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Chimney caps

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rbd33
rbd33 Member Posts: 14
edited August 2022 in Chimneys & Flues
I just had the chimney for my oil boiler replaced. Previously I had a 3 layer air cooled galvanized metal chimney that was covered by a prefab metal housing made to look like bricks with a chimney cap. It was replaced by a Selkirk Ultra Temp Stainless Steel Chimney. There was a lot of soot in the old chimney liner and the outer layer was rusted with some corrosion and holes. The chimney person told me that I had had the wrong kind of cap, that it was low bent and made for gas and it should have been swapped for a high vent cap for the right draft for oil. Is this a thing?  I called the roofing company that installed the old cap and he told me chimney people lie because they want you to get a new chimney and that they’ve installed thousands of these and no one has ever complained of problems. I replied that people don’t complain because they don’t know. They don’t necessarily know if their boiler is working harder, or dirtier and if a chimney cap could be a contributing factor. He also said he consulted chimney people who confirmed that their chimney caps were just fine. I guess the chimney people he consulted were not among the ones who lie. In any case are there caps that should be used for gas that should NOT be used for oil? And why?

Comments

  • rbd33
    rbd33 Member Posts: 14
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    This is the old chimney housing and cap. 
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
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    This is a question for the expert @Bob Harper.
    As a side note, I don't want chimney info from a roofer.

    There was an error rendering this rich post.

    MikeAmann
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,060
    edited August 2022
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    This sounds suspiciously like a Question that I recently answered this way

    The "Dirt" that you are talking about... What did it consist of? That would help pinpoint the source. If the dirt was leaves, that would have a different source that if it were mostly carbon (SOOT).

    What you are describing sounds like a Class A manufactured chimney. A liner would be a single wall metal pipe that is inserted in a masonry chimney. Sometimes the terracotta sections of the inside of a masonry chimney are referred to as a liner.

    This might be what you are referring to: http://www.csiworldwide.com/AirJet/All-Fuel Chimney.htm. These manufactured chimneys come with detailed installation instructions in order to make them safe and weather proof. A roofer may not be the best person to install a chimney. You may want to contact a fireplace company or a certified chimney sweep for expert installation and maintenance of this situation.

    You are literally playing with fire. Use an expert.

    And as far as the type of manufactured chimney is concerned, there is a less expensive manufactured chimney system that is use on gas only. The system is called "B vent". It is usually a galvanized outer pipe with an aluminum inner pipe. it must be kept 2" from combustable material so there are supports that accommodate that minimum clearance. The inner temperature must not exceed 1200°. Since gas flame is lower in temperature that oil, coal and wood fires the less expensive B vent is OK for gas appliances.

    If you need a manufactured chimney that can accommodate oil heat appliances, you must use "Class A" manufactured chimney systems. These are also known as All Fuel Chimneys. An oil flame can reach temperatures exceeding 2000°, and if that oil starts to burn inside the a B-vent chimney system, it will melt like a Hershey bar on the rear window shelf of a '58 Buick in Florida during August. There are some Class A systems that have a galvanized outer pipe with a middle galvanized pipe and an inner stainless steel liner. These are called triple wall pipes. These have a much larger overall dimension or circumference. There is at least one other other brand that has a stainless steel outer pipe and a stainless steel inner pipe. The space between the pipes is filled with a powered masonry product. The pipe brand is Metalbestos. In the past it was asbestos powder filled, but asbestos is no longer used. This is the All Fuel chimney system I preferred because of its smaller diameter and the long lasting Stainless Steel outer pipe. Looks nicer for many, many years. and does not need that fake metal box with bricks painted on the outside.

    You need to read the manufacturers instructions for the brand and type system you have in place, to determine if you have "B vent" or "All Fuel" chimney system. There should be a label on each piece of pipe in the system.

    And what @STEVEusaPA said "don't use a roofer for chimney advise". You are lucky if they know how to keep a roof from leaking!

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    rbd33
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,060
    edited August 2022
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    This looks like a picture I used in my OIL HEAT training class.

    The picture I used had an exterior masonry chimney on a ranch home (1 story) that had a pine tree growing next to it. The first picture was from when we first moved in in 1963 and there was no pine tree. In 2002 there was a pine tree that had grown at least 10+ feet over the chimney top.

