Englander 28-4000 low flue temps

[Bigeejakes]

Hello! I'm a long-time lurker and first time poster... I love this forum - it's a wealth of knowledge, and I've appreciated everything about it!

I have an odd situation - my new, Englander 28-4000 add-on furnace is installed to a new 6" 23ft stainless, insulated chimney liner on an existing outdoor block chimney. Which enters the house through the old stone foundation, and into double-walled stove pipe which is connected to the new furnace.

Everything has been working great! The furnace has been keeping the house in the mid-70's during our 30 degree weather here in michigan, and we'll see what it does when we get some real cold... but theres been one thing bugging me about how it's running.

Even though the stove is running exactly as I would expect it to, the front panel reading around 450*F, good secondaries with the air about 1/3 open, and long burns around 6-8 Hours depending on how full I stuff it. I've checked the draft with a dwyer mark II and it's reading -.06, and Ive seen up to -.10" (The manual says don't have it over -.06, but shut all the way down it still snuffs out the fire).

Except my flue is reading temperatures of 250-300, which is much cooler than I'd like... I'm assuming that it's going to need cleaning often at that temp? (I've had it running about 3-4 days and haven't checked for build up yet).

At this point it's my only concern about the setup - very happy with everything else... is it something that you would tinker with or just call it good and figure out how often I need to clean it?.

 

[Bigeejakes]

Also - the flue temp is taken with a condar probe thermometer (since it's double walled). I've also used the same thermometer on my Hearthstone Manchester stove (Upstairs - which is a secondary heat source and for enjoyment)... and I get much different temps... like 600*F in the flue while the stove is cruising around 450-500).

 

[maple1]

I would just keep an eye on chimney and watch for buildup before doing anything else.

 

[3fordasho]

Also - the flue temp is taken with a condar probe thermometer (since it's double walled). I've also used the same thermometer on my Hearthstone Manchester stove (Upstairs - which is a secondary heat source and for enjoyment)... and I get much different temps... like 600*F in the flue while the stove is cruising around 450-500).

I had that thermometer and it read low, I had it in a telescoping section of double wall connector pipe and discovered that in the sliding section there can be 4 layers of sheet metal depending where you install it. The Condar only will work in a 2 layer section. I also prefer a temp probe where the actual measuring coil is in the probe, not on the back of the dial - I find them more accurate but must be recalibrated if you over-temp them.

 

[JRHAWK9]

yeah, chances are the probe is not accurate OR it happens to be inserted into a section of pipe or at a depth where it's not reading the actual max temp of flue gasses in that area.

I played around with the location (top vs bottom) of my temp probe and were it's inserted as well as the depth of insertion makes a difference. Just pulling it out an inch from full insertion made the temp drop ~50°. On the good EPA furnaces, flue temps on the low side, around 300° is normal though. When on pilot for long periods of time when the computer is going on/off pilot, I can see my flue temps drop to high 290's. This is with the probe placed within a foot of the collar, on top of the pipe and inserted to about the middle of the pipe.

 

[Bigeejakes]

yeah, chances are the probe is not accurate OR it happens to be inserted into a section of pipe or at a depth where it's not reading the actual max temp of flue gasses in that area.

I played around with the location (top vs bottom) of my temp probe and were it's inserted as well as the depth of insertion makes a difference. Just pulling it out an inch from full insertion made the temp drop ~50°. On the good EPA furnaces, flue temps on the low side, around 300° is normal though. When on pilot for long periods of time when the computer is going on/off pilot, I can see my flue temps drop to high 290's. This is with the probe placed within a foot of the collar, on top of the pipe and inserted to about the middle of the pipe.

That's good to hear that other epa stoves have temps around the same. I'm sure it's a good thing as it means the heat is going into the stove and room instead of up the flue? This helps to not sweat it and i'll just keep an eye on the chimney

 

[JRHAWK9]

That's good to hear that other epa stoves have temps around the same. I'm sure it's a good thing as it means the heat is going into the stove and room instead of up the flue? This helps to not sweat it and i'll just keep an eye on the chimney

It's a good thing as long as you are burning clean.

 

[brenndatomu]

I've checked the draft with a dwyer mark II and it's reading -.06, and Ive seen up to -.10" (The manual says don't have it over -.06, but shut all the way down it still snuffs out the fire).

