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Here we explain the inspection and adjustment of draft regulators or barometric dampers on oil fired heating equipment: A Guide to Barometric Dampers on Oil Fired Boilers, Furnaces, Water Heaters: inspection, adjustment, cleaning, troubleshooting.

This website answers most questions about central heating system troubleshooting, inspection, diagnosis, and repairs. We describe how to inspect residential heating systems to inform home owners, buyers, and home inspectors of common heating system defects.

The articles at this website describe the basic components of a home heating system, how to find the rated heating capacity of an heating system by examining various data tags and components, how to recognize common heating system operating or safety defects, and how to save money on home heating costs. We include product safety recall and other heating system hazards.

© Copyright 2012 InspectAPedia.com, All Rights Reserved. Information Accuracy & Bias Pledge is at below-left. Use page top links to major topics or use links at the left of each page to navigate within topics and documents at this website. Green links show where you are in a document series or at this website.

Guide to Inspecting Barometric Dampers or Draft Regulators on Oil Fired Heaters, Furnaces, Boilers, Water Heaters

Details about draft control on oil fired heating systems (such as the oil fired heater shown in the photo above), including furnaces or boilers, are discussed right here at Draft Regulators barometric dampers on oil fired equipment. (Details about draft control for gas fired heating systems, including furnaces or boilers, are discussed at Furnace Draft Hood on gas fired equipment. Readers should also see CHIMNEY INSPECTION & REPAIR GUIDE and Flue Vent Connectors - Boilers, Furnaces for inspection, defect identification, and repair suggestions for chimneys and flues. Contact us to suggest text changes and additions and, if you wish, to receive online listing and credit for that contribution.

Barometric dampers are devices used to regulate the draft on oil-fired heating equipment such as furnaces, boilers, or water heaters. The barometric damper or draft regulating device we are discussing here is normally used only on oil-fired heating equipment, not on gas-fired equipment. The equivalent draft control on gas fired heating systems is discussed at Furnace Draft Hood on gas fired equipment. On oil fired equipment the barometric damper, or draft regulator is typically a round Tee inserted in the flue vent connector between the heating appliance and the chimney. The face of the tee contains a round "door" with an adjustable weight. The service technician adjusts the weight to control the swing or opening of this door which in turn controls the amount of excess air that can enter the flue and chimney when the oil burner is operating. The draft regulator in our photo is not working - and has been deliberately jammed - indicating that something else is wrong, probably a chimney problem or an oil burner operating problem: the technician was unable to get enough draft, so s/he defeated the regulator - this is not a good idea, as we'll explain below. For a detailed guide to inspecting draft regulators and barometric dampers please see How to Inspect a Barometric Damper.

Why we need the Barometric Damper or Draft Regulator on a Boiler or Furnace

During oil burner operation, and also on some gas fired equipment, combustion air moves into the burner are and combustion chamber (as combustion air). As combustion continues (the fuel is mixed with air and burned), a mix of air and combustion gases continues onwards, moving out of the combustion chamber, up through the boiler or furnace heat exchanger, through the flue vent connector ("stack pipe or flue pipe" and on into the chimney where these gases are finally vented outside, usually above the building roof.

The force with which this air or combustion gas moves is the "draft" inside of the heating appliance.

Too much draft increases heating appliance operating cost by venting heat out through the chimney instead of transferring the heat into the building where it was wanted. Too much draft can also increase chimney temperatures to an unsafe level.

Too little draft can result in incomplete combustion, soot-clogging of heating equipment (dangerous), and more dangerous heating appliance malfunctions such as oil burner puffbacks and in some cases dangerous production of carbon monoxide gas that leaks into the building (a potentially fatal problem).

So virtually all fossil-fuel-fired heating appliances provide some sort of draft control or draft regulator to keep the draft at required levels both in the combustion chamber and out through the chimney.

Details of Why is a draft regulator is needed ?

Chimney draft is not constant. While above we described how we measure draft inside of heating equipment and on the way to the chimney where (we hope) combustion gases are to be vented safely outside, the "draft" that the oil burner and furnace or boiler experience are not constant.

