Rain cap on OWB stove pipe???

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DLav

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Is anyone using a rain cap on the chimney pipe of their Outdoor wood boiler??

Mine doesn't have one, and I haven't seen any on the OWBs I've looked at. Most people throw a bucket over it in the summer or when they aren't using it.

If you are using a rain cap, did you notice any difference in the way it burned, or wood consumption?
 
iCreek

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Is anyone using a rain cap on the chimney pipe of their Outdoor wood boiler??

Of the 30 - 40s OWB that I have seen driving around Missouri, not one rain cap during the burning season. And yes a metal or plastic bucket seems to be the rain cap for the off season.

What OWB do you have?
 
WVwoodsman

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I have a stainless steel cap on my Mahoning owb. I put it there just out of personal preference because I didn't want any rain getting down into my firebox. Now whether it is effective or not remains to be seen. Since it is on there, I don't put a bucket over the stack during the off season.
 
November Wolf

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I have a stainless steel cap on my Mahoning owb. I put it there just out of personal preference because I didn't want any rain getting down into my firebox. Now whether it is effective or not remains to be seen. Since it is on there, I don't put a bucket over the stack during the off season.


I have heard that a vent cap can cause draft problems and creasote build up. Do you have any problems with yours. I was thinking of maybe trying one out.
 
Slick

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I've been looking at them as a spark arrestor for my central boiler...saw some sparks coming out while stirring things up a few days ago and it worried me a bit...my shop is only 2-3 feet away from the stack. My dealer said he couldn't give a solid answer if it would hurt or help my draft...said some guys have no problems, some guys don't like what it does for their draft.
 
Labman

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I have heard that a vent cap can cause draft problems and creasote build up. Do you have any problems with yours. I was thinking of maybe trying one out.

One way of avoiding that and keeping the rain out is a bigger pipe over it 5 diameters long. For a 4'' stack, use a 20'' length of 5'' pipe. Make brackets to hold it so it comes down just over the top of the stack. Very little rain comes straight down. Nearly all of it will hit the side of the outer pipe, run down and drip off outside the inner pipe. It doesn't add any restriction.
 
KH-1958

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One way of avoiding that and keeping the rain out is a bigger pipe over it 5 diameters long. For a 4'' stack, use a 20'' length of 5'' pipe. Make brackets to hold it so it comes down just over the top of the stack. Very little rain comes straight down. Nearly all of it will hit the side of the outer pipe, run down and drip off outside the inner pipe. It doesn't add any restriction.

Good Point! Our township requires a higher stack based on how far the OWB is from the house. So we put a 4 ft stack on the OWB. I have noticed that the rain does not affect the boiler and we had a lot of it last weekend. :clap:
 
WVwoodsman

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Wolf, I have not had any creosote problems this year, but I have been keeping the water temp. around 165-170 when it's not as cold outside. Doing this causes the owb to cycle more often which eliminates creosote build up. This is my second winter heating with an owb and I have learned a lot since I fist got it. Last spring as it was warming up there seemed to be a lot of creosote because I didn't adjust my aquastat accordingly which resulted in longer periods of blower inactivity and ultimately led to more creosote. As for the height if the stack it is 6 feet. I used stainless double wall which cost a little more, but I wanted it to last. Before firing up the unit last fall, I pulled the whole stack off and cleaned it out really well with a metal bristled flue brush. I cleaned up really well. I hope this answered your questions.
 
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Sawmill

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When we bought our stove 3 years ago I also bought a cap mainly as a spark arester because our house is in the woods. I burn our stove year around and did not have any creosote problems. The problem that I had was on days when it was humid out moisture dripped off the cap and onto the roof of the stove. This moisture must of had the acids from the wood in it and it started to rust my roof. Luckily I caught it in time and sanded it and repainted the whole roof with Rust Olem paint. I talked to my dealer and he said that was a big problem with using a cap. I took it off and may use it on a limited basis in the summer. I did not notice any difference in the wood usage or the way the stove was burning.
 
