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sooted up gas boiler

Paul_69
Paul_69 Member Posts: 251
what are causes of gas boilers plugging up with black carbon soot. good flame and proper gas pressure. boiler room is tight with 2 boilers 75000 and 100,000 btu atmosheric boilers and 2 gas 40 gallon water heaters.has one 4 inch round vent from out side only and a grill on boiler room door going to a area that is tight and no air infiltration and tightly construced.they just replaced a boiler that was red tagged for being plugged with soot and a company installed a new boiler and this one was plugged with soot 3 weeks later. i dont think its both boilers and i dont feel it has eneough combustion air so i called the inspector and there wasnt a permit pulled it looks like and they are coming out to look it over and i didnt want to have problems so i told homeowner to get this done and get installer back as well.also has 5 inch flue liner on 2 story house and wondered if this was able to handle load as well. but i cant believe that this would be proper air for code and if isnt is there something else causing the soot up and there is something else going on that i dont see that would cause this to happen to 2 boilers 3 weeks apart. wow i seem to get alot of other companys messes.

Comments

  • icesailor
    icesailor Member Posts: 7,265
    Soot Mess:

    Good for you to be astute enough to recognize a lack of combustion make-up air.

    A pox on the hackaroos that don't have the inquiring mind to figure out why the first boiler sooted up in the first place. Those companies are some of the ones that we who have invested time in education and money in equipment to do a proper diagnosis, don't get the work.

    Say what you may about Massachusetts. But any and all licensed plumbers, gas fitters and LP installers are taught from the beginning, and reminded in our annual CE classes, make up air is important. And so is a chimney inspection when installing new equipment.

    Every time a consumer gets worked over by a Hackaroo, it reflects on all of us and costs us too. In new and foolish regulations that never bother the Hackaroos, but just us.

    Also, in Massachusetts, if you do a new Install of ANY gas equipment, you must to have a CO detector installed for compliance. No CO, no pass inspection. Had there been a CO detector where that equipment is, the chirping of nasty birds would have been overwhelming.

    Do you carry a personal CO detector with you? You should. If you are smart enough to recognize that there was a make-up issue, you should know that there is almost always CO around bad running equipment. You could pass out and die before you realize you are in trouble. If you do service, and you run into direct vented equipment, and you hear it running, stick the instrument into the exhaust. It will give you a very quick way to judge how it is running, Twice, I have had the instrument lock up at over 1200 PPM. Then, you will want a digital combustion analyzer.
  • Tim McElwain
    Tim McElwain Member Posts: 4,482
    Paul by my calculations

    you have a total of roughly 255,000 BTU's which would require a space 40 feet by 40 feet by 8 foot high to handle that equipment using the air from within the space. If the room is not that size and is smaller then it is a confined space and will need air from outdoors using two openings one 12 inches from the ceiling the other 12 inches from the floor, these will provide "air for combustion" that is not "make up air". "Make up air" is air required to replace air removed by mechanical exhausting and is totally removed from the additional air required as air for combustion. It does not take very long for a unit to soot up if there is insufficient air in the combustion zone. The openings would have to sized according to codes in your area such as NFPA 54 National Fuel Gas Code or International Fuel Gas Code.



    You need to get a good course on codes which if properly done will cover air for combustion and venting. I know of very few places that teach those subjects correctly so you really have to shop around.
  • Paul_69
    Paul_69 Member Posts: 251
    soot

    thanks tim for your info and help. i am a heating tech. not a plumber so i dont get into many gas installs unless i have my plumber with me. i can work on gas boilers and furnaces but cant do venting or gas fitting i was told but can service units in mass.so i saw this mess i told you about and was confident it was lacking combustion air. can i still take classes on venting even though i am not a gas fitter or plumber? but what really got me on these two boilers plugging up is the room doesnt look like it has changed and had all these appliances for 15 to 20 years. hoe did it get by all these years? or have they had trouble and not tell the truth, thats what gets me really baffled. i see the 4 inch vent and say not eneough and customer says its always been like this and didnt soot up until now!! thanks alot....            paul
  • Tim McElwain
    Tim McElwain Member Posts: 4,482
    You need to understand

    air for combustion, venting and everything about installing equipment in order to be able to properly service the equipment. You need to come to my classes in Warren, RI and get some training.



