Outdoor Wood Burner

[Real Fast Travis]

Hey everybody, question for those of you that use outdoor burners.
I am fairly new to this, this will be my third winter using one. Previous owner said he used it exclusively to heat the house, no supplemental gas or anything.

My question is, how much wood do you use? Or, how often do you need to load it?

I belive I have the Big Johnson stove, it looks to have a three foot box inside of wood. Two blowers, one on the wood, one under. I keep the water temp set around 170-180 F. I am in Northwest Illinois, so it does get cold in the heart of winter.

I find that I have to load this unit 4 times a day, once and awhile I can get by with three times, but only if the temps are closer to 35-40F. Sometimes 5 loads would be needed, on the really cold nights, like below zero.

Is that normal? Seems like a lot of wood. I don't have an accurate record of how much wood I go through a season, but I guess 12-15 cord. Most of it is dry and well seasoned, wood is from storm blow down tress that have been down for years. I do burn some green stuff, but not much honestly. I do burn a mix of woods though, maybe 60-17% hardwoods, the rest is softwoods.

I feel like the previous owner, and my neighbors only burn the wood at night, and switch over to gas durning the day. I rarely see smoke coming from their units mid day, and mine is burning constantly.

Should I change the water temp?

Only other issue I can think of is it does not have a chimney, but previous owner said that wasn't a concern. Is the wind blowing down in it wasting my wood?

Any tips or suggestions would be greatly appreciated.
Thank you

 

[Motorsen]

I'm not familiar with OWB's as I heat by a stove with watertank to heat my floors. But the experts will need to know the size of the Castle and how well it's insulated. Do you have an heat exchanger for domestic hot water etc.

Motorsen

 

[NSMaple1]

Can't offer much without knowing your heat load.

Do you know exactly what you have for underground piping? Ever measure temp drops between boiler & house?

 

[cantoo]

When winds aren't high mine very seldom fires during the day because we are usually away and the heat is turned down. On windy days it will fire but not very often. We usually burn poplar during the day and throw in Ash at night. I'm heating 2 houses but both are insulated pretty well. I never keep track of what I burn either, I burn a lot of crap including skids.
If yours is firing that often and burning that much wood then you have an issue. Could be one thing or several things, crappy underground pipe, poor insulation in house, poor windows and doors, broken thermostat on boiler. Divide the complete system and conquer to find out where your system is going wrong. How hot do you keep your house during the day?

 

[PSUplowboy]

Just wondering how much you're putting in to fill it. I can easily put a wheelbarrow load in mine when it's low. If you're putting in 4 to 5+ wheelbarrow loads a day, I'd think that would be more than 15 cord. Seems like a lot of wood. I check mine twice a day. This will be the eighth winter for my boiler. Sometimes really dry wood seems to burn up fast on windy days, but not to the point of filling it that often. Like others have said- I'd be looking at the temperature drop from boiler to house.

 

[polkat]

I only touch mine twice a day before i go to work 4:45 and just before i go to bed 10:00. I throw in 4-5 splits every time . If its really cold below zero i'll check it right when i get home and throw in a split or two but i do add a little more when its below zero

 

[Timbercreek]

couple of things. Check for air leaks. make sure the fans turn off and on, dampers open and close. air leaks will consume wood as the draft will pull air in and keep burning even when not needed.
also, check the aquastat, make sure it cycles the boiler on and off.
also, a OWB does better with a half load of wood then it does a full load. reason being, more surface area to exchange heat to the water, no cold wood touching the firebox.
its either that or someone SERIOUSLY undersized your OWB to heatload.
and just for hahas, try mixing the wood up, dont give it all perfectly dry seasoned splits. throw a layer on bottom to light up good, then put some whole rounds or wet stuff on top.
i use to load my OWB like this: splits, rounds, GREEN. the green on top would buy me time, the heat from bellow would dry it and it wouldnt light up for a cpl hours.

