How to set the oil furnace barometric damper 

Thank you for all of the videos that you post. I am getting ready to go to school to be an HVAC technician and i watch all of your videos to get a jump start on the learning process

This man knows what he's talking about he has years of experience ..Most important he shows you what will happen from one setting to the other..Troubleshooting,,best on RU-vid,,,TY...Gray

Thank you for the plugged heat exchanger comment. That was huge for me. Gosh there is so much I thought I knew but I don't. Even after 30 years working in the hvac world.

Your videos are very informative.Thanks for sharing. I do not miss any! Even though I do this everyday as an hvac service tech. I learned that the real school is out in the field. Congratulations.

All oil furnaces should have a draft diverter installed from the beginning. You’re one who really knows how to interpret the draft readings. I’ve cleaned out my share of oil furnaces, that were running a positive pressure over the fire.

Thanks very much, your videos and info are the best !!!

an important adjustment, thank you...

I know nothing of the pressure, or enough to know I shouldn't mess with it as a layman. I just oiled the swivel and wired a rig to keep it from locking in its extreme open position and eliminate the noise. It's real windy right now here and it is reactive to the wind. I wanted to keep the noise down (the bang-banging) as it returns with its force to it's resting position too without at all hampering it's full pendulum motion. Success, nothing but silence from the confounded (albeit important) contraption! Thanks for the explanations and expertise - very cool and informative video. My maintenance guys tell me the whole system is working really well - which is terrific considering how old the system is. Just a lil oil here and there (especially in the forced hot air motor) works wonders.

Great explanation, thank you

Very informative. Thanks alot.

Great video!! Thanks.

Thanks for showing everyone what not to do. Looks like you are on a positive scale

Great video! Thanks for sharing!

VERY smart devise!!!

this is great!

Pressure in the combustion chamber ..... on burner manual they have that to on mbar in europe...... we haft to be on this levels like manuals or we can ritch it all the time?

Very informative, thank you. What happens when you have 2 appliances connected to the same chimney (furnace + water heater) ? Can you make a video about fresh air intake and back drafting problems ?

When using a digital manometer is it better to put a 90° bend in your copper tube, or just go straight in?

Since I have approximately 12 feet of 4 inch flue pipe including the 4 feet of insulated pipe up the outside of my greenhouse for my miller. I’ve never had any issues that I know of. But do you think that I should have a 4 inch barometric damper in the beginning of the pipe coming from the top of the miller or do you think 12 feet of 4 inch pipe is ok to run the miller this way I’ve had it this way for 3 years. I was thinking maybe with out a barometric damper it might be causing back pressure. But was worried that if I installed one that the flue gases would take the path of least resistance and then just come out of the damper into the greenhouse. The only reason I ask is because if we have any more major issues with this furnace since it is used I will be replacing it with a new unit from Thermo pride that makes a identical replacement with the same 4 inch vent and definitely would not want to damage a new unit with a long 4 inch flue pipe.

Very nice, well put together

How would I adjust a single barometric damper that services both an oil boiler and an oil hot water heater? Would I adjust it for the boiler or the hot water heater? if the boiler, how would it affect the hot water heater and what happens when they fire both at the same time? These situations are not addressed in the video :( Thanks!

Good video. I have a question. When you were checking the pressure below the damper, why is there 2 tubes on the manometer? Just wondering what that other one is used for. Thanks

Your videos have been very helpful, thank you. I bought the manometer you use and it's very erratic. The measurements range from 0" WC to -.12" WC. Do you know any possible causes? I'm thinking of returning the manometer for another.

is upside down bad? and what size damper is that. Do the backside counter weights ever need adjusting?

have you done any videos with gas draft diverters? I'm trying to understand how i have good draft above the hood, but around the draft hood opening doesn't seem an extinguished match smoke is drawn in. Also testo 327 show 1 ppm co

Thank you for sharing. Our oil fired boiler damper remains open after combustion has ended, sometimes 30 min to several hours. If I flick the damper it will then close. Is it correct for the damper to remain open after combustion has ended or does this mean it might require adjustment?

I have question on my furnace I only get o readings on manometer. same meter as yours even with damper sealed closed. What would cause this. I have a tall mason chimney and no smell in basement. also on windy days damper will open even with furnace off.

What do you recommend for running that intake pipe, outside? To keep it from creating a vac in the conditioned basement? Is that possible? I have a blown air oil furnace, %84 afue. Installed in 06. Debating on upgrading what i can or replacement. Tigerloop. Insulating pipes, etc

Great video. My damper, which is partly open when furnace isn't running, always seems to close mostly shut when the oil burner kicks on. Is this opposite of how it is supposed to work? I thought the heating of the flu would increase draft and cause the damper to open a bit when burner is on.

