Not Worth cleaning the chimney again this year

[peakbagger]

I will start out with a disclaimer, my setup is very untypical for a wood burning setup and just because I dont have to clean my chimney yearly its highly likely most folks do. Nevertheless with the right chimney design and operation, chimneys may not need to be cleaned yearly although I do inspect mine yearly with a mirror.

I have an older Burnham Wood/Coal boiler with 550 gallons of storage. Its hooked to 8x10 rectangular tile flue in a standard concrete block chimney. There is an adajcent oil boiler flue, but the boiler is a cold start so its cold most of the time. The boiler is in the basement and runs through 2 heated floors and a 6' unheated attic to a high point on the house. The outdoor portion sticks up about 4 feet from the ridge pole.

I have never run coal and the shaker grate was long gone when I got the boiler so a friend made me a grate. All air comes up from the bottom of the fire and the grate sits down at the base of a refractory lined triangular pit. There are some steel smoke shelves that redirect the flames prior to going through a bank of vertical tubes with the remnants of turbulators. Its not super efficient compared to newer designs.

I run the boiler full tilt with 1.5 to 2 year old dry wood until the storage is up to temp. There is a motorized air damper if the boiler overheats but the goal is to never have it shut when the boiler is hot. As the storage peaks out I can dump heat into a domestic hot water tank or into the house. I use a minisplit in shoulder seasons so generally only run it when it gets consistently cold. The bottom location of the grate and the air source below it means I get no coals and if I dont feed it quick enough when the wood burns out I might have to relight it. The ash is fine dust with no coals and it dumps into a lower air chamber so it doesn't build up on the grate. I would like to retrofit it with heated secondary air but the design prevents me from doing it. I run about 2.5 to 3.5 cords a year.

Its not just the boiler as I had a papa bear clone for several years and a VC Defiant after that before the boiler. In total since 1988 I have cleaned the chimney three times and generally it was out of guilt more than need. I usually did small loads with the stoves during shoulder season and rarely used the dampers to cut back on load.

My reasons why I think I dont need yearly cleaning while most do; the big things are an interior chimney and inefficient stoves and boiler. I expect the stack temp stays warm enough that any condensables stay as superheated vapor while in the stack. The other reason is I have always tried to burn hot fires. The stoves and boiler are in a partially insulated basement and I can usually get away with hot fast fires. I rarely if ever banked a stove for overnight as the house is well insulated and even in cold weather, it stays warm enough all night so that I really dont need an overnight fire. Obviously with the boiler and storage no need for overnight burns. The one downside is I have to relight the boiler every time I use it. That means I need to stock up on newspaper and kindling.

 

[BoiledOver]

Congrats to you! We have similar flue results. Since getting the Eko, I have brushed the flue twice even though it wasn't really needed. I will visually check it each spring and when the time comes, brush it out. Batch burning a gasser is the bomb.

 

[woodsmaster]

Haven't cleaned mine in three years... still looks good !

 

[maple1]

Same here - now going into year 6. I used to have to get up on my 2 story roof 3 or 4 times a year. Now haven't been up there since 2012.

That's with a gasser though, which is supposed to be a clean burner. However, your experience re-affirms my feelings that if you have a decently designed 'conventional dirty' wood burner that has decent burn abilities (under fire air) and good heat transfer ability (exchange tubes), you would likely be better served by adding storage rather than upgrading your boiler. Storage is the bigger game changer - to me.

 

[peakbagger]

I would love to buy a new froling or similar unit but hard to justify since I use so little wood I got this boiler free from a poor installation and it appears to be built like a tank (and weighs like one). I did try to run it without storage for a few years and unless it was real cold out it was a PITA unless I let it use the air damper to cut the output when there was no heat demand. After watching the chimney a few times when the damper shut and seeing the cloud of tan smoke (which is usually a sign of CO and incomplete combustion), I switched back to the woodstove. The winter I got the storage, I cut my wood usage by a third and the oil boiler pretty well stopped running except when I am gone for a few days in very cold weather. I have two 275 gallon oil tanks and plan to remove both of them and put in a Roth tank (broken link removed to http://www.roth-usa.com/products_dwt.cfm) to free up space and do away with any potential for tank leaks.

 

[Bad LP]

In colder climates an interior chimney is key to avoid hot smoke and gases coming in contact with a sub freezing masonry block that is going to take a very long time to come up to a temperature that won't condense. Then of course the risk of cracking tiles is also much lower.

 

[peakbagger]

My neighbor has the exact opposite setup as mine. He has a floor to cathedral ceiling stone fireplace in his living room that acts as an exterior wall so the majority of the stone structure is outdoors with an interior face floor to ceiling. The mason ran a basement flue up through the stone next to the main flue which is at the back of the chimney outdoors. He got a used older Tarm and ran it without storage. He had numerous chimney fires even though he left a ladder up against the chimney and would clean it frequently. He finally shattered the boiler tiles in a chimney fire and put in a SS liner. That lasted a couple of years and several chimney fires until he melted that. Unfortunately he ultimately put in an OWB and now pollutes the neighborhood. I think he burns 6 to 8 cords a year of 6 month wood.

 

[salecker]

Mine was clean like normal last weekend.I did clean my boiler tubes though.Last Sunday was the start of wood burning for us.Boiler sat dormant since mid April.Everything worked like it should and our butts are warmed with carbon neutral fuel for the rest of the winter.

 

[Bad LP]

My neighbor has the exact opposite setup as mine. He has a floor to cathedral ceiling stone fireplace in his living room that acts as an exterior wall so the majority of the stone structure is outdoors with an interior face floor to ceiling. The mason ran a basement flue up through the stone next to the main flue which is at the back of the chimney outdoors. He got a used older Tarm and ran it without storage. He had numerous chimney fires even though he left a ladder up against the chimney and would clean it frequently. He finally shattered the boiler tiles in a chimney fire and put in a SS liner. That lasted a couple of years and several chimney fires until he melted that. Unfortunately he ultimately put in an OWB and now pollutes the neighborhood. I think he burns 6 to 8 cords a year of 6 month wood.

Not to mention that floor to ceiling heat (or should I write cold) sink. Might as well leave a couple of windows open.