ALSO, have you cleaned the HEAT EXCHANGER or UPPER FLUE depending on boiler design?
heatmor has a upper gasification flue in the middle of water jacket, does most of the heating, and should be cleaned once a month.
also, whats your ash removal schedule? all these things add up in a OWB.

 

[Timbercreek]

okay, 275 gal of water, theres no way your undersized.
whats this BYPASS crap they speak of?
are you running it right? i have no idea what is right or wrong, but it SOUNDS like they had issues with people leaving it on and not getting any heat, they ELIMINATED it on new models.
if i had to guess, bypass should only be used or on when loading, and off when making heat.
had a uncle that did this once. simply confused which way was off and on for the damper on his indoor gasifier. wondering why he was getting no heat.
another thing to look at if the boiler isnt at fault, would be compromised pipe from boiler to house. if your line is below water table, and was somehow compromised, groundwater could have seeped in and be robbing all your heat. this would be simple to see via temp drops from boiler to house and back.
hope you get it, thats insane. i heated 3800sf with NO insulation drafty ol farmhouse on a lil heatmor 100css, and i was only loading every 12 hrs at my worst, and thats only 89gal of water and 100k btu

 

[Real Fast Travis]

Wow! So much information.... Let me try to answer everyone.

House is 100 years old, isolated as such. Two story, not sure exact square footage, maybe 2000sf. Thermos for the house is set at 67-68 degrees, 24/7. Windows have been updated, but that is about it. The house is heat with old baseboard radiators, the heat exchanger is in the basement by the gas boiler.
How would I check temp drops there? You can touch the heat exchanger, but not for long, it is hot. Temp at the burner is around 180, so I don't think I am loosing much heat there.

It does not heat my domestic hot water.

I do fill it full every time, so I can try filling less. I have a .7 cubic foot yard cart, I fill it to the top, that is a load for the stove. I do that at minimum 3 times a day, at most 5, average 4 times a day.

Pretty sure I'm using the bypass correctly, but I am going to google it to make sure. Blowers kick on and off as they should. Not aware of any air leaks, but not sure how I would check for those, smoke only comes out through the chimney, I don't see it coming out anywhere else.

Not sure about cleaning the heat exchanger or upper flue... I don't think I have those on the boiler. It is a pretty simple unit, just a big fire box with a water tank around it. But I will research that.

Ash is removed daily, from under the fire box.


The previous owner took me through a very detailed tour of how to use and maintain it, none of those things were mentioned.

I will replace the door seal before i fire it up this season, just to make sure it is good.


Thanks for all the suggestions everyone, I really appreciate it. It sounds like I am burning more wood than I should be. I've got some research to do.

 

[NSMaple1]

How would I check temp drops there? You can touch the heat exchanger, but not for long, it is hot. Temp at the burner is around 180, so I don't think I am loosing much heat there.

With a thermometer, of some kind. A good IR one might work well, but they don't read shiney surfaces well (spot of flat black pain where you're reading fixes that). Otherwise something like a smoker thermometer with a probe - just get the probe flat on a pipe surface & tie some pipe insulation around it to get a good reading. If you can touch the exchanger for any amount of time at all, that doesn't sound good. If your OWB pump runs 24/7, I would bet most of your heat is going right into the ground thru those pipes. So what kind of pipes are they exactly? Didn't answer that - pic would help, of where the leave/enter the ground. Does your pump run all the time? With crappy pipe plus a pump running all the time, you would be lucky to get 20% of the heat that is in your wood, into your house.

I have a .7 cubic foot yard cart, I fill it to the top, that is a load for the stove. I do that at minimum 3 times a day, at most 5, average 4 times a day.

That doesn't sound right, at all. Do you mean 7 cu.ft.? .7 would be like one stick of wood. If it's 7, 4 times per day - that's one full cord every 6 days. That's a huge amount of wood.

The previous owner took me through a very detailed tour of how to use and maintain it, none of those things were mentioned.

Was any kind of cleaning explained? Any decently efficient boiler will need regular cleaning of heat exchanger surfaces. But after just looking at what I think is their website, it sounds like an ordinary water jacketed boiler - and they are not efficient to start with.