I'm not following...how are you adjusting the draft? With the stove damper?
You need to control chimney draft with a manual pipe damper, or better yet a barometric damper.
Much easier to control your burn when you have a steady chimney draft!
If you are just trying to control with the stove damper now, everything you do has a snowball effect to it...a bit too much turns into way too much (fire dies) and not quite enough turn into -0.10"...which is most certainly too high!

 

[Bigeejakes]

Yes, right now I'm just using the air controls. I might as well install a pipe damper first seeing how cheap they are thanks!

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[Bigeejakes]

Yes, right now I'm just using the air controls. I might as well install a pipe damper first seeing how cheap and easy to add they are... I could see a baro in m y future thanks! I'll let you guys know what I find out.

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[Bigeejakes]

Ok, flue damper installed and first fire with it is running now. It did help to slow down the flames and get more of that lazy look. Stove temps seem good, stove pipe was slightly higher with the damper closed a bit and stove cruising.

I was curious as to the draft, as it still read around .1 when the chimney was up to temp and damper closed down.... Which I guess makes sense, you're slowing the gasses down, not changing the pull of the draft? I guess a baro damper would lower the pressure when set where you want...

Does anyone run a baro on an Englander 28-4000?

Suggestions on running the pipe damper? At the moment I'm guessing wide open to get temps up when starting, then close door, close the pipe damper a bit, then close down air controls?

Thanks again! Just looking to maximize the new stove.




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[brenndatomu]

Are you checking the draft between the damper and the stove?
Generally you don't want the draft over -0.06".
I would say after loading close the door, set the pipe damper to limit draft to -0.06, then after the firebox is hot you can start dialing the stove damper down...once it is set, reset the pipe damper as needed.
But I have a baro and only use my manual damper for windy nights when the baro can't keep up, so you may need to tweak your procedure to suit...

 

[lost in the woods]

Does anyone run a baro on an Englander 28-4000?

Suggestions on running the pipe damper? At the moment I'm guessing wide open to get temps up when starting, then close door, close the pipe damper a bit, then close down air controls?

Thanks again! Just looking to maximize the new stove.




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I have a 28-3500 pre-EPA. I have double wall stove pipe tied into a SS duratech chimney pipe . 20' stack. lots of draft. the install instructions provided said DO NOT run a damper in the stove pipe. I followed the install instructions to a T. I am only getting about 4 hr burn time and im told im losing a ton of heat up through the chimney, however those same ''experts'' who told me about the heat loss were also amazed at the lack of creosote/soot in my chimney pipe. so I think that's he trade off?? hope this info helps, and if you have any advice for me i'd appreciate it

 

[brenndatomu]

I am only getting about 4 hr burn time and im told im losing a ton of heat up through the chimney, however those same ''experts'' who told me about the heat loss were also amazed at the lack of creosote/soot in my chimney pipe.

Yup, heat up the stack...hard to make creosote when the pipe is 4000*
Me personally, I'd have a pipe damper in there so fast it would make your head spin...there has to be a compromise setting between clean stack vs burn time.
Now, with that said...do some research on here, there are a bunch of threads where 28-3500 owners have discussed the hot setup on those units...I know setting the draft control knobs was discussed at length...

 

[Bigeejakes]

So I think I'm going to keep an eye mainly on my chimney temp, I think something is off with my Dwyer manometer, as the damper does not change the reading any noticeable amount... More tinkering needed.

The odd thing to me is that the chimney temps are so low, I'm confused as to why my chimney would be at 300* (taken by IR on the outside of some single wall about 12" up) when the stove is 500* on the front... My only guess is the blower on the stove is running (I'm not used to having a blower on a wood stove).

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[maple1]

Multiply that 300 x 2 and that's more like what internal pipe temps are.

Post up pics of your manometer setup.

 

[brenndatomu]

So I think I'm going to keep an eye mainly on my chimney temp, I think something is off with my Dwyer manometer, as the damper does not change the reading any noticeable amount... More tinkering needed.

The odd thing to me is that the chimney temps are so low, I'm confused as to why my chimney would be at 300* (taken by IR on the outside of some single wall about 12" up) when the stove is 500* on the front... My only guess is the blower on the stove is running (I'm not used to having a blower on a wood stove).