Thanks for sharing information about this damper. I've had technicians that come out for my oil boiler tune ups tell me, on at least three occasions "You don't need to worry about your damper" "It's an archaic 1970s leftover", etc. I've repeatedly asked them to adjust it properly, and they all say "it doesn't matter, don't worry about it. We don't even carry a barometric pressure reader on our vans to read it" Are my oil provider's techs being truthful?

My oil burner has no vent/damper on the chimney. There is a 2.5 x 4.5 inch door just above the burner that lets me look into the slot in the combustion chamber. This door has a screw allowing it to be adjusted to hold open at varying amounts. Anyone know if this should be adjusted like the damper?

Also, on another note...What if your barometric is at a 45 degree angle on the flue... Would you put your weight on the V or H position for Vertical or Horizontal?

Good evening gray furnace man I have a question I have a Burnham boiler and I have a 8 inch stack. It’s got the same set up as you working on here and in a windstorm. It’s blowing off my smoke detector carbon monoxide detector rather I don’t know how to adjust it I don’t wanna mess it up. Can you be of any assistance?😊

Thanks for a good video. What gauge are you using to measure the pressure?

Your digital gage reads positive pressure, should it be negative or positive. Some Carrier oil furnace are designed to run in a pisitive draft while running.

I measure .035-.04 in the over fire position and .035 (this the maximum I can get with the damper fully closed) in the flue ahead of the damper. Is my chimney too short? How do you reduce the vacuum in the burner area? It has a screw on the observation flap into the burner area - is the idea to open that to drop the over fire pressure? Also, I'm getting a small amount of smoke back into the building. How is that possible with a vacuum in the vent - again, is the chimney too short? It sticks up about 2 ft over the peak but there is another building next to it that is taller.

what is the problem and what we haft to do if the depression is out of burner table ?

I just bought a godin petite 3726 oval wood/coal stove. Can you please help me unfreeze a frozen air knob on the front? It is frozen solid in closed position I tried to open it with a grip lock pliers but just ended up damaging the porcelaine on the lug on the dial. Which way do I turn to open it and do you have a suggestion on how to unfreeze it. I tried wd40 on the bolt stem behind the door, as well as spraying the gasket with it. Any tip would be appreciated. Thanks.

I HAVE BEEN LOOKING FOR A GOOD VACUUM METER, WHAT BRAND AND MODEL DO YOU RECOMMEND?, great video by the way, Thanks

I just installed one where the weight and pivot are on top. Yours looks like it would be better if it was on the bottom half of the damper. Should I turn it around?

Thanks for sharing your knowledge. Shouldn't the readings be negative?

I believe my differential control is 10-15-20. .. With cast 180-220 is 40.

I have a question i installed a trailer furnace welding n my garage I'm wondering if I can put a damper on the pipe that goes outside because it doesn't seem to push hot hot air i think I'm losing my heat out my pipe

If you have a damper that you completely open with the weight slid all the way down and still get a negative pressure reading of more than .04, can you elaborate on the issue? Flue vent not high enough over roof? Anything else that could cause this???

How come the manometer is showing positive draft in the flue. I have the same meter but it shows a negative number. Been learning allot from your channel. My new oil fired boiler has a positive in the chamber and negative in the flue.

Where did you buy the probe that goes on the end of tube. I see your GSI video, but probe end not included. Thanks!

Do you know what would cause the damper to Slap close from time to time Would it have to do with positive pressure in house or possible short cycling of burner?

nice video where did you get your tester at like it

Just wondering why the draft regulator is installed with the weight at the bottom. I have never seen that before, I am used to the weight being installed towards the top of the smoke pipe. What is the logic behind installing it on the bottom?

GFM, Where did you source the prob at the end of your manometer? Can I use the static pressure probes like the one I use for my AC system for this? (I assume yes).

My heater does not have a barometric Damper. It is crawl space installed but I am wondering if I should fire the people that have serviced it and have one installed.

Just went downstairs and found my damper lying on the ground. The chimney clean out door was also open...what the heck is going on? I reinstalled the damper, but not sure I have it on right. It looks like the one in your video except the weight is on the inside. I installed it weight side down, otherwise it would just hang open when the furnace is not running. Is this correct?