    And I would pose a question "Why did this chimney work just fine for over 30 years, and all of a sudden they have nothing but sooting problems every year since 1998?" The answer is the 25 year old pine tree is causing a downdraft when the wind blows from the northeast. That tree is now an air scoop forcing the pressure down the chimney and the oil burner gets choked of air since the exhaust can't get out.

    I think you have troubles other than just the new pieces of manufactured chimney. But I would need to see more of the tree and the chimney and the roof line and how they all relate to each other.

    Mr. Ed.

    @Bob Harper would agree with needing more pictures too


    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • rbd33
    rbd33 Member Posts: 14
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    This sounds suspiciously like a Question that I recently answered this way
    The "Dirt" that you are talking about... What did it consist of? That would help pinpoint the source. If the dirt was leaves, that would have a different source that if it were mostly carbon (SOOT). What you are describing sounds like a Class A manufactured chimney. A liner would be a single wall metal pipe that is inserted in a masonry chimney. Sometimes the terracotta sections of the inside of a masonry chimney are referred to as a liner. This might be what you are referring to: http://www.csiworldwide.com/AirJet/All-Fuel Chimney.htm. These manufactured chimneys come with detailed installation instructions in order to make them safe and weather proof. A roofer may not be the best person to install a chimney. You may want to contact a fireplace company or a certified chimney sweep for expert installation and maintenance of this situation. You are literally playing with fire. Use an expert.
    And as far as the type of manufactured chimney is concerned, there is a less expensive manufactured chimney system that is use on gas only. The system is called "B vent". It is usually a galvanized outer pipe with an aluminum inner pipe. it must be kept 2" from combustable material so there are supports that accommodate that minimum clearance. The inner temperature must not exceed 1200°. Since gas flame is lower in temperature that oil, coal and wood fires the less expensive B vent is OK for gas appliances. If you need a manufactured chimney that can accommodate oil heat appliances, you must use "Class A" manufactured chimney systems. These are also known as All Fuel Chimneys. An oil flame can reach temperatures exceeding 2000°, and if that oil starts to burn inside the a B-vent chimney system, it will melt like a Hershey bar on the rear window shelf of a '58 Buick in Florida during August. There are some Class A systems that have a galvanized outer pipe with a middle galvanized pipe and an inner stainless steel liner. These are called triple wall pipes. These have a much larger overall dimension or circumference. There is at least one other other brand that has a stainless steel outer pipe and a stainless steel inner pipe. The space between the pipes is filled with a powered masonry product. The pipe brand is Metalbestos. In the past it was asbestos powder filled, but asbestos is no longer used. This is the All Fuel chimney system I preferred because of its smaller diameter and the long lasting Stainless Steel outer pipe. Looks nicer for many, many years. and does not need that fake metal box with bricks painted on the outside. You need to read the manufacturers instructions for the brand and type system you have in place, to determine if you have "B vent" or "All Fuel" chimney system. There should be a label on each piece of pipe in the system. And what @STEVEusaPA said "don't use a roofer for chimney advise". You are lucky if they know how to keep a roof from leaking!
    Thank you for the reply. I did post another question asking about the source of dirt at the base of the chimney liner. As I stated, I had a prefab metal housing with cap as shown in the pic. It wasn’t a masonry chimney. I also had an air-cooled chimney liner (3 pipes) no insulation.    Interesting about the tree.  I now have a new Peerless WBV-3 boilerxand Selkirk Ultra-Temp Stainless Steel chimney. 
    I have no clue how all the dirt accumulated around the base.  And as for the old housing. The chimney liner was for oil but when I look up the air jet chimney housing it says for B vent. In a couple of stores it will say for all fuels but it looks exactly the same as the B vent kit. I have no clue if the housing makes a difference if the chimney liner is the correct one for the fuel type but the person who installed the new chimney told me that I should have had a different cap. That the one pictured was “low vent” and I needed a high vent cap. 
  • rbd33
    rbd33 Member Posts: 14
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    This is the new chimney before the supports were added. It is taller than the old one. It is a Selkirk Ultra-temp  
  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
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    You're going to have to go up there and re-goo that flashing every year. Should look more like the sewer vent.

    There was an error rendering this rich post.