For example wind blowing over a chimney top can increase draft, as can a second appliance using the same chimney as the heater. Since the force of draft is not normally constant, and since we want the draft to be constant for optimum oil burner operation, the barometric damper is installed.

If the oil burner sees flue draft that is too low the combustion gases will not vent safely out of the building and the heating equipment may suffer from backpressure in the combustion chamber, causing overheating or other malfunctions. Also see OIL BURNERS and OIL BURNER NOISE SMOKE ODORS

Our photo (above left) shows a chimney that extends less than two feet above a flat roof on a one story home, resulting in inadequate draft and sooty burner operation. The home suffered recurrent oil burner sooting, puffbacks, high and repeated heating service repair bills, and ineffective attempts by heating service techs to "fix" the problem by running the oil burner at high temperatures - a trick that mostly served to increase the heating bills for the home.

If you have this problem see Chimney Too Short and Chimney Height Extensions as well as Draft Inducer Fans. At DRAFT MEASUREMENT, CHIMNEYS & FLUES we illustrate how this particular short chimney and inadequate draft problem were finally fixed.

If the oil burner sees flue draft that is too high combustion gases will vent out of the building just fine, but we're sending too much heat up the chimney by moving combustion gases too fast through the heater, thus we're sending our oil dollars up the chimney as heat rather than into the building as heat.

The service technician adjusts the barometric damper to maintain a continuous draft in the range we described above. Then if local conditions change, the barometric damper can open or close to let in more or less additional air into the flue and chimney, keeping the draft constant.

Are Barometric Draft Controls Used on Gas-Fired Equipment?

Incidentally, draft controls might be found on gas-fired heating equipment too, but the specifications are quite different. Gas fired heaters such as domestic gas fired furnaces are usually designed to operate at very low over-fire drafts - which means almost zero draft will be measured at the flue vent connections. That's why you usually don't see a hinged-door barometric draft regulator on gas fired equipment. Take a look at DRAFT HOODS - gas fired for details.

Field Corporation [1], and Tjernlund [2] draft regulator producers, provides different model draft controls for gas fired equipment, such as the Field Type MG1 and MG + MG2 regulators which use double swinging gates that open inward under normal up-draft conditions and outward in case of blocked flues, thus relieving internal pressures. Since improper venting of gas fired appliances easily produces very dangerous, potentially fatal Carbon Monoxide (CO), it is critical that these appliances are vented properly.

Do not ever install an oil-fired appliance draft regulator such as the Field Type AF shown here onto gas-fired equipment.

Where Should the Draft Regulator (Barometric Damper) be Installed?

Barometric damper location: a barometric damper will work properly to regulate draft and reduce backdrafts in a variety of locations in relation to the heating appliance and the chimney. [Images at left are courtesy Field Controls.] Field corporation and other equipment manufacturers provide an instruction sheet with their product, showing the appropriate locations for a draft regulator. According to Field, "The control should be located as close as possible to a furnace or boiler and positioned as shown in [the figure at left]. The draft regulator should be 18" from a stack switch and at least 18" from a combustible ceiling or wall. Do not locate the draft regulator in a room separated from the appliance." [1] If the draft regulator is not located properly it won't work properly and the heating system may also be unsafe. Further, if you see a draft regulator installed at the far end of a very long flue vent connector, say 12 to 25 feet or more, there is a more basic problem with excessive flue length and operating problems related to that condition, independent of the draft regulator. See FLUE VENT CONNECTORS for details. "The barometric damper should be adjusted (by adjusting the weight position) to maintain as low a draft as will give good combustion and meet the requirements for heat. The bracket is marked "Lo", "Med" and "Hi" which correspond to draft settings [if draft is measured inside the flue immediately before the regulator] of 0.2", 0.4", and 0.6" w.c."

Measure Chimney & Flue Draft when adjusting the barometric damper / draft regulator

Details are at DRAFT MEASUREMENT, CHIMNEYS & FLUES. Excerpts are just below.