 

[Real Fast Travis]

How would I check temp drops there? You can touch the heat exchanger, but not for long, it is hot. Temp at the burner is around 180, so I don't think I am loosing much heat there.

With a thermometer, of some kind. A good IR one might work well, but they don't read shiney surfaces well (spot of flat black pain where you're reading fixes that). Otherwise something like a smoker thermometer with a probe - just get the probe flat on a pipe surface & tie some pipe insulation around it to get a good reading. If you can touch the exchanger for any amount of time at all, that doesn't sound good. If your OWB pump runs 24/7, I would bet most of your heat is going right into the ground thru those pipes. So what kind of pipes are they exactly? Didn't answer that - pic would help, of where the leave/enter the ground. Does your pump run all the time? With crappy pipe plus a pump running all the time, you would be lucky to get 20% of the heat that is in your wood, into your house.

I have a .7 cubic foot yard cart, I fill it to the top, that is a load for the stove. I do that at minimum 3 times a day, at most 5, average 4 times a day.

That doesn't sound right, at all. Do you mean 7 cu.ft.? .7 would be like one stick of wood. If it's 7, 4 times per day - that's one full cord every 6 days. That's a huge amount of wood.

The previous owner took me through a very detailed tour of how to use and maintain it, none of those things were mentioned.

Was any kind of cleaning explained? Any decently efficient boiler will need regular cleaning of heat exchanger surfaces. But after just looking at what I think is their website, it sounds like an ordinary water jacketed boiler - and they are not efficient to start with.

Ok, I can try using a thermometer, I have several.

As for the pipe, it is 1" or 1 1/2" pex, I assume it runs in some sort of insulation, but I don't know for sure. I'll poke around and see it I can figure that out. But yes, the pump runs 24/7 from the burner to the exchanger in the house. there is also a set of pipes that run to the garage, but I have that turned of, so it should not be draining any heat from the water.


Correct, 7 cubic foot cart, my bad... and yeah, I thought it was a lot of wood.

The only cleaning he said to do was to scrap down the inside where you see build up. around the door, etc... No flue that I am aware of.
Correct, it is just a water jacket design, and I have learned from the internet it is not the best design, but it is what I have, so I am trying to make the best of it.




So, assuming water temp is 180 at the stove, and it is 200-300 feet from the house, what should I expect to see for temps at the exchanger in the house?

Thank you!

 

[djones]

I would set your cut in temp down to 160° from 170° and cut down on the amount of time that the blowers are kicking on. My house was built in 1857 with little insulation. We have upgraded some areas of the house but not all. Some windows are new, some not. At 1700 sq. ft. it takes a bit of heat to keep the temps at 70°. I fill my boiler 3 times a day, morning, afternoon and at bedtime. At bedtime in the early and later parts of the heating season I turn my blower off and just let it naturally aspirate till morning. I go through on average 16 cord a year using lots of pine and what ever hardwoods I can find that are dead or down, beech, ash, some maple. I use my soft woods for the early and late parts of the burning season and the hard woods for the bitter cold part. I have been known to use 6 cords just for Jan. and Feb. if it's cold enough. My boiler provides house heat and domestic hot water. If I was better insulated I could probably save a few cord per year but that would require that I gut the house and start from scratch. At my age, that ain't happening.

 

[Real Fast Travis]

I would set your cut in temp down to 160° from 170° and cut down on the amount of time that the blowers are kicking on. My house was built in 1857 with little insulation. We have upgraded some areas of the house but not all. Some windows are new, some not. At 1700 sq. ft. it takes a bit of heat to keep the temps at 70°. I fill my boiler 3 times a day, morning, afternoon and at bedtime. At bedtime in the early and later parts of the heating season I turn my blower off and just let it naturally aspirate till morning. I go through on average 16 cord a year using lots of pine and what ever hardwoods I can find that are dead or down, beech, ash, some maple. I use my soft woods for the early and late parts of the burning season and the hard woods for the bitter cold part. I have been known to use 6 cords just for Jan. and Feb. if it's cold enough. My boiler provides house heat and domestic hot water. If I was better insulated I could probably save a few cord per year but that would require that I gut the house and start from scratch. At my age, that ain't happening.