    Bob Harper
  • Bob Harper
    Bob Harper Member Posts: 1,040
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    That roof flashing should be discarded and replaced. Any chimney or vent greater than 5' above the roof must have a roof brace.
    B-vent rated 550F max; L vent 570F; All fuel Class A chimney 2,100F. Class A chimneys use solid-packed low chloride formula ceramic fiber insulation. Typically, 2" clearance to combustibles but you can't assume. There are some class A pipes that are galvanized steel or galvalume outers while others still use a 400 series stainless steel outer. The inners are typically 316 or 444 ss. There is at least one triple walled pipe still in current production. It is a true thermosyphon but instead of the cold inner wall like the original x3, it has a blanket of ceramic fiber to maintain stack temps. to reduce creosote and condensation while maintaining a stronger draft pressure. We use it on certain EPA certified fireplace/ woodstove hybrids.
    STEVEusaPA
  • rbd33
    rbd33 Member Posts: 14
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    That roof flashing should be discarded and replaced. Any chimney or vent greater than 5' above the roof must have a roof brace. B-vent rated 550F max; L vent 570F; All fuel Class A chimney 2,100F. Class A chimneys use solid-packed low chloride formula ceramic fiber insulation. Typically, 2" clearance to combustibles but you can't assume. There are some class A pipes that are galvanized steel or galvalume outers while others still use a 400 series stainless steel outer. The inners are typically 316 or 444 ss. There is at least one triple walled pipe still in current production. It is a true thermosyphon but instead of the cold inner wall like the original x3, it has a blanket of ceramic fiber to maintain stack temps. to reduce creosote and condensation while maintaining a stronger draft pressure. We use it on certain EPA certified fireplace/ woodstove hybrids.
    There is a roof brace. The photo I posted was before the brace was added. This was just installed 2 weeks ago and the installer told me he did the best flashing-which for me was a big concern as I’ve had leaks in the past. What type of flashing should it have?  I have driven around my neighborhood and other people look like they have cement flashing. 
    This chimney is the Selkirk Ultra Temp : 
    • 304 Stainless Steel Inner Liner
    • 430 Stainless Steel Outer Wall
    • 1" Solid Pack Mineral Wool Insulation
    • All residential fuels
  • rbd33
    rbd33 Member Posts: 14
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    You're going to have to go up there and re-goo that flashing every year. Should look more like the sewer vent.
    Could you post a photo of what the flashing should look like? This was just done 2 weeks ago. I’m growing quite frustrated that I can’t trust any supposed professionals anymore. I had so many issues with chimneys in the past and this individual was told all past history. He told me he did his own flashing and it was the best. Considering the cost of this job I’m just disgusted. 
  • rbd33
    rbd33 Member Posts: 14
    Options

    You're going to have to go up there and re-goo that flashing every year. Should look more like the sewer vent.

    This is a question for the expert @Bob Harper.
    As a side note, I don't want chimney info from a roofer.</

    <blockquote class="UserQuote">

    You're going to have to go up there and re-goo that flashing every year. Should look more like the sewer vent.



    This is what is under the roof tar.
  • rbd33
    rbd33 Member Posts: 14
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    rbd33 said:



    That roof flashing should be discarded and replaced. Any chimney or vent greater than 5' above the roof must have a roof brace.
    B-vent rated 550F max; L vent 570F; All fuel Class A chimney 2,100F. Class A chimneys use solid-packed low chloride formula ceramic fiber insulation. Typically, 2" clearance to combustibles but you can't assume. There are some class A pipes that are galvanized steel or galvalume outers while others still use a 400 series stainless steel outer. The inners are typically 316 or 444 ss. There is at least one triple walled pipe still in current production. It is a true thermosyphon but instead of the cold inner wall like the original x3, it has a blanket of ceramic fiber to maintain stack temps. to reduce creosote and condensation while maintaining a stronger draft pressure. We use it on certain EPA certified fireplace/ woodstove hybrids.

    There is a roof brace. The photo I posted was before the brace was added. This was just installed 2 weeks ago and the installer told me he did the best flashing-which for me was a big concern as I’ve had leaks in the past. What type of flashing should it have?  I have driven around my neighborhood and other people look like they have cement flashing. 
    This chimney is the Selkirk Ultra Temp : 
    • 304 Stainless Steel Inner Liner
    • 430 Stainless Steel Outer Wall
    • 1" Solid Pack Mineral Wool Insulation
    • All residential fuels

    This is what is under the roofing tar.