Normally we measure draft at two locations: over the fire or in the combustion chamber. The draft we typically see on oil fired heating equipment like water heaters, boilers and heating furnaces is - 0.02" to 0.03" water column (w.c.) in the combustion chamber just over the fire - 0.04" to 0.06" w.c. in the breech - the flue pipe area between the top of the boiler and the bottom of the barometric damper. Some oil burner models require higher draft than these numbers, and other oil burner models are actually tolerant of back-pressure in the combustion chamber (positive draft, or draft in the "wrong" direction"). The sketch at left showing a barometric damper on oil fired heating equipment (heating boilers or water heaters) was provided courtesy of Carson Dunlop. In the breech we want to see about -0.05 inches WC pressure. If the breech draft is too low the combustion process and venting process may be inadequate, and if the draft measured in the breech is lower than the draft measured over the fire, the oil burner and combustion chamber are operating under pressure - which is often a problem on residential heating systems since few of them are designed to work this way. Thanks to L. - for correcting our WC pressure data.

How Does a Barometric Draft Control or Draft Regulator Work?

It's easy to understand how a draft regulator work: as Carson Dunlop's sketch above shows. The service technician measures draft over the fire and in the breech, and she moves a little weight on the hinged barometric damper door to cause the door to open wider or less wide to let more or less room air into the chimney as needed.

As long as the gas pressure inside of the flue and chimney is less than room air (that is, it's "negative" as we explained below), air from the room wants to enter the chimney through the barometric damper opening. Like the porridge in Goldilocks and the Three Bears, there are three possibilities:

The draft as sensed at the barometric damper is too strong (maybe a wind is blowing over the chimney top, increasing the draft): in this case the draft inside the flue, at the breech at the draft regulator is more negative - maybe -1.2 " w.c.. Since the air in the room is at normal pressure it will be stronger than the pressure inside the flue, so air in the room will push the draft regulator door "in" and make it open, letting room air flow into the chimney until, balanced by the setting of the weight on the moving draft regulator's door, the incoming room air enters the flue in enough volume to drop the draft pressure back to its desired setting, maybe to -0.04" w.c.

The draft as sensed at the barometric damper is too weak (maybe a wind is blowing down the chimney flue because we left off our chimney cap): in this case the draft inside the flue, at the breech and thus at the draft regulator is less negative, maybe -0.01" w.c. than we wanted - we're having trouble sending those flue gases up the chimney. The little weight on the draft regulator door causes the door to close, reducing the inflow of room air into the flue, and thus increasing the draft in the flue back to the desired number, maybe to -0.04" w.c. once again.

The draft as sensed at the barometric damper is just right: it's hovering where we set it at -0.04" w.c. In this case the barometric draft regulator is probably showing its little door a little bit open, with a little room air flowing into the flue. (Otherwise we wouldn't have any room to close the door to increase the draft when we need to do so.) And the draft in the flue is staying at the desired number, maybe -0.04" w.c.

How is the Barometric Draft Control Adjusted? What are the recommended draft settings?

Weight location & adjustment on barometric draft controls

Weight location & adjustment on barometric draft controls: the weight that is adjusted to regulate the operation of the draft control needs to be properly located as well as adjusted. T he weight location switches on most regulators depending on whether the regulator is installed on a vertical flue or a horizontal flue. Field ships their draft regulators with the weight installed in position for a vertical flue. The adjustment weight is in the right-hand slot when you are facing the control. If the damper is to be installed on a horizontal flue, the weight must be removed from the right-hand slot and attached to the left hand slot as shown in the illustration and sketches above. Thanks to boiler expert Dirk Faegre for suggesting these additional details.

Why we Measure Carbon Dioxide CO₂ as Well as Draft when Adjusting the Draft Regulator

Field controls also points out that

It is essential that CO₂ readings be taken to determine proper [draft regulator] adjustments. (This test and others should be conducted by a qualified fuel oil dealer or appliance installer for your safety). [1]

While we and the draft regulator manufacturers give typical draft measurement numbers for draft over the fire and at the damper itself, some oil burner manufacturers may require specific draft settings other than those standard ones. In addition, variations in chimney and building details from one installation to another may affect how the oil burner, heating appliance itself, flue vent connector, chimney, chimney cap, and site wind conditions all interact. Ultimately we need to know these effects on combustion. We want not only proper draft and [usually] no backpressure in the combustion chamber, we also want efficient combustion - that's where the CO₂ measurement comes in.

