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DIAGNOSE & FIX HEATING PROBLEMS-FURNACE
DIRECT VENTS / SIDE WALL VENTS
DRAFT REGULATOR, DAMPER, BOOSTER
DUCT SYSTEM & DUCT DEFECTS
ELECTRIC MOTOR DIAGNOSTIC GUIDE
FAN, AIR HANDLER BLOWER UNIT
FLOODED HEATING EQUIPMENT REPAIR
FLUE SIZE SPECIFICATIONS
GAS BURNER FLAME & NOISE DEFECTS
GAS PIPING, VALVES, CONTROLS
GEOTHERMAL HEATING SYSTEMS
HEAT PUMPS, DIAGNOSIS, REPAIR
HEATING COST SAVINGS METHODS
HEATING OIL PIPING TROUBLES
HEATING OIL TANKS
HEATING SYSTEM NOISES
HEATING SYSTEM TYPES
GAS LP & NATURAL GAS SAFETY HAZARDS
MANUALS & PARTS GUIDES - HVAC
MIXING / ANTI-SCALD VALVES
MOTOR OVERLOAD RESET SWITCH
NOISE, HEATING SYSTEMS
ODORS FROM HEATING SYSTEMS
OIL FILTERS on HEATING EQUIPMENT
OIL FILL PIPE LEAKS
OIL SPILL CLEANUP / PREVENTION
PLASTIC PLEXVENT ULTRAVENT RECALL
PUFFBACKS, OIL BURNER
RELIEF VALVE LEAKS
RESET SWITCH, HEATER PRIMARY CONTROL
RESET SWITCH, ELECTRIC MOTOR
RESET SWITCH, STACK RELAY
SAFETY, HEATING INSPECTION
SAFETY RECALLS CHIMNEYS VENTS HEATERS
SOLAR HEATING SYSTEM DESIGNS
SOOT on OIL FIRED HEATING EQUIPMENT
STEAM HEATING SYSTEMS
THERMOSTATS, HEATING / COOLING
VIDEO GUIDES: HEATING SYSTEMS
WINTERIZE A BUILDING
WOOD, COAL STOVES & FIREPLACES
WOOD STOVE SAFETY
ZONE VALVES, HEATING
How to inspect, diagnose & repair oil burners used on oil-fired heating boilers or furnaces using a visual inspection approach as well as (optional) simple test equipment. We include a description of common oil burner adjustment and operating problems and we illustrate some of the basic oil burner tests and measurements made in servicing and adjusting the equipment for safe, efficient operation. We illustrate oil burner smoke testing and oil burner carbon dioxide level measurement.
This article series answers most questions about all types of heating system troubleshooting, inspection, diagnosis, and repairs. We describe how to inspect, troubleshoot and repair heating and air conditioning systems to inform home owners, buyers, and home inspectors and students of heating service methods about common heating system defects. The articles at this website describe how to recognize common oil-fired heating appliance operating or safety defects, and how to save money on home heating costs
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In the oil burner inspection article provided here we explain visual and other clues of oil burner problems.
An expert inspection of an oil burner begins either with having made note of building owner/occupant concerns (noises, odors, no heat, high fuel costs), or with having made some basic visual observations outside: a sooty chimney top, for example. The sketch is courtesy of Carson Dunlop Associates. )
The oil burner inspection continues indoors, even before entering the utility room where the oil burner (or often more than one of them if oil fuel is used for both heating and a separate water heater) is located: look at the building interior as you enter: are there odors, soot deposits, noises associated with the heating system?
The oil burner inspection becomes detailed, and diagnostic, when you can actually see the equipment. It's obvious that you should notice oil leaks, soot in the boiler or furnace room, noises, odors, signs of repeated repairs, piles of junked parts, signs of unprofessional work (covers off of controls, sloppy wiring or plumbing). But just what each of these clues might mean bears some additional explanation that we offer below.