GR8 VIDS! I WATCHED MANY.help??? mega info :) I CANT GET MY BECKET RUNNING RIGHT.theres a few things going on. the gap is even with the nozzle.only the electrodes stick past it.like theres no space.between the two.yet the elec is 1/16 past the nozzle technicly. their flat/no points and i see after 1 day the carbon is scoring on the bottom 1/8 on boyh electrodes.no scoring on nozzle..but nozzle has a darkish droplet stuck to its bottom.once it croaks totally i remove the gun,line and scrape everything down n it runs for a few hours... ITS STALLING AFTER 1 MIN THEN LLOCK OUT>pump goes 20sec b4 lock out " " " 2 min "" stumbles every 20 sec...sometime 1min..sometime never thru a cycle up to 12 min.. i jumped the cad eye no difference..ohms are 1500 off 500 on ....sometimes after it wont run past a min...40min later it WILL RUN A WHOLE CYCLE but stumble and catch stumbles usually 1/2 second..the longer it stubles the better chance it wont recatch.. again it wont run past 1 minute...it always runs dead for 20-30 secs b4 lock out. if i shut the heat off after a lockout.it will reset itself... just had full tune up. spark is hella strong!!looked too strong compared to utube tests...the aqua stat hums lightly..flame is bright orange/yellowish...on restart i never see a puff of smoke...IF IT DIES..I CAN TURN THE ON/OFF SWITCH AND IT WILL LIGHT RIGHT BACK UP FOR A MINUTE AT LEAST...once the on/off switch wouldnt even trigger the cad box took 10min to reset somehow....theres a spring loaded check valve in the gun fuel line im getn susiscious of..i blow the line out by mouth and oil comes out in a straight stream pretty easy..the B.damper dances pretty hard constantly.seems like somethings killing spark,,those 20ish seconds the pump is going w/out fire,i see no light thru the crevices and cracks by the coil..sometimes it runs nice catches every stumble fast..sometimes it does the 1min/2min thing or 40sec. its like a crapshoot everytime it clicks on!!!!!!! when i take the tiny oil line off to remove gun,i never see any dripping oil.yet the gun is 30%full.?also under the gun i s wet. not much just a thin coat..it never ignites,it might be moisture 4 all i know.

When I have my boiler adjusted the best I can, testing draft over fire and 0 smoke, at times, cold weather, the damper gets maxed out, running wide open. Wasteful sucking all that warm air up the chimney to keep the boiler to spec. Any acceptable way to decrease the draft of the chimney? I have stuck some bricks in the hole where the stack goes in the chimney and it helps a bit. Can't see any harm as I still have plenty of draft in summer and bricks don't burn. Replaced all of the turbulators awhile back, 18, with twisted spiral ones. Stack temperature down to more acceptable level now.

hello. I have a 10" flue, should I look for a 10" barometric damper or can a smaller damper work?

Read proper installation for barometric dampers, To close to Breach ! Draft over the fire on a clean flue passage - heat exchanger, Draft over the fire should be set to Neg-01 or Neg.02 max this is explained by most oil burner manufactures. Get over fire draft set Neg -.02, Then do smoke testing and Co2 reading and others, Then again check draft over the fire and make sure its within Neg -.01 to .02 max when done! If higher readjust barometric damper, Higher draft over the fire sucks out flue gases to quick. If to high Neg -.4 and higher over fire draft this will throw off Co2 reading and smoke test. Trust me been doing this 28yrs licensed for most everything! Some Oil fired Manufactured appliances with poor design heat exchangers may not want a barometric damper ( rare ) and we know who they are. Keep in mind new heating systems on Old Chimneys you might not get any draft over the fire! Then you need a chimney liner for the total btus and don't forget to insulate the new liner on an outdoor chimney and some indoor chimney sections exposed to outdoor temps. The Boiler Man LLC

can i angle my becket oil burner vent pipe in my attic which is about 6' in length in order to get it on back side of roof ridge ? Beckett NX burner, high efficiency furnace. Pipe is b vent. thanks

Hello. What should the high and low temp be set at? . And the differential? Thanks

I think it’s just because of the design of the crazy heat exchangers that Millers have that you never can get a true negative draft at the flame inspection hole because normally they are just vented straight out the roof. when I open the little inspection door to look at the fire it goes from negative to faint positive negative to faint positive and so on and that’s what my service guy that looked at it said it has a hard time establishing draft I think.

Can you leave those two holes open, or is that just for testing?

Hi GFM. I have what looks like the same model manometer as yours, but can't seem to get an accurate reading out of it below 0.10 (as in it seems to only start reading from 0.10 and then up in 0.01 increments - 0.00 reading prior to that). It is a HT-1890 readily available on eBay and might not be the same as yours. I can't see from the video where you have the other hose/probe you aren't using, or is it just hanging down and not important? Does it need to be connected and at the same length as the hose you are testing with? The "instructions" that came with the unit aren't any help... Cheers

This may be a stupid question, but how come you never see those barometric dampers on gas furnaces? Most of the time when I test, the draft is high, and this would be an easy fix rather than getting into resizing vent pipe. The only time I would see a damper would be if it has a side vent kit. Maybe you can do it, and its just not popular, but I can't recall ever seeing one. thanks

many questions :-) if i have to mutc noise of the burner noiller and exsaust , waht can i make to minimise the sound? i must play with the head to open it or close it? the air ? smaller nozzle? put in your mide , i cant change the pipe of exsaust because many people they dont want toi give moeny for that , so i want a solution with that !