List of Defects & Signs of trouble with a barometric damper or draft regulator and what they mean

For a detailed guide to inspecting draft regulators and barometric dampers please see How to Inspect a Barometric Damper.

No draft regulator or barometric damper is installed: in this case the heater may work but it is impossible to tune it for optimum performance. We may be wasting fuel and money. The barometric damper is shared: if the damper is connected so that it is shared by two different heaters, say an oil fired furnace and an oil fired water heater, it is impossible to tune the system for optimum performance since the two appliances will prefer different adjustments each. The barometric damper is broken or missing parts: it cannot do its job and needs repair or replacement. The barometric damper is stuck or has been wired shut or covered with foil or tape: we love this clue. This is what a service tech does when s/he simply has been unable to get adequate draft for the oil burner. The tech thinks that since draft is always inadequate on this system there is no reason to let any air in at the damper. Well that's true, but we're treating the symptom, not the cause. The root cause might be, for example, a blocked chimney flue - which is unsafe and needs to be discovered and cleared, or a chimney that is simply too short in its total height to ever develop adequate draft. We've also see this silly "repair" when the underlying problem leading to inadequate draft was that someone had left the cleanout door to the chimney open. The barometric damper is stuck in the "open" position - usually due to a mechanical defect that is easily repaired, but sometimes because the weight has been misadjusted or lost. An always-open damper cannot properly regulate draft. More draft regulator defects are described in detail at Questions & Answers about inspecting and adjusting the barometric damper and at How to Inspect a Barometric Damper we provide details about what you may see when inspecting the draft regulator or the flue that it serves.

Frequently Asked Questions (FAQs) About Draft Regulators on Heating Equipment

What is the Significance of Soot production or soot blow-back stains at the Damper or Draft Regulator

Soot production or soot blow-back stains at the combustion chamber inspection port or burner mounting tube (or soot in general).

Regardless of whether the draft regulator is serving an oil fired heating boiler or an oil fired water heater, soot coming out of the barometric damper or out of the flue vent pipe, or the presence of soot and burn marks on the heater, or even noises: stumbling, rumbling, noisy oil burners, as well as odors, are examples of improper oil burner operation that need prompt service.

Our photo at above left shows an example of improper oil burner operation on an oil fired water heater: both systems show soot blow-out at the water heater's combustion chamber inspection port.

At above right, a different heating system appliance shows soot beginning to blow back out of the draft regulator itself. And notice the sloppy installation? The draft regulator was not installed level. The weight system does not work properly when the damper door is out of level.

Often these soot marks are a symptom of excessive pressure or "back pressure" inside the combustion chamber. Since this water heater is connected so closely to the chimney in a pretty new house, our first guess was that the water heater itself needed cleaning.

Oil fired appliance sooting problems can be caused by an oil fired water heater or heating boiler that is way past due for cleaning (soot blocks the exhaust flue), by a blocked chimney, by improper draft regulator adjustment, or other defects.

When the oil burner is not operating, should the damper door be closed?

I am fascinated by and appreciative for your publication "Guide to Barometric Dampers..." Many thanks for the complete explanations.

I am getting the run-a-round from the 'service' people from the service company; I'm not sure they know much more than I.

I have one question which I hope you will answer: when the oil burner is not operating, should the damper door be closed? Logic would suggest to me that it should be closed but I am terribly uninformed. - R.D.B.

Reply: Generally, yes, at rest, the damper door is shut. But here are some things that might make it open:

A competent onsite heating or chimney and flue inspection by an expert usually finds additional clues that help accurately diagnose a problem with the heating appliance or the flue and chimney that vent its combustion products.