    There could be something else wrong here causing the sooting so it needs further investigation. I hope this equipment is now shut off and not operating as soot is an indication of carbon monoxide and it is very dangerous. It needs a chimney inspection, along with a check for depressurization of the combustion zone caused by mechanical exhausting in the building. The fact that the same thing happened with new equipment tells me the equipment is not the problem but either air or venting or something that has changed in this building recently.
  • Paul_69
    Paul_69 Member Posts: 251
    ok

    i will take you up on the classes. i shut unit off and homeowner called gas co. and they put it back on and told him there was enough combustion air and good draft and i dont buy it at all.i went further after i shut it off and called plumbing inspector and told him that this job was never inspected and he was going to investigate this job. a contractor for sears put this in. i may need to learn more about everything you mentioned and may not know what else is going on but i was very concerned and i feel i did what was right tim.i think the chimney might be wrong there also. so i will say it to you this way if the contractor who installed did what was right and pulled inspection then things would have been brought up to code and would be safe. i saw a few things here that are more than likely wrong and not up to code and furthermore saw there was NO INSPECTION PULLED.i called the inspector and sears and let them know what i saw and what i did. i will call these people after and find out what became of this job.i may need some more knowledge with this area of venting and air etc.but i really am trying to do whats right.on a new boiler it should have been inspected and up to code before i got involved servicing it.
  • Jean-David Beyer
    Jean-David Beyer Member Posts: 2,666
    Air for combustion.

    Since I am not a professional, I do not need to know the codes because the contractors I hire are supposed to know them, and comply with them, and the inspectors surely should know them.



    Now I know the code says that if you do not have a supply of outside air piped to a furnace or boiler, you need a room volume of such and such per BTU/hour, If not, you need two vents, one within a foot from the ceiling, and another within a foot from the floor. The sizes are specified.



    But let us say I have a house of the right volume to not need vents, but being an infiltration nut, I have the house so well sealed that nowhere near enough air leaks in. I might comply with the code, but still be establishing dangerous conditions. Perhaps there is more to the code than I think (I never read a code on ventilation), and it says that even if you comply with everything else, if a vacuum of such and such or more exists it requires MORE ventilation. I would not know, but I sure hope so. So one should have a suitable vacuum gauge or water manometer to measure the vacuum near the boiler or furnace or hot water heater or whatever to make sure there is enough combustion air available.
  • Tim McElwain
    Tim McElwain Member Posts: 4,482
    Inspection or not

    you are liable for the safety of the customer. A combustion analysis should have been done once the cleaning was accomplished. If it is unsafe it should be made inoperative. You do not need the gas company, inspector or anyone else to do that. God forbid something goes wrong everyone will bail out and the last person there is the fall guy. Made inoperative means disconnecting the gas or oil supply to equipment and capping of the fuel lines. It is the only acceptable solution the courts will recognize. Shutting off switches or gas valves is not sufficient.
  • Tim McElwain
    Tim McElwain Member Posts: 4,482
    edited February 2012
    The Weil-McLain UItra

    I assume is getting its air from outdoors so combustion and ventilation air is not an issue.



    To answer your inquiry the actual need for air other than space size has to do with "Air Changes Per Hour" (ACH) it must be more than 0.40 ACH or air is required even for health reasons as the air becomes stagnant. A fan in the can or HRV or ERV could provide air in that case.  The fuel gas code contains charts which have been calculated at different levels of air change. In some jurisdictions an ACH is required to be provided by the home or commercial builder.



    The answer to how you know if you have sufficient air is to do a combustion analysis and the figures you come up with will tell you if you have enough air or not.
  • icesailor
    icesailor Member Posts: 7,265
    Caring(Giving A Rats Red Rectum)

    You sound like you give a $&^%. If you are self employed, buy a digital combustion analysis. It will help out a lot. What you found takes an astute observer. Most would be in and out in a flash. You can't take for granted that someone behind you will do what they should do and fix something. Many are absolutely clueless about codes, requirements and how modern (let alone the old stuff) equipment works.

