How & Why to Open & Inspect Barometric Dampers & Draft Regulators on Oil Fired Heating Equipment
InspectAPedia® -
How to inspect the oil fired boiler or furnace flue through the barometric damper opening
How to interpret the level of soot or debris inside of oil fired heating equipment chimneys and vents
Draft Regulators & Barometric Dampers: A Guide to Barometric Dampers on Oil Fired Boilers, Furnaces, Water Heaters: inspection, adjustment, cleaning, troubleshooting
Cleaning & maintenance guide for heating systems
Questions & Answers About Soot, Rust, Debris Seen in the Heating Flue
This article explains the procedure for opening and inspecting heating flues through the barometric damper or draft regulator.
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In addition to this detailed damper inspection procedure, readers should be sure to review Barometric Damper Defect List. 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.
How to open and inspect a barometric damper for Inspection
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 at DRAFT REGULATORS, DAMPERS, BOOSTERS 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. Contact us to suggest text changes and additions and, if you wish, to receive online listing and credit for that contribution.
This article discusses the simple but very useful step of just taking a quick look into the flue pipe through the barometric damper opening on oil fired heating equipment.
At Measure Draft we also discuss how and where to actually measure the heating equipment draft in the course of checking on (or adjusting) the draft regulator.
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.
Barometric dampers are devices used to regulate the draft on oil-fired heating equipment such as furnaces, boilers, or
water heaters.
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.
In our photo you may not be able to open this barometric damper - it is improperly installed (out of level), and has been improperly modified, indicating a draft problem with this heating system or its chimney. The implications of sealed barometric dampers are explained at Draft Regulators for oil fired equipment.
How & Why Should You Open & Inspect the Barometric Damper:
When I, the author (DF) first owned a home with a heating boiler I was so terrified of this rumbling flickering box in my basement that I didn't even walk near it. That was a mistake. And we wasted lots of money on oil before we learned that just a few simple visual checks can tell a lot about how well our heating equipment is running.
So don't worry: it's easy to perform this step - anyone can do it if a barometric damper is actually installed where it should be. Just gently push the hinged door open with a finger, and shine a good flashlight inside to see what you can see.
Warning: of course if your oil fired appliance has been running recently, these parts are HOT and you could get burned. If the damper door itself is hot you can still look inside - just use a screwdriver or wire to push the door open rather than your finger as shown in our photo at left.
A barometric damper installed on a horizontal flue pipe will give a good view of the cleanliness of the flue interior as well as clues about rust and damage in the flue.
A barometric damper installed on a vertical flue pipe may still give a good view of the top of the heating boiler, furnace, or water heater, where you may see accumulated soot or debris, rust stains, or perhaps better news.
Guide to Interpreting Debris Visible in the Chimney Through the Cleanout or Draft Regulator
Debris visible in the flue vent connector (stack pipe) visible through the barometric damper draft control opening. If you see soot, rust flakes, and debris in the flue vent connector this means that the heating system needs to be cleaned and serviced.
If the heating system has "just been serviced" this debris means that service was incomplete.
A flue vent connector ((also called the "stack pipe" or "flue pipe") is the metal pipe that connects the oil fired heating appliance to a chimney in order to safely vent combustion gases outdoors.
A proper service procedure for oil fired heating equipment includes removal of the flue vent connector and thorough cleaning of all debris from these components as well as a visual inspection of the condition of the chimney to which the flue vent connector joins to send combustion products outside.
Our photo shows what was probably several years of accumulated soot, rust flakes, and debris in the flue vent connector of an oil-fired horizontal furnace in a wet moldy crawlspace. The owner thought that his system, which was almost impossible to access, had "just been cleaned".
Opening this damper and looking inside meant we literally "hit pay dirt". The dirt meant that the system needed to be cleaned, that the owner was paying for heat, but the heat was going up the chimney, not into the home -- as we explain a bit more below.
A hard to access heating system in a cramped nasty area rarely receives thorough cleaning and service. That was the case for this system.
Questions & Answers About Soot, Rust, Debris Seen in the Heating Flue
Question: What is the significance of those "rusty flakes" in the photo of crud visible at the chimney base or through the barometric damper
When I cleaned our flue exhaust, I found 'chips' in the soot like the ones in the image. What are those? I thought they might be from the flue lining chipping off. Are they? - Jessica
Reply:
The "chips" such as those in our photo are typically soot-coated rust if the flue is metal, or soot-coated flakes of the glazing that was protecting the interior of a clay tile lined chimney flue.
The implications of the chips are that the hard glazed coating is being lost and thus the flue is deteriorating. Just how deteriorated the flue is we can't say from a photo like this one, but it is an indication that a more expert chimney inspection is in order. Use a professional chimney sweep and ask for a complete inspection of the chimney flue interior.