That warning made, yes, in general, a properly adjusted and balanced barometric "flapper" door is in the vertical or closed position when the heating flue to which it is connected is not in use. If the door is open you may be wasting warm air and heat from the area around the heating boiler or water heater that the damper is serving. Field Controls puts it this way:

Always set the [barometric damper draft] control to maintain as low a draft as will give good combustion and meet the requirements for heat. [1]

Why? Because if you set the draft higher than necessary, you are wasting money, sending heat up the chimney instead of into the building (or if it's a water heater, into the hot water tank). We need enough draft that the oil burner does not blow soot back into the building, and so that combustion is efficient, but we do not want excessive draft.

Below we list reasons that your draft regulator door is staying open. If you check all of these out and find that the installation is correct, the equipment is all operating normally, but that chimney and wind conditions are keeping the draft regulator open (and heat is thus wasted from your home), a solution could be the installation of an automatic flue vent damper that opens before the oil burner turns on and closes automatically when the oil burner has turned off. [See our photo at left]. Watch out: Installing an automatic flue damper can reduce building heat loss through the flue but we do not want to see this "solution" installed before you have an accurate diagnosis of just why your flue damper door is hanging open. We discuss automatic vent dampers in detail at Automatic Vent Dampers where we explain how they work, how they save money, and what they look like.

Here are some things that might explain why the barometric damper is hanging open even when the heater is not running:

The heater is cooling down: If you are looking at the damper right after the oil burner has shut down, the heater is still hot and a mix of hot air and combustion gases are still zooming up the flue and chimney. If the draft effect of those rising gases is creating an updraft that is more than proper for optimum heater adjustment, the damper door will open to admit room air, thus reducing the draft seen in the flue.

The draft regulator is not properly adjusted. One of the basic tune-up steps performed on oil fired heating equipment, usually right after the system is serviced and cleaned, is to check for proper draft over the fire and in the flue. The in-flue measurement is usually made through a hole drilled in the space between the top of the heater and the under-side of the draft regulator. See What is the Right Draft Measurement at Oil Fired Heaters?.

The draft regulator hinges or pivot pins are sticking. On occasion, especially if someone was trying to "adjust" a draft regulator or damper by bending or banging on it, we find that the regulator's door hinge sticks. The door may stick in the open or shut position, interfering with proper operation.

It's easy to check for this sticky hinge problem: just gently push the door open and shut with one finger - it should move freely. When the oil burner is off and the system is cool, if you can push the regulator flapper door into a position in which the door sticks and does not return to the "closed" position on its own, the hinge is binding or the damper is not properly installed. Sometimes a little cleaning and a dab of oil on a hinge (I used pencil lead) is needed. If parts are badly rusted or smashed, just replace the unit.

The damper is installed on a shared flue or shared chimney: while it is not a recommended practice, if the damper is installed on a flue vent connector ("flue pipe" or "stack pipe" - the metal pipe connecting the heater to the chimney) that is shared with other heating appliances, then heat in the other appliance that is running or that has just shut down and is also "hot" can cause enough up-draft to cause the damper door to open.

In addition to the fire safety and code issues that severely limit any sharing of actual chimneys, the reason that manufacturers recommend that each heating appliance have its own flue damper is exactly this: you cannot adjust the barometric damper or draft regulator to optimize the performance of more than one heating appliance on a shared flue. Details are at Shared Chimney & Shared Flue Hazards.

The draft regulator is not properly installed - out of level or in the wrong location. A key reason that the manufacturers of draft regulators want the regulator face or "door" to be in the vertical position and the hinge axis of the door to be horizontal, is that the weight and calibration of the draft regulator adjustment and the response of the draft regulator to changing draft conditions depends on being in that position.

Even if the heating service technician adjusted the regulator for proper draft when the oil burner was up to temperature and running, if the damper is not properly installed it may not respond just right to changes in draft conditions such as wind over the chimney top.

In addition to out of level or wrong location, Field Controls also notes that the opening of the draft regulator should be pointing away from nearby walls or obstructions as these will interfere with its proper operation. Even if the installer placed the draft control properly plumb and level on the flue tee, if s/he forgot to set the locking screw (found at the bottom of the draft control assembly), the regulator may have rotated in its mount and may now be improperly positioned. [1]

Outdoor conditions are causing excessive chimney draft. For example at some building sites and depending on variables such as wind direction, nearby hills, chimney height, roof shape, height of chimney top above roof, chimney cap design, nearby trees or other obstructions (yep there are a lot of variables), wind blowing over the top of a chimney can actually increase the chimney draft to a too-high level, causing the barometric damper to open even if the oil burner is not running.