If the chimney top is sooty we don't yet know the cause of poor oil burner operation but we know there is a problem. If your inspection of the chimney top, even from ground level, perhaps with binoculars, shows water, frost, or mechanical damage to the chimney itself, or a missing chimney cap, these conditions may not only affect the operation of the oil burner, but they may be very unsafe. See CHIMNEY INSPECTION DIAGNOSIS REPAIR.
On entering the building or by customer interview, start with a check for these signs of improper oil burner operation, regardless of whether the burner is powering a boiler, furnace, or water heater:
We mentioned outdoor oil tank problems above, but even indoors you may spot signs of trouble that affect oil burner operation.
While it was possible to "eyeball" older oil fired equipment (spit on the flue for temperature and blow cigarette smoke at the burner for draft), modern oil fired equipment requires more accurate measurement and adjustment for good operation.
The Guide also includes this chart of oil fired heating system efficiency at different CO2 levels and stack temperatures.
The little hole we describe is where the service tech inserts test equipment to measure stack temperature, smoke level, and CO level. Some tech's use two holes to permit more than one measurement simultaneously. No hole = never measured. (Or new flue vent connector parts have just been installed on older equipment and no one has made a hole yet.)
Our photo (left) shows a Bachrach stack temperature measurement being made "in the breech" above a troublesome oil burner and boiler installation.
Watch out: don't record the stack temperature before the oil-fired heating system has been running for five minutes or so - you want to be sure the system has reached its stable and "normal" operating temperature.
Waiting a few minutes at this boiler we saw the flue temperature rise to 600 °F. At 600 °F. this heating system was left running a bit "hot" by the service tech. Why? Because a too-short chimney meant the system had a history of inadequate draft, sooting, backpressure, puffbacks, and loss of heat. This "fix" was a band-aid that kept the system running longer between (frequent) service calls, but at the expense of higher heating bills and wasted fuel.
We could have addressed this short chimney with a draft inducer fan, but a taller flue would be smart anyway, to get the chimney top higher than the roof surface. We discuss examples of extending chimney height to improve draft, performance, and fire safety separately
Just how short is "too short" for a chimney is a problem along with roof clearance requirements discussed at Chimney Height & Clearance
See BOILER OPERATING STEPS, 39 steps in how a heating boiler works. The following oil burner noise clues are taken from our more complete article:
Also see COMPLETE COMBUSTION, STOICHIOMETRIC for an explanation of complete fuel combustion and boiler or furnace maximum efficiency.
The basic measurements made by any competent oil heat service technician include the stack temperature, draft, smoke level, and carbon dioxide level. These data tell us whether or not the equipment is properly adjusted and operating safely and economically.
One of these most basic tests performed by an oil heat service technician is the "smoke test" using a strip of filter paper and a pump to sample the oil burner exhaust, measuring the level of smoke in the exhaust.
Details of how to measure the oil burner smoke level, a key measure used in setting the combustion air level, are now
Our photo (above left) shows a traditional smoke testing pump (the black cylinder with a handle at its right end) used for decades. This equipment was produced by Bachrach, an oil burner test equipment manufacturer.
The second common test performed by an oil heat technician evaluates the oil burner efficiency by measuring the carbon dioxide level or CO2 level in the oil burner exhaust. While there are electronic sensors used by some technicians for this purpose, many oil heat service tech's continue to use the time-tested Bachrach Fyrite™ oil burner tester.
Details of measuring the carbon dioxide level for oil burners, a second key measurement needed for proper setting of oil burner combustion air & operating temperature are now
We look for obvious trouble signs before making any changes or adjustments to the oil burner assembly by turning off power to the equipment, shutting off the oil supply line at the closest service valve, and opening the oil burner for inspection.