I have an oil burning hot water heater and furnace sharing the same metal chimney. each have their own barometric damper like the one above. Watching the hot water heater run.. I see its damper rock back and forth.. when the burner goes out, the damper rocks closed. When the furnace is running.. it's damper doesn't really move, but it does move the water heaters damper instead. when the furnace burner goes shuts off.. both the furnace damper and the water heater damper fly WIDE open for a second and close. What would cause that kind of sudden draw when the burner goes out. Is something wrong? because the water heater doesn't do that and they're connected to the same chimney pipe. Chimney has been swept within a year and both burners cleaned and nozzles changed at the beginning of this heating season.

What is that probe that you have attached to your manometer tube? Is that just a piece of copper tubing?

If your at .04 draft at breech, with .02 over fire you have one clean boiler.

when our oil furnace is not running , we have quite the downdraft , that blows out into the furnace room via the damper , with the -20 degrees C this is a real lose in heat. are there any dampers that are better at being airtight than others when not in use.

you can control the depression off boiler with that way?

I'm missing that weight and I don't know what is called or where to get it

where did you get your draft gauge, I like it.

I just bought the same manometer. I’m confused. What unit of measurement to I set it on for the same testing you show in the video?

I have a Williamson Highboy Oil Furnace by Metzger mfg in 1999 and my over fire reading is -1 and overdraft reading is -1 and cant seem to increase my overdraft to -2. Specifications call for -1 to -2 for over fire and -2 to -3 for overdraft. Thoughts? thank you

I am trying to figure out what causes a rumble at startup, when the burner kicks on after delay the damper slams shut quickly once and then works as normal. Eff test: 0 smoke, 11.5% CO2, 5.5% O2, Overfire Draft -.01 to -.02" wc, Damper Breech draft -.06"wc. Runs fine but damper slams at startup and there is a slight rumble at startup, oiled fired furnace.....any thoughts? thanks

What is the device called you are using to measure the air pressure in this video?

Wondering why your manometer is showing a positive pressure draft instead of NEGATIVE (-) .02 and .04 respectively?

This device is at the bottom edge of it's scale, how you can say it is 0.01 or 0.02 difference? Could as well be 0.03 or less than 0.01. Considering the measurement on top was made with tube pointing down, toward the stream of running gasses which would slightly increase readings due to dynamic pressure added, I'd say static pressure difference is 0.01 or less. Need more precise or analog device here to tell better.

The weight for the draft regulator is on the wrong side, should be on the right when installed in a vertical tee

That is a good vedio

Do I need a damp my oil stove has a stove pipe that's about 6ft long can't go longer

What kind of end do you have on the tubing?

The damper is upside down. This installation is not shown as being approved in the Field Controls literature. Also, I would have expected you to discuss the counter weight being set on the correct side: vertical vs. horizontal chimney connector orientation. Otherwise, another good video grayman. Thx.

What's the gauge you're using? Can I get it at Home Depot, etc.?

my boiler has the baro damper mounted horizonally at the rioght side of my boiler. The main stack, goes out to the left and runs about 40ft, to a power venter. The damper has the adjustment weight located at the top of the valve. is the correct position? in your video, i see the adjustment screw at the bottom. Which position is correct? Thank you.

What would cause a damper to slam back and forth ?

If the pressure was negative, why didn't the meter show "-0.04?" It seems like at times it was showing negative and at times positive readings. Specifically at the 2:00 mark.

Reasons like this, can’t wait to get ride of our oil furnace at the cottage. Such a problematic system, dirty, issues, just junk and needs to be replaced by the future. Keep diesel in trucks Great info but just such a useless mode of heating

What tool is that?

My vent is always open . Even while the boiler is not running. Is that not oka?

How to adjust air in Reilly berner

Sir what is the name of that tester machine?

Mine blew off and flew 10’ yesterday , any answer to that?

What if you can't get more than about .02in/wc at the damper. Heat exchanger? Vent size? More likely all sootted up. Do to years of improper combustion.

What if you don't have a barometric damper?

How can I get a pressure gauge like that ? Thanks.

just try to find different answers. Someone said they like 180 h, 140 L

you're either in the middle of the Windstorm or your oil burn is running like s***

I have the manometer where I get that prove. Thanks

Thanks for posting the video BUT may I suggest you start out explaining 1) the physical significance of having the device in the exhaust of the heated, burn gas; 2) how is the device constructed so it would open by adjusting the weight and how the movement of air creating the negative pressure differential that would cause the flap to open and allows the ambien, unheated air to move in by the suction effect of the moving hot air, etc; otherwise, you are just telling the minute changes in the number but did not explain the meaning behind doing it. You may write and say you assume people already know what the thing does, etc.; if that is the case, then.....

is this the same on gas boilers?

The reason for a barometric damper is to maintain a constant pressure in the firebox.