Question: our draft regulator door gets "stuck" then bursts open with a loud explosion noise - scary!

Hi there -- My home has both heat pump and oil heat and I prefer to use the oil. I have a ? - several years ago our elec co came and installed a programmable thermostat as well as doing something to our furnace.

Since that time there have been several incidents that the damper door gets stuck and then "bursts" open with a loud explosion noise -- scary. A local HVAC co replaced the door but the problem with the damper door still exists. T

he hubby has adjusted some weight on the thing but ... You would have thought the folks that replaced the door would know what to do. I'm afraid to have to use it and the heat pump is worthless. Any advice would be greatly appreciated. I reside in MD.

Reply from reader Lionel Scott

Mary get someone you know who knows heating systems, if he arrives with out his test equipment do not let him try to set up the burner or adjust the draft regulator as its job is to maintain the fuel air ratio when the outside conditions try to change it. It can not be done accurately by eye.

Reply from DF: a sticky barometric damper door is easily repaired but that's not the whole problem here - watch out for dangerous boiler or furnace puffback

Mary: a bent pin or even out of round opening can cause a barometric damper (draft regulator) door to "stick" closed. It's a simple mechanical repair that is easily performed by an attentive heating service technician. Or if the device is badly damaged or missing parts, it's not costly to replace the whole assembly.

Hubby changing the weight setting on the draft regulator door is not a good idea, though freeing up the door to move is just fine. The weight setting is a draft adjustment. Incorrect draft means incorrect burner operation.

Watch out: a stuck-shut draft regulator results in increased draft over the fire - something that increases heating system operating cost, but not something that would easily explain that loud "explosion noise" when the regulator opens. Rather, I suspect that your oil burner is not properly adjusted, is dirty, or is otherwise malfunctioning.

For example, an oil burner that does not shut down crisply at the end of a burn cycle can dribble unburned oil into the combustion chamber. At the next startup operating cycle that unburned oil is ignited to cause an explosion in the combustion chamber - referred to in the trade as a "puffback". Puffbacks can be dangerous, damaging the equipment and risking blowing soot all over the place, and in extreme cases the whole heating appliance can be badly damaged.

In conclusion I agree with Mr. Scott's advice: you need a service call from a trained, competent heating service technician, ASAP.

Question: I smell exhaust fumes after the oil burner shuts off. How can I track down that problem?

HI, I have a oil fired boiler that provides hot water base board heating and domestic hot water. I have just had the boiler serviced which includes cleaning and checking of draft etc. The serviceman is very competent. He has been servicing it for years. The flue is an 8" flue inside of a 10" insulated pipe because the pipe goes up a boxed in chimney of plywood and the plywood is stucco outside. I have a gas fire place also which is direct vented to the outside.

The flue pipe comes up the side of the box and then once it gets past the fireplace vent is offset to the center of the box. I believe the pipe is then reduced at the top to a 6" pipe and cap. It has been this way for 15 years, but suddenly I am smelling exhaust fumes after the burner runs and sometimes after it shuts off. The service man has been back several times and have tried different things and made sure the setting for draft are correct. He said the pipe is very clean and the furnace runs very efficiently

. I only seem to smell the fumes at the first level floor and not in the basement.

The next step would be to remove the outside surface of the box to see if we can see any separations where the pipes lengths connect, but I want to make that the last resort, because of the expense. Is there any other steps I can try to see where the smell is coming from. - Steve Henninger

Reply: have an expert inspect and fix any chimney, flue, or flue vent connector or draft regulator problems; check the oil burner for improper shutdown.

Steve Henninger,

If your heating appliance was designed for an 8" flue, that is, the diameter at the top or back of the heater is 8" in diameter, then any reduction to 6" is asking for a draft problem. It's true that a heater might appear to work "fine" with a constricted draft, especially if it were set up to give priority to the draft (perhaps at the expense of most economical operation). By that I mean it's possible to set an oil fired appliance to run "hot" to get better draft, and even to run cleaner, but setting hotter than normal wastes fuel, sending more of each heating dollar up the chimney rather than into the building.