I don't believe I can adjust the blower times/cycles. They come on and off based on the water temp. I can try lowering the temp some to see if that helps.
It sounds like we burn about the same, with the same type of home, same types of wood.
Maybe I'm not too far off in my consumption? Maybe it is just because the stove is not that efficient in the first place?

 

[djones]

I don't believe I can adjust the blower times/cycles. They come on and off based on the water temp. I can try lowering the temp some to see if that helps.
It sounds like we burn about the same, with the same type of home, same types of wood.
Maybe I'm not too far off in my consumption? Maybe it is just because the stove is not that efficient in the first place?

I installed a cut out switch for my blower so that I had some control over it's cycling. It's just a manual toggle switch that I put in line after the damper control solenoid. That way the damper still operates when air is called for but the blower won't come on. It is especially useful in the early and late season when the nights are not too cool. Once the really cold weather hits then the blower is turned on at all burning cycles. The hard wood needs a little extra air to put out the heat. Since the switch is located out of the weather I probably should install a small indicator light to remind me that it is on / off. That would save me some late night treks through the snow to check on it.

 

[Real Fast Travis]

I installed a cut out switch for my blower so that I had some control over it's cycling. It's just a manual toggle switch that I put in line after the damper control solenoid. That way the damper still operates when air is called for but the blower won't come on. It is especially useful in the early and late season when the nights are not too cool. Once the really cold weather hits then the blower is turned on at all burning cycles. The hard wood needs a little extra air to put out the heat. Since the switch is located out of the weather I probably should install a small indicator light to remind me that it is on / off. That would save me some late night treks through the snow to check on it.

Yeah, yours must be different than mine. I have no dampers, just two blowers. One blows under the fire, one on top, they cycle on and off as the water temp drops/rises.

 

[djones]

Yeah, yours must be different than mine. I have no dampers, just two blowers. One blows under the fire, one on top, they cycle on and off as the water temp drops/rises.

You can still install a separate switch or two to operate the blowers if you wanted to.

 

[ash man]

My stove is 125' from the house and I have thermoflex pipe( not quite as good as thermopex) and I'm losing @5°. If your 300' and have inadequately insulated pex pipe your heat lose could be huge. I learned the hard way and had to replace my homemade pipe after only 2 seasons and it's made a huge difference in the amount of wood I burn.

 

[Real Fast Travis]

You can still install a separate switch or two to operate the blowers if you wanted to.

But without the blowers, I don't think the fire would get hot enough, like I said, they only kick on long enough to get the fire going to heat the water, like 20-3- minutes, then shut off.

My stove is 125' from the house and I have thermoflex pipe( not quite as good as thermopex) and I'm losing @5°. If your 300' and have inadequately insulated pex pipe your heat lose could be huge. I learned the hard way and had to replace my homemade pipe after only 2 seasons and it's made a huge difference in the amount of wood I burn.

It is the factory piping, in some sort of insulated ductwork. Once I fire it up for the season, I'll check toes how much temp I am loosing.

 

[djones]

But without the blowers, I don't think the fire would get hot enough, like I said, they only kick on long enough to get the fire going to heat the water, like 20-3- minutes, then shut off.

If it takes 20 to 30 minutes to heat your water from 170° to 180° , then you do indeed have a problem, especially with 2 blowers going to keep the fire hot. Disregard anything I have said because it will not help you. You need some specialized attention beyond what I can suggest. Good luck.

 

[Real Fast Travis]

If it takes 20 to 30 minutes to heat your water from 170° to 180° , then you do indeed have a problem, especially with 2 blowers going to keep the fire hot. Disregard anything I have said because it will not help you. You need some specialized attention beyond what I can suggest. Good luck.

How long should it take?