Loss of the chimney tile surface exposes the chimney flue liner to an ever increasing rate of deterioration, especially in climates of harsh or freezing weather. When the chimney liner deteriorates that means that eventually it can become unsafe, risking flue gas leaks, carbon monoxide poisoning, or even sparks and a building fire.
See Chimney Cleanout Doors for more examples of things you may find at the bottom of a chimney when inspecting through the cleanout door, or if it's a "dead end flue" you may find these inspecting through the flue vent connector or, if the flue is without bends and elbows, you may be able to inspect right through the barometric damper such as in our photo above.
When & Why is soot or crud in the oil fired boiler or furnace flue a problem?
When we look in to the flue close to the heating boiler or furnace, such as at the barometric damper shown at the top of this page, it's normal to see a thin coating of soot on the interior of the metal flue pipe (photo at left and photo at page top). .
But thick soot in the flue, the chimney, or inside of the boiler or furnace heat exchanger is a problem (photo below).
Our photo of a soot problem indicator (left) shows soot accumulating in the oil burner flue of the heating boiler connected to the "too short" chimney discussed at Chimney Height & Clearance.
This boiler has a history of blowing soot out of the boiler room and through the garage of the home it serves. This same soot is, of course, accumulating inside the heating boiler itself.
Because soot acts like an insulating coating, too much soot in a heating system causes both system operating problems problems and increased heating cost for the building.
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Additional technical contributors & reference sources for this article are listed below.
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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
Thanks to reader Jessica for discussing chimney debris found by inspecting through the draft regulator - November 2010.
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.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 2010, $69.00 U.S., is available from Carson Dunlop. The Home Reference Book is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. InspectAPedia.com ® author/editor Daniel Friedman is a contributing author. Field inspection worksheets are included at the back of the volume.
Domestic and Commercial Oil Burners, Charles H. Burkhardt, McGraw Hill Book Company, New York 3rd Ed 1969.
National Fuel Gas Code (Z223.1) $16.00 and National Fuel Gas Code Handbook (Z223.2) $47.00 American Gas Association (A.G.A.), 1515 Wilson Boulevard, Arlington, VA 22209 also available from National Fire Protection Association, Batterymarch Park, Quincy, MA 02269. Fundamentals of Gas Appliance Venting and Ventilation, 1985, American Gas Association Laboratories, Engineering Services Department. American Gas Association, 1515 Wilson Boulevard, Arlington, VA 22209. Catalog #XHO585. Reprinted 1989.
The Steam Book, 1984, Training and Education Department, Fluid Handling Division, ITT [probably out of print, possibly available from several home inspection supply companies] Fuel Oil and Oil Heat Magazine, October 1990, offers an update,
Principles of Steam Heating, $13.25 includes postage. Fuel oil & Oil Heat Magazine, 389 Passaic Ave., Fairfield, NJ 07004.
The Lost Art of Steam Heating, Dan Holohan, 516-579-3046 FAX
Principles of Steam Heating, Dan Holohan, technical editor of Fuel Oil and Oil Heat magazine, 389 Passaic Ave., Fairfield, NJ 07004 ($12.+1.25 postage/handling).
"Residential Hydronic (circulating hot water) Heating Systems", Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
"Warm Air Heating Systems". Instructional Technologies Institute, Inc., 145 "D" Grassy Plain St., Bethel, CT 06801 800/227-1663 [home inspection training material] 1987
Heating, Ventilating, and Air Conditioning Volume I, Heating Fundamentals,
Boilers, Boiler Conversions, James E. Brumbaugh, ISBN 0-672-23389-4 (v. 1) Volume II, Oil, Gas, and Coal Burners, Controls, Ducts, Piping, Valves, James E. Brumbaugh, ISBN 0-672-23390-7 (v. 2) Volume III, Radiant Heating, Water Heaters, Ventilation, Air Conditioning, Heat Pumps, Air Cleaners, James E. Brumbaugh, ISBN 0-672-23383-5 (v. 3) or ISBN 0-672-23380-0 (set) Special Sales Director, Macmillan Publishing Co., 866 Third Ave., New York, NY 10022. Macmillan Publishing Co., NY
Installation Guide for Residential Hydronic Heating Systems
Installation Guide #200, The Hydronics Institute, 35 Russo Place, Berkeley Heights, NJ 07922
The ABC's of Retention Head Oil Burners, National Association of Oil Heat Service Managers, TM 115, National Old Timers' Association of the Energy Industry, PO Box 168, Mineola, NY 11501. (Excellent tips on spotting problems on oil-fired heating equipment. Booklet.)
Links to our list of additional information on heating system inspection, repair, maintenance
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