Now later, maybe years later, fussy technician shows up, cleans and services the system, and sets it up at what s/he views as optimal for economy as well as safe operation. But now the constriction at chimney top begins to make more trouble.

Or alternatively, the chimney itself has changed - a leak or hole, combustion air supply to the appliance has changed -someone closed a door or window, or site conditions have changed - someone cut down a tree, wind direction changed or increased, etc. Something that just pushes draft problems over the edge of recognition.

• Check the whole chimney assembly: I'd ask for a thorough chimney inspection by a certified chimney sweep, making sure that the entire length of the flue is undamaged, that a properly sized cap is on top, etc. That, followed by draft measurements ought to tell us what's going on.
• Check oil burner operation: I'd also ask the heating service tech to check the fuel unit assembly on your oil burner. If the oil burner is not stopping the oil flow properly at system shutdown the burner may be sending incompletely burned oil into the combustion chamber, adding to smells at the end of a burner cycle and risking a dangerous puffback. Combustion air problems, a dirty nozzle, or similar problems can also cause dirty burner operations, sloppy shutdown, sloppy startup, or even leaks in the oil line can lead to the odor problems you describe
• Check the gas fireplace: also make sure that your gas fired fireplace is working and venting properly. Your question seems to point to the oil burner operation, but it's very important to make sure that any gas fired appliance is also operating safely in order to avoid risk of a dangerous carbon monoxide problem. (Make sure you have working CO detectors installed.)

Question: the chimney cleaner vacuumed through the damper and damaged it.

I just had my chimney clean and they put the vacuum into the damper instead of going into the sealed opening in chimney . I found my damper damaged the counter weight was on the floor . Is this standard practice in the chimney cleaning business practices. I will be making a complaint to consumer affairs and suing them for exposing me to carbon monoxide poisoning. Neil

Reply: repair the barometric damper or replace it; have the chimney and heating appliance properly cleaned and serviced

Neil, in my OPINION, it sounds as if your service tech may have taken a bit of a shortcut. Certainly if there is an easy direct view into a "dead end chimney flue" through the damper I can understand the temptation to just reach the vacuum in through the damper to vacuum out the debris - an important safety step to avoid a blocked flue.

But if you were having the heating system serviced and cleaned (that is your boiler or furnace was supposed to have been cleaned), on most systems it is necessary to remove the flue vent connector, damper assembly, and flue connection to the chimney as well as the top of the boiler or furnace in order to vacuum out the heater itself.

And if all that disassembly were performed, it would be easier then to vacuum the chimney base directly.

Further, what you describe is not a complete chimney cleaning - just removal of debris from the chimney base. Now that might be all that was needed, provided that the service tech had some reason to be confident that the rest of the chimney was clean and unblocked. Say by inspection using a mirror and light? But it's difficult to look up into a chimney thoroughly - it's like peering into a black abyss.

Damper parts on floor = very poor workmanship

Finding your damper damaged and the counter weight on the floor is prima-facae evidence of an incompetent technician. No responsible person would leave equipment in that condition. I'd give the heating or chimney company service manager a polite call asking that they send someone with better training and work habits to repair the damper and to inspect the chimney, and if your heater was supposed to have been cleaned, to perform that task too.

Sue for CO poisoning risk? Focus on safety first!

About suing your contractor for CO poisoning, I understand that you're rightly annoyed, but in my OPINION that's a costly waste of time and source of unnecessary aggravation for you as well as everyone else. Focus first on making sure that your heating system is properly serviced and safe. It would be in my OPINION a big mistake to start by hiring a lawyer while leaving the heating system in an unsafe condition.