November Wolf

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I've been looking at them as a spark arrestor for my central boiler...saw some sparks coming out while stirring things up a few days ago and it worried me a bit...my shop is only 2-3 feet away from the stack. My dealer said he couldn't give a solid answer if it would hurt or help my draft...said some guys have no problems, some guys don't like what it does for their draft.

One way of avoiding that and keeping the rain out is a bigger pipe over it 5 diameters long. For a 4'' stack, use a 20'' length of 5'' pipe. Make brackets to hold it so it comes down just over the top of the stack. Very little rain comes straight down. Nearly all of it will hit the side of the outer pipe, run down and drip off outside the inner pipe. It doesn't add any restriction.

Wolf, I have not had any creosote problems this year, but I have been keeping the water temp. around 165-170 when it's not as cold outside. Doing this causes the owb to cycle more often which eliminates creosote build up. This is my second winter heating with an owb and I have learned a lot since I fist got it. Last spring as it was warming up there seemed to be a lot of creosote because I didn't adjust my aquastat accordingly which resulted in longer periods of blower inactivity and ultimately led to more creosote. As for the height if the stack it is 6 feet. I used stainless double wall which cost a little more, but I wanted it to last. Before firing up the unit last fall, I pulled the whole stack off and cleaned it out really well with a metal bristled flue brush. I cleaned up really well. I hope this answered your questions.

When we bought our stove 3 years ago I also bought a cap mainly as a spark arester because our house is in the woods. I burn our stove year around and did not have any creosote problems. The problem that I had was on days when it was humid out moisture dripped off the cap and onto the roof of the stove. This moisture must of had the acids from the wood in it and it started to rust my roof. Luckily I caught it in time and sanded it and repainted the whole roof with Rust Olem paint. I talked to my dealer and he said that was a big problem with using a cap. I took it off and may use it on a limited basis in the summer. I did not notice any difference in the wood usage or the way the stove was burning.

Thanks for the info guys. I may try one just to be on the safe side when the snow melts. It can get really dry around here in the spring.
 
abohac

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I have one that I got from my Woodmaster dealer. Cost me an arm and a leg and I think it causes even more smoke in my face by directing it downward. Keeps the rain out though.
 
ericjeeper

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I have one

I am using 8 inch insulated pipe.. Therefore an inch of rain in an 8 inch hole would be quite a bit of water in the bottom of my ashes..
Plus I like the way it looks when I leave the boiler door open to burn out the creosote after a warm spell.
The reason I am using 8 inch is because the two sections of pipe were free.. But man did they bend me over when I bought that stainless steel cap.. Wow. they could have at least used some sort of LUBE. LOL
 
windthrown

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The CB 4436 that we had did not come with a raincap/sparc screen. The dealer said that the ones they had then sucked and did not advise getting one. I used a 5 gallon bucket over it in summer for 2 years. Then 2 years ago I got a replacement controller from the dealer (for free, he extended the one year warantee on it) and said they they (Central Boiler) had a better/newer rain cap/sparc arrester so we bought one and put it on. It worked good, but the sparc screen burns out pretty fast with any flames coming out the top. The rain cap is still working fine on it though. That place gets about 8 feet of rain a year. So a minor amount of heat saved. Also easier to shut it down in summer, no need to put the 5 gallon plastic bucket over it any more.
 
Slick

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Yeah these things are more expensive than I thought they would be...anyone got any pictures of ones they are or have used?
 
Laird

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Here is what I use. It is stainless and has a piece inside you can't see in the pic that covers the opening for rain protection.

I have never figured out how to add a pic to the body of my post and have to do it as an attachment. If anyone can help out I would appreciate it.
 
November Wolf

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Laird

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attachment.php


Thank you!
 
Hawken

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I just put one on two weeks ago. I ran my stove three weeks before that without. I do not see a problem with draft or build up. I have seen some sparks shooting out a few times and thought better safe than sorry.
 

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