  • rbd33
    rbd33 Member Posts: 14
    Options

    That roof flashing should be discarded and replaced. Any chimney or vent greater than 5' above the roof must have a roof brace.
    B-vent rated 550F max; L vent 570F; All fuel Class A chimney 2,100F. Class A chimneys use solid-packed low chloride formula ceramic fiber insulation. Typically, 2" clearance to combustibles but you can't assume. There are some class A pipes that are galvanized steel or galvalume outers while others still use a 400 series stainless steel outer. The inners are typically 316 or 444 ss. There is at least one triple walled pipe still in current production. It is a true thermosyphon but instead of the cold inner wall like the original x3, it has a blanket of ceramic fiber to maintain stack temps. to reduce creosote and condensation while maintaining a stronger draft pressure. We use it on certain EPA certified fireplace/ woodstove hybrids.

    That roof flashing should be discarded and replaced. Any chimney or vent greater than 5' above the roof must have a roof brace.
    B-vent rated 550F max; L vent 570F; All fuel Class A chimney 2,100F. Class A chimneys use solid-packed low chloride formula ceramic fiber insulation. Typically, 2" clearance to combustibles but you can't assume. There are some class A pipes that are galvanized steel or galvalume outers while others still use a 400 series stainless steel outer. The inners are typically 316 or 444 ss. There is at least one triple walled pipe still in current production. It is a true thermosyphon but instead of the cold inner wall like the original x3, it has a blanket of ceramic fiber to maintain stack temps. to reduce creosote and condensation while maintaining a stronger draft pressure. We use it on certain EPA certified fireplace/ woodstove hybrids.


    This is w
    This is under the roofing tar

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,060
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    That appears to be the flashing that is recommended by Selkirk that is designed by the manufacturer and therefore is the correct flashing. the fact the the installer used lots of roof cement does not void the fact the you (he) used the correct flashing.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,060
    edited August 2022
    Options
    I am trying to understand your concern.

    I have crossed out any reference to the old because it only confuses your question.
    rbd33 said:

    I just had the chimney for my oil boiler replaced. Previously I had a 3 layer air cooled galvanized metal chimney that was covered by a prefab metal housing made to look like bricks with a chimney cap. It was replaced by a Selkirk Ultra Temp Stainless Steel Chimney. There was a lot of soot in the old chimney liner and the outer layer was rusted with some corrosion and holes. The chimney person told me that I had had the wrong kind of cap, that it was low vent and made for gas and it should have been swapped for a high vent cap for the right draft for oil. (WAS THIS REGARDING THE OLD CHIMNEY OR THE SELKIRK ULTRA?) Is this a thing? I called the roofing company that installed the old cap and he told me chimney people lie because they want you to get a new chimney and that they’ve installed thousands of these and no one has ever complained of problems. (WAS THIS REFERRING TO THE OLD OR THE SELKIRK?) I replied that people don’t complain because they don’t know. They don’t necessarily know if their boiler is working harder, or dirtier and if a chimney cap could be a contributing factor. He also said he consulted chimney people who confirmed that their chimney caps were just fine. I guess the chimney people he consulted were not among the ones who lie. In any case are there caps that should be used for gas that should NOT be used for oil? And why?

    So I am wondering if you have a problem with Soot since your new chimney was installed? Is that your question?

    What I see in your photograph is that cap and the flashing are the ones that are made by SELKIRK for that particular model of manufactured chimney. As long as all the pieces are from the same system, you should have no problems.

    Regarding the TREE thing. Field Controls is a company that makes venting equipment for heating systems. they publish this Contractor Guide https://www.sidharvey.com/documents/UNI-02374_Broc.pdf
    On page 35 they speak of Draft Inducers. This device is used to solve Down-Draft problems. There is brief description of what may cause a down draft on that page. That is not a comprehensive list or detailed explanation of all causes. But the tree one is in there.

    If your trees are a lot higher than your chimney, That may be a source of your soot problem. No design chimney will be able to overcome mother nature. If you keep the tree, then you will need to build your chimney higher than the tree. If you trim the tree, then you need to keep doing that every few years. Unless the tree stops growing for some reason.

    If you do not have any problems with Soot now, since the new chimney system has been installed, then there is nothing to be concerned about.