    I know what you are trying to do. I have worked for years trying to figure out a reasonable and effective way to check for proper make-up air. I haven't found it yet. So, if there isn't an easy way to figure it out, the ones who have had the responsibility passed to, will say they can't find anything wrong.

    It is my understanding that Digital Combustion Analysis print-outs are almost legal documents showing that something is or isn't working properly when you did the test and left. That's a big reason I bought mine. An oil company I work with requires that every employee do a CA on every piece of equipment they touch. Their insurance company requires saved results. No test, soot up, no coverage.

    I download my results to my Laptop.
  • Paul_69
    Paul_69 Member Posts: 251
    ca

    thx ice, ido really try to do whats right and not turn my head. i am self employed and it sounds like the digital anaylizer is a must. does it have to have print out?
  • Jim Davis_3
    Jim Davis_3 Member Posts: 578
    combustion air

    A draft test is the verification of combustion air in many cases.  If the draft in the flue is -.02" or higher you have plenty of combustion air in the room.  However that does not verify if you have any combustion air at the burner.  That can only be determined by a combustion analyzer.
  • Nat
    Nat Member Posts: 8
    Why?

    After catching up on this thread, I can't help but ask why anyone in this trade would "replace" atmospheric vented boilers with another atmospheric vented boiler in the year 2012..??  This installation should have one or 2 indirect water heaters and one of many available, very efficient, properly installed and sized modulating boiler. There's your make up air problem and crazy venting solved for good. This isn't going green, it's common sense... The future is already here..
  • Steamhead
    Steamhead Member Posts: 14,863
    Chimney-vented boilers have their place

    we find in many older homes and other buildings, there really is not a good place to vent a mod-con, unless the owner is willing to make major modifications to the building. And very few people are willing to pay for that, especially in this poor economy. 



    But there is a better chimney-vented alternative to the usual atmospheric boiler- a cast-iron wet-base boiler with a power burner. We have had much success with the Solaia boilers on hot-water. These could be had with HeatWise power gas burners, until HeatWise went under- now they're using the Carlin EZ-Gas units.
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • Steamhead
    Steamhead Member Posts: 14,863
    YYYYYYeeeesssssssssss!!!!!!!!!!!!!!!!!!!!!

    An analyzer is a must! There is no way to properly set up a burner without one. Period.



    But you also need the know-how to use it properly. Get in touch with Tim and get to his classes. I did, and got a LOT out of it.
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • Tim McElwain
    Tim McElwain Member Posts: 4,482
    edited February 2012
    It may just be the

    case that Mod/Con residential boilers may be the downfall of Hydronics. When you make it complicated it will eventually come back to haunt you. I have been doing this boiler thing and warm air for over 50 years and I find that when it gets complicated and needs a lot of attention and service it slowly disappears. You find the units sitting at curb side waiting for the junk man. I have a background in electronics along with many years in the gas industry and in the control development side of the business. I really need to sit down and study very carefully the I and O manuals on these units along with a factory school or at least have their rep come do a class at my training center. That is so I can understand and discuss these units with some degree of understanding. Follow the postings here on problems and questions on these units as to how to correctly install them and then who will service them is the next question. I have tried to simplify the troubleshooting side with three volumes on Mod/Con and am working on number 4 and 5 as we post here.





    It has been discussed on LinkedIn as to making things simple so everyone can understand and get on board with installing these units.They are not a large part of the sales on just Hydronic boilers and boilers are already a small percentage across the country of total sales on heating equipment.





    All of that and as Steamhead stated the cost is prohibitive to many. I am in RI with several cities on the verge of bankruptcy and one of the highest unemployment rates in the country. Try selling one of those units here it will be a hard sale.
  • icesailor
    icesailor Member Posts: 7,265
    Complications:

    How right you are, how right you are.

    I have a 6 year old building with a concrete block and tile chimney that has a 30 gallon gas tank type heater. It isn't big enough. I can't use a wall hung heater in this lined chimney but I could install a bigger tank. but wants the higher output of a bigger heater.  Explain that to the owner.

    I find that when someone thinks they want one of these high efficient hydronic systems, you give a customer a price, and they go Warm Air.
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