Newby Questions - Wood furnace.

[ChevyGuy]

Hello Everyone,
Not new to the site as I usually am posting about pellet stoves. But in the last month I installed a Englander 28-3500 wood burning furnace in my 2 story carriage house. The furnace is on the bottom floor on concrete, in a small furnace room with required firecode sheetrock, fire door, ect. Installed double walled black pipe from furnace up through the second floor and the double walled stainless class A through the roof and 10' above the roof to get the required 24" above anything within 10' deal. Actually went just a little higher than required.
I have awesome draft and get the wood burning nice. Burning wood is new to me so I have a few questions. On the front of this unit is a temperture guage and it has a designated burn area marked off of between 275 and 575 for the range I should stay in. Too low and you create creasote, to high you over fire. I had about 15 burn days so far and getting used to this furnace. The manual for the stove and post on here state that I should get about 6 to 8 hours of burn out of a load of wood, filling the furnace. I am lucky if I get 2 hours. I am continually monitoring the burn and closing the draft controls to keep it above 300 degrees. It has to be burning pretty strong for me to get it above 350. I get it so that the draft control on the ash door is almost closed and the chimney draft is 4 fifth closed. If I close any more the temp goes below the "Burn range" on the guage. Having it set like this gives me about 2 hours before the wood is down to ashes. What am I not getting here? The wood is Ash and Cherry, cut in late October. I don't think it is because the wood is too dry. Any thoughts? I was thinking that the temperature guage was broken but the thermostat (seperate from the temp guage) on the unit doesn't turn the circulation fan on if the guage reads under 275.
Another question. Because this is a garage and I am only working during the day, and am only getting 2 hours of burn out of a load of wood, the fire goes out every night after I finish work. So all the start up and cool down time this system gets every day has plenty of time in the "Creasote making" temperature range. How concerned do I have to be about this? How often should I be checking the insides of the chimney pipes? My plan was, if I get the 6 to 8 hours of burn per load, to fill it before bed and keep it burning 24/7 and not have this amount of down time. It ain't workin' out dat way right about now. Thanks for any suggestions.

 

[Simonkenton]

Wood 3 months old is probably not dry enough. Go to Lowes and buy the $29 moisture meter with prongs on it and check moisture content of wood. You need to get it down to around 20 percent.

 

[begreen]

To measure the wood moisture you need to get the split to room temp, then resplit it in half. Test on the freshly exposed grain and not on the end grain.

 

[ChevyGuy]

Wood 3 months old is probably not dry enough. Go to Lowes and buy the $29 moisture meter with prongs on it and check moisture content of wood. You need to get it down to around 20 percent.

If the wood was not dry enough wouldn't it just smolder and not burn well? My sister has been bruning for 20 years and when she gets wood that isn't dry it sits in there and takes forever to burn and the heat output is horrible. Mine burns fast and hot. TOO FAST.

 

[begreen]

We need more data. Without a moisture measurement we can only speculate. Wood cut only a few months earlier leads to the strong suspicion that it is not seasoned. With drier wood you may be able to allow less air and yet have a hotter fire. Was the wood standing dead?

Strong draft could also be playing into this question and somewhat masking the issue with the wood. Has the draft been measured? If it is far above spec then a damper may need to be added to the connector pipe. Another data point would be to measure the connector pipe temp. If it is high that could be where a good portion of the heat is going. For example if you are reading 300F on the furnace door and 500F on the connector pipe surface (meaning a flue gas temp around 750-900F), then most of the heat is going up the chimney.

 

[ChevyGuy]

We need more data. Without a moisture measurement we can only speculate. Wood cut only a few months earlier leads to the strong suspicion that it is not seasoned. With drier wood you may be able to allow less air and yet have a hotter fire. Was the wood standing dead?

Strong draft could also be playing into this question and somewhat masking the issue with the wood. Has the draft been measured? If it is far above spec then a damper may need to be added to the connector pipe. Another data point would be to measure the connector pipe temp. If it is high that could be where a good portion of the heat is going. For example if you are reading 300F on the furnace door and 500F on the connector pipe surface (meaning a flue gas temp around 750-900F), then most of the heat is going up the chimney.

I thank you for your input. Hearing that to much heat could be going up the chimney got me trying something. I totally closed the top damper control and only had the ash door control open a little. Results were that the temp on the guage went up to 400 (Which in higher than before) and the load lasted nearly 4 hours this time. Double what I had before. So you got me going in the right direction. I own a good quality moisture ,meter so I probed the core on about 20 of the pieces of wood. Ranged from 11% up to 15%. Seems a little to low, like kiln dried, do I will get fresh batteries tomorrow and scan again. I took my laser temperature guage and took a reading of the temp on the outside surface of the double walled chimney just above the furnace outlet. Got a reading of 225 degees.
About measuring the draft.... Where would I get a guage for doing that and how is it Done?