Questions & Answers regarding this article

Questions & Answers about draft regulators and barometric dampers on heating equipment; Questions & Answers about inspecting and adjusting the barometric damper or draft regulator on oil fired heating equipment

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CARBON MONOXIDE - CO
CARBON MONOXIDE WARNING

CHIMNEY INSPECTION DIAGNOSIS REPAIR
CHIMNEYS & Flues - Asbestos Transite Pipe

Chimney Draft & Performance
  Draft: Thermal Performance of Chimneys
Chimney Height & Clearance
  Chimney Too Short
  Masonry Chimney Roof Clearance
  Adjacent Metal Chimney Separation
  Chimney Height for Types L & Type B Vents
  Chimney Height Extensions
  Wood burning Fireplace Roof Clearance

COMBUSTION AIR
COMBUSTION AIR for TIGHT buildings
COMBUSTION GASES & PARTICLE HAZARDS
COMBUSTION PRODUCTS & IAQ
COMPLETE COMBUSTION, Stoichiometric
COMBUSTION GASES & PARTICLE HAZARDS
COMBUSTION PRODUCTS & IAQ

DIAGNOSE & FIX AIR CONDITIONER / HEAT PUMP
DIAGNOSE & FIX HEATING PROBLEMS-BOILER
DIAGNOSE & FIX HEATING PROBLEMS-FURNACE

DRAFT HOODS - gas fired
DRAFT MEASUREMENT, CHIMNEYS & FLUES
DRAFT REGULATORS, DAMPERS, BOOSTERS
  Purpose of Barometric Draft Regulator
  Measure Draft
  Barometric Damper Defect List
  How to Inspect a Barometric Damper
  Automatic Vent Dampers
  Define flue damper, duct damper, & fire damper
  Draft Inducer Fans

Also see OIL BURNERS and OIL BURNER NOISE SMOKE ODORS

• [1] "Instructions for Installing FIELD Type AF Barometric Draft Controls," Form No. 31 DC 30666, Field Corporation, Mendota, IL 61342, web search 04/02/2011, original source: http://www.fieldcontrols.com/pdfs/04592700.pdf, Field Controls, Kingston, North Carolina 28501, Tel: 919-522-3031
• [2] Tjernlund Draft Controls, A Series (single action for oil, solid fuel, and fan-assisted gas burners) and B Series (double action for gas heating appliances), web search 04/02/1011, original source: http://www.tjernlund.com/Tjernlund_8500490.pdf , Tjernlund Products, Inc., 1601 Ninth Street, White Bear Lake MN 55110-6794, Tel: 651-426-2993 or 800-255-4208 website: www.tjernlund.com Email: fanmail@tjfans.com
• Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. (416) 964-9415 1-800-268-7070 info@carsondunlop.com. Thanks to Alan Carson and Bob Dunlop, for permission to use illustrations from their publication, The Illustrated Home which illustrates construction details and building components. Carson Dunlop provides home inspection education including the ASHI-adopted Home Inspection Training Program (home study course), publications such as the Home Reference Book, report writing materials including the Horizon report writer, and home inspection services. Alan Carson is a past president of ASHI, the American Society of Home Inspectors.
• Lonny Steinke, Worland, WY USDA kindly corrected erroneous data we published on the proper draft numbers. - October 2008.
• Dirk Faegre, Camden, Maine (207) 232-9494 is a certified  BPI  energy auditor and certified Envelope technician who kindly suggested draft regulator and flue vent connector inspection defect additions 6 Sept 09

What is an automatic duct damper and how do they work?

What is an Automatic Fire Damper in Ductwork and how do they work?

• A fire damper is required in air conditioning and heating ducts in some commercial installations and possibly by local residential building codes in some jurisdictions.
• A fire damper might work similarly to an automatic duct damper, but its purpose is quite different: in the event that a fire is detected in a building or in its mechanical systems, (by heat or smoke or other means of fire sensing), the fire damper closes off the air duct to avoid spreading smoke or fire rapidly through the building. The fire damper is otherwise normally "open".
• You can see photographs of and read about fire dampers in ductwork at ZONE DAMPER CONTROLS .

What is a Draft Inducer Fan and how do they work?

What is a Barometric Draft Control and how do they work?

Dirk Faegre, Camden, Maine (207) 232-9494 is a certified  BPI  energy auditor and certified Envelope technician who kindly suggested draft regulator and flue vent connector inspection defect additions 6 Sept 09

Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

• Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.

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