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Have you checked zero on the Dwyer lately?
Have a pic of your Dwyer setup, how its hooked up and all?
300* on the outside of singlewall is roughly 600* internal...that is not low.
EDIT: Sorry, I didn't see Maples post before I replied...

 

[JRHAWK9]

-THIS- is what I bought when I installed my Kuuma. It has been installed since the very first fire. I have it fully inserted in the single wall stove pipe within an inch of where it connects to the collar of the furnace, so it's measuring the temperature of the gases as they come right out of the furnace. Most of the time it does read about 20° higher than the BBQ probe I have inserted about 9" from the collar.

 

[Highbeam]

-THIS- is what I bought when I installed my Kuuma. It has been installed since the very first fire. I have it fully inserted in the single wall stove pipe within an inch of where it connects to the collar of the furnace, so it's measuring the temperature of the gases as they come right out of the furnace. Most of the time it does read about 20° higher than the BBQ probe I have inserted about 9" from the collar.

Ouch! 130$ for a probe meter.

I burn an nc30 modified to be more like a furnace. After the fans kick on, 300 is a normal single wall flue Surface temp when the stove top is 700. As others noted, Flue gas temps run double surface temps so 600 inside from a 700 degree stove passes the sniff test.

 

[Bigeejakes]

Ok: afternoon update! So I had a fire this morning, loaded at 8am - left the damper open, loaded 6 splits - fire was out and down to just a bed of coals in the back at about 12. Reloaded, this time closed the damper all the way, and played with it for a second (more on that later). Stove is now 2 hours in, much better secondaries, same or better heat, same number of splits and it looks like it's barely into the fire... Interested to see how long this one lasts.

Ok so in playing with the damper I noticed that it DOES make a difference in the manometer... About a .02-.03 drop when it is closed.

So open it was reading .11 (pipe at 350 surface) closed it came down to .085. This is still over the .6 max called for in the manual, but better than .11. when it's cruising

I calibrate it to 0 before each time I plan to use it. It's a pretty temporary setup with what I had on hand but I figure it should work.

So here's where I'm at: I had a hard time believing that my draft could be as high as what it's measuring because... It's an outdoor masonry chimney that I added 22' of insulated stainless liner, into a T, through the stone foundation and then a 90 down to the stove.

Based on today's tests so far it's becoming clear to me that I should trust what the manometer is reading... And even with the flue damper, I'm still over draft. I'm thinking a barometric damper may be in my future.

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[Bigeejakes]

Temp on last check... Cruising temps : stove front 550, stove pipe 350.

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[maple1]

Haven't seen it so not sure, but you might be able to swap a 90 for a T and put a baro in that, to get your draft in spec. But I'm not seeing anything wrong with your temps.

 

[JRHAWK9]

Ouch! 130$ for a probe meter.

pretty sure I did not pay nearly that much for it back in early 2014. I was shocked too when last year I went and found that link and seen the price tag.

 

[Bigeejakes]

Update;

My stove install is working much better, and looking much better as I finish things up. I had been experimenting with a damper and temperatures with the single-walled stove pipe that I had laying around, which I connected to some double walled (it happened to fit). All of this was in the previous posts because I didn't want to be randomly drilling holes, and buying a double walled damper if I didn't need it.

I decided I did need a damper (Even though the Englander manual says not to use one). With the double walled damper, and all the correct pipes I am now able to maintain the correct draft easily in the .03-.06 range... which is almost fully closed on the pipe damper. (The single walled damper wasn't perfectly centered and wouldn't close completely... I couldn't get it below .07 which was a noticeable difference from .11)

I'm much happier with the way the stove is burning - and a surprising effect that I have noticed is that now the secondaries fire up much earlier - when the stove front is around the 200*F level. I also have higher flue temps, there is no longer smoke coming from the top of the chimney, fires burn longer... I wouldn't have guessed that by dampering the stove pipe down it would have made such a large difference.

After all of this experimenting - I'll be cleaning the chimney this week (After all of the odd burning I was getting before) and then seeing how long I'm able to burn without build up (this could be the negative of the damper?) Whats your favorite way of cleaning a chimney liner? Normal brush? One of the drill powered ones?

 

[brenndatomu]

Whats your favorite way of cleaning a chimney liner? Normal brush? One of the drill powered ones?

SootEater