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

  • Bob Harper
    Bob Harper Member Posts: 1,040
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    If you look at any other roof flashing, such as for DWV pipes, you will see the upper half is tucked up under the shingles with the lower 1/2 to 1/3 exposed on top of the shingles. This allows proper water shedding without making it look like a character from a sci-fi movie mucked with combustible plastic roof cement. If they did this mess, did they cut a large enough hole in the roof decking to maintain your 2" clearance to combustibles?
  • rbd33
    rbd33 Member Posts: 14
    Options
    I am trying to understand your concern. I have crossed out any reference to the old because it only confuses your question.
    I just had the chimney for my oil boiler replaced. Previously I had a 3 layer air cooled galvanized metal chimney that was covered by a prefab metal housing made to look like bricks with a chimney cap. It was replaced by a Selkirk Ultra Temp Stainless Steel Chimney. There was a lot of soot in the old chimney liner and the outer layer was rusted with some corrosion and holes. The chimney person told me that I had had the wrong kind of cap, that it was low vent and made for gas and it should have been swapped for a high vent cap for the right draft for oil. (WAS THIS REGARDING THE OLD CHIMNEY OR THE SELKIRK ULTRA?) Is this a thing? I called the roofing company that installed the old cap and he told me chimney people lie because they want you to get a new chimney and that they’ve installed thousands of these and no one has ever complained of problems. (WAS THIS REFERRING TO THE OLD OR THE SELKIRK?) I replied that people don’t complain because they don’t know. They don’t necessarily know if their boiler is working harder, or dirtier and if a chimney cap could be a contributing factor. He also said he consulted chimney people who confirmed that their chimney caps were just fine. I guess the chimney people he consulted were not among the ones who lie. In any case are there caps that should be used for gas that should NOT be used for oil? And why?
    So I am wondering if you have a problem with Soot since your new chimney was installed? Is that your question? What I see in your photograph is that cap and the flashing are the ones that are made by SELKIRK for that particular model of manufactured chimney. As long as all the pieces are from the same system, you should have no problems. Regarding the TREE thing. Field Controls is a company that makes venting equipment for heating systems. they publish this Contractor Guide https://www.sidharvey.com/documents/UNI-02374_Broc.pdf On page 35 they speak of Draft Inducers. This device is used to solve Down-Draft problems. There is brief description of what may cause a down draft on that page. That is not a comprehensive list or detailed explanation of all causes. But the tree one is in there. If your trees are a lot higher than your chimney, That may be a source of your soot problem. No design chimney will be able to overcome mother nature. If you keep the tree, then you will need to build your chimney higher than the tree. If you trim the tree, then you need to keep doing that every few years. Unless the tree stops growing for some reason. If you do not have any problems with Soot now, since the new chimney system has been installed, then there is nothing to be concerned about.
    My questions about the chimney cap and soot had to do with the old chimney, the one with the fake brick metal housing. The chimney person told me it was the wrong chimnet cap and therefore caused my burner to work harder and have more soot. The roofer who installed that cap told me he’s done thousands of these and never had a complaint so it can’t be wrong. 
  • rbd33
    rbd33 Member Posts: 14
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    If you look at any other roof flashing, such as for DWV pipes, you will see the upper half is tucked up under the shingles with the lower 1/2 to 1/3 exposed on top of the shingles. This allows proper water shedding without making it look like a character from a sci-fi movie mucked with combustible plastic roof cement. If they did this mess, did they cut a large enough hole in the roof decking to maintain your 2" clearance to combustibles?
    They did not cut a hole in the roof decking. There was a square opening from the previous chimney. If you zoom in on the photo I posted you will see that there is sort of a square depression surrounding the chimney pipe. This is the old opening. Unfortunately I don’t have a photo before the new chimney pipe was placed. I just recall that there was a framed out square opening. The shingles on the roof were placed for the former square metal chimney housing. They didn’t add and shingles. So now that you have explained how it should be done I’m thinking that the top part of the flashing may not have been slid under the shingles or at least not very much under and maybe this is why the excessive amount of tar. 
  • EdTheHeaterMan
    EdTheHeaterMan Member Posts: 8,060
    Options
    rbd33 said:


    My questions about the chimney cap and soot had to do with the old chimney, the one with the fake brick metal housing. The chimney person told me it was the wrong chimnet cap and therefore caused my burner to work harder and have more soot. The roofer who installed that cap told me he’s done thousands of these and never had a complaint so it can’t be wrong. 

    So you have no issue since your new Selkirk manufactured chimney has been installed. Have you had an oil heat technician do a combustion test on the oil burner since the new Selkirk chimney system was installed? I would highly recommend that!

    Mr. Ed

    Edward Young Retired

    After you make that expensive repair and you still have the same problem, What will you check next?

    rbd33