 

[bholler]

Installed double walled black pipe from furnace up through the second floor and the double walled stainless class A through the roof and 10' above the roof to get the required 24" above anything within 10' deal. Actually went just a little higher than required.

So you have stove pipe running through the floor?

 

[brenndatomu]

About measuring the draft.... Where would I get a guage for doing that and how is it Done?

Look for my ad over in the for sale section...I have a couple left...and we can walk you through using it...pretty easy really

 

[ChevyGuy]

So you have stove pipe running through the floor?

Yes. Through a 2' x 2' hole with sheet steel as a fire block. I have more than the 6" required clearances from the framing.

 

[bholler]

Yes. Through a 2' x 2' hole with sheet steel as a fire block. I have more than the 6" required clearances from the framing.

Still not allowed you cant have connector pipe passing through walls or floors

 

[ChevyGuy]

Still not allowed you cant have connector pipe passing through walls or floors

I tend to believe you are wrong. I submitted plans to my building inspector with all details of pipes, parts and clearances and he approved them. Fire inspector also looked at the plans and said it was good.

 

[bholler]

I tend to believe you are wrong. I submitted plans to my building inspector with all details of pipes, parts and clearances and he approved them. Fire inspector also looked at the plans and said it was good.

You can beleive what ever you like but you are not allowed to run connector pipe through floors or walls by code.

 

[maple1]

I tend to believe you are wrong. I submitted plans to my building inspector with all details of pipes, parts and clearances and he approved them. Fire inspector also looked at the plans and said it was good.

I'm not an expert but I would bet the inspectors somehow missed what you were really doing or had their minds seriously elsewhere when they did their looking. If you really want to test the waters, you could give your insurance agent a call & see what they say. I really hope nothing bad happens because I suspect your insurance company would call that out immediately if a claim were involved, and not allow the claim.

 

[lexybird]

2 hours burn time ? That doesn't sound right . I owned a 28-3500 and if full you can easily get 8-10 with seasoned hardwood and proper settings . You are basing your burn time off of a cheap magnetic temperature gage aren't you ? Those are no way to adjust your controls by . Lots of threads on how to operate this furnace for best results . Try using the search and read every page . Your doing something wrong . Even a bonfire in the open with 7 cubic feet of hard wood lasts longer than 2 hours

 

[bholler]

tend to believe you are wrong.

Here is the code from nfpa 211

9.7.2
A chimney connector or vent connector shall not pass
through any floor or ceiling or through a fire wall or fire
partition.

 

[hondaracer2oo4]

Can you tell us a little more about the history of your firewood? You said it was cut in October, what does that mean? Also in order to get the moisture content of firewood you will need to take a piece and split the it again. Now take 2-3 measurements with the probes perpendicular to the grain on the face of the freshly split piece. When I have probed green wood on the end of the piece without splitting the wood I have gotten similar numbers to your 11-15. The actual moisture levels inside the freshly split wood was around 40%

 

[hondaracer2oo4]

Where did this guy go?

 

[leftyz]

Probably need to run it with the lower vent all the way closed, getting too much air and burning that dry wood up too fast. Also how much wood are you loading? The manual says to only load up to the top of the firebrick but I put in as much as can possibly fit.

I just got my 28-3500 installed and I'm trying to figure it all out too, hope you get it figured out, post what you find to help out others like me!

 

[lost in the woods]

I have the the same wood burning stove and yeah the instruction manual says 6-8 hours burn time but I haven't achieved that yet unless I damper everything wayyyyy back. . . I do not have a damper on my stovepipe as the instruction/installation manual says do not install a damper on stovepipe. .. I feel that some heat is lost up through the chimney but the trade off is that I have like NO creosote in the duratech chimney pipe. . . to make things even more confusing the installation manual for the stove and the duratech chimney pipe shows how to install your chimney straight up through your floors and ceilings OR out the side and up the exterior wall of your house. . . with all that being said, bholler 's word is to be trusted. him and his dad are THE authority on this kind of stuff in our area. hope this information helps

 

[bholler]

to make things even more confusing the installation manual for the stove and the duratech chimney pipe shows how to install your chimney straight up through your floors and ceilings OR out the side and up the exterior wall of your house

Chimney pipe up through floors is fine but he has double wall stove pipe run up through the floor. That is not allowed by code.
Are you a customer of ours? Regardless thank you for the kind words

 

[lost in the woods]

no but I live close by and we have some mutual friends

 

[Master sweep walt]

Chimney pipe up through floors is fine but he has double wall stove pipe run up through the floor. That is not allowed by code.
Are you a customer of ours? Regardless thank you for the kind words

Only class a chimney , air cooled
is allowed to pass between floors that are combustible and it must be boxed in with the proper clearances it in a open living space or storage space .

 

[bholler]

Only class a chimney , air cooled
is allowed to pass between floors that are combustible and it must be boxed in with the proper clearances it in a open living space or storage space .

Yes that is what i said. Chimney pipe not stove pipe is allowed but most are not air cooled most are insulated.