to a t for anything down to 0 degrees f. The few times we have gotten down to -20f it pretty much sucks the heat from the house!

 

[salecker]

I built my house as good as i could.
R120 in most of the roof,R 90ish in the rest
Quad pane windows
Log walls. There are a few different thoughts on log walls.The guy that did my log work does awesome work.I have not used any chinking after the walls were built.
Basement needs upgrading in the future,R20 walls.Things were tight when i built the basement,we lived in the basement for 15 years,12 before we put the log house on the basement.

 

[SSweet9c1]

Sorry for slow response.. My free time is mostly on weekends. :D

Our whole house is baseboard hot water... House was built in 1837.... I've been toying with the idea of putting radiant floor under the living room/kitchen.. That's really the only area that the baseboard can't keep up with as the storage tank cools... It's really a first world problem, go to bed it's 71F, wake up and the kitchen is only 66*F.. When it's single digit F, it takes the better part of the morning for kitchen to heat up as the storage tank has a hell of a time gaining temp while playing catch-up on the house... We re-sided the house when we bought it and replaced the tattered and missing fiberglass between the 4" studs with rigid foam (R of 7/inch), then put OSB, house wrap and Hardi siding... two of the walls were 6" studs so we put 6" foam in them... And I put R38 fiberglass in the attic, then put another ~4-6" blown in fiberglass over top to fill any gaps..

I wish we'd done more.. In our previous house (also 1800's house) we re-sided it and put 4" fiberglass between studs, then put 1" foam outside of studs, then OSB, wrap, siding etc.. That I feel did a much better job insulating... Also that house was ~2000 SF, and our current house is over 3500SF lol

If I were to put radiant floor in kitchen/living room, should I put it on a separate loop? Or just plumb into the baseboard on the return?
Thanks
Jon

 

[mark cline]

Your radiant floor would be about 110 -115 F and your baseboard is probably around 130 +. Never thought about it going on the end of your baseboard, I guess it would work. You would have figure out your pex length, you don’t want to go over 300’ for the baseboard and radiant floor .
Your insulation sounds like you put some thought into it , how good are your windows and your foundation, a house that old most likely has a stone foundation.

 

[SSweet9c1]

Stone foundation, pointed up two summers ago down to about 12" below grade, Most of the basement has 2" rigid on the inside of the foundation, looks like hell, and I'm not sure how much I gain from it... Would be worth 4X as much if it were on the outside of the foundation lol... plenty of cool air coming in from the crawl space portion.

Windows were all new when we re did the siding, triple pane in the upstairs, and smaller downstairs windows, the larger downstairs windows are double pane... They were supposed to be high quality, but I am not impressed.... but definitely better than the originals.

 

[SSweet9c1]

I could put the radiant on a separate zone, but our taco zone controller only has 4 zones, all being utilized.. Though we re did the manifolds with new circulation pumps when we put the wood boiler in, the old setup was a nightmare of ancient crummy wiring, 4 different pumps from different centuries lol. When we did this we plumbed in an extra set of valves for a 5th zone, thinking either DHW or radiant etc...

I'm no HVAC guy, but I think I'd have to get a 6 zone taco controller?

 

[mark cline]

Or add on another 2-3 valve controller. I put in a 6 zone Taco controller just to have the extra room if needed, it gives 1 zone not used . May use it for a radiant floor in the loft master bathroom .
Sounds like you’re doing all you can retrofitting , I guess if you feel cold air coming in, stop it best you can . I’m finishing my hand crafted log home , slowly , due Covid and supply chain issues, but I’ve found the foam gap filler to be my best defense. I’ll identify about a dozen gaps to fill and then use a full can , a half full can is useless after a few weeks of sitting on the shelf.

 

[SSweet9c1]

Dumb question, and this is probably covered in another thread, but how many face cords do you folks burn through in a winter? I know we all have different boilers, different climates, different houses and different wood. lol but I make sure there are 35 face cords in the shed before winter hits.. The first 5 are in a separate area of the shed and are stacked the previous winter, and then are the first to get burned the following season. My main storage area I can only load back to front and burn front to back (conveniently) so I like to have 5 FC stacked on the opposite wall of the wood shed nice and dry to buy me drying time for that front row in my main area...

 

[mark cline]

I started burning my boiler this year on December 6 when I got back from my Texas hunting trip . To this day, I have burned about 3.5 full cord or 9.33 face cord for 58 days of burning .
Was crunching some numbers , 35 cord if stacked up to 6’ tall , you would need a wood shed about 32x32. I throw my wood into the back of my barn ( not stacked ) up to the boiler shed approximately 12 wide x 8’ tall(average) x 32’ long this will yield about 16 full cord or 48 face cord. This would be my first full year burning the 300 boiler , so I would think I would use about 20 face cord or 6.33 full cord , burning up to April 1st .