Our sketch (left) shows how an oil burner gun atomizes and sprays heating oil into the combustion chamber
Most oil burners are opened by loosening two screw clamps at the front of the transformer box mounted atop the oil burner tube and folding the hinged transformer back to expose the interior of the tube, the oil burner nozzle assembly, and other parts. Some obvious trouble signs inside the oil burner include:
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Readers needing an approach to heating system inspections that assures thoroughness, should also
Continue reading at OIL BURNER SMOKE TEST or select a topic from the More Reading links shown below.
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Frequently Asked Questions (FAQs)
Question: my oil burner shuts down after just a few seconds
My oil burner will come on for a few seconds and then shut down. I have changed the control, and the cad cell. If I disconnect the cad cell start the burner and allow it to run for about 10 or 15 seconds and reconnect the cad cell it will usually continue running until the water is hot. Sometimes the burner will operate normally for a period of time.
If it sets overnight when heat is called for it will shut down after it starts as if it has no flame. I know the fire is there because I can hear it burning. If I connect my multi-meter to the cad cell the resistance goes from very high to about 400-500 ohms. The only thing I haven't done is check the cut-off solenoid because I don't know how. Thank you for any help you can give me. - R.M. 2/25/2014
Reply: try this oil burner diagnostic flowchart
A competent onsite inspection by an expert usually finds additional clues that would permit a more accurate, complete, and authoritative answer than we can give by email alone. You will find additional depth and detail in articles at our website.
That said, try this diagnostic routine to see if that helps. OIL BURNER WONT RUN - Diagnostic Steps - what to check in what order
(Oct 16, 2012) tim said:
how do i locate the nozzles and ingnitor on a beckett unit
(Oct 24, 2012) John said:
please give me some advice regarding basic operation of VJP-140 gun type Volcano steam boilers. basic firing procedures, maintenance..thank you so much..please email me firstname.lastname@example.org
(Nov 7, 2012) Ken & Eliz said:
I have been told that there is a pinhole in my rear breech of my riello furnance and that this means my furnace is condemned and needs to be replaced ASAP. The rest of the furnace is in really good condition and we suspect that poor yearly cleanings (cleanings were only 1 hr for a 3-4 hr job) was the culprit. Can the breech be repaired? Is this a reason for immediate replacement? Are there licensed companies that do this type of repair? Thanks!
Ken & Eliz
I'm afraid to second-guess an onsite service expert where heating equipment safety is involved, but I can offer a few thoughts:
1. Repairability depends on a few things like: what is the nature of the hole and what caused it - for example a pinhole caused by corrosion is often the tip of an iceberg so to speak - and actually a much larger defect is looming, whereas a manufacturing defect may be covered under warranty and/or very small and possibly repairable.
2. in my experience, while it is technically possible to weld a small hole in perforated sheet metal, an issue is that NOBODY will sign off warranting the safety of the result - even if in their secret heart of hearts they think it's fine, no one wants the risk; and of course a technical expert might argue at a later failure that the heat stress of welding contributed to a future failure, hazard or event
If you are not convinced (by say having the service tech or manager show you and explain to you the problem) I would
- ask to see the exact location and nature of the hole, and ask an opinion about its cause and about the risk of similar defects not so easily found
- if what's there is a true pinhole (1/8" diameter or less) and you want to even consider some sort of repair, contact Riello directly, ask to speak with a technical service rep, ask for and then follow their advice.
Reader followup: (Nov 7, 2012) Ken & Eliz said:
DanJoeFriedman -- thank you very, very much for the info.
Reply: OK Ken & E:
watch out that corrosion means welding is not just a pinhole problem.
It's worth trying a patch by your service tech.
BUT WATCH OUT
be sure your smoke and CO detectors are working and installed in the right location
(Nov 8, 2012) levi said:
why is there oil coming out the bottom of the oil burner
If oil drips out of the rear of your oil burner most likelynthe fuel unit is not shutting off cleanly, letting unburned oil drip at the nozzle. An oil line leak can also be at fault. Both of these are operating problems that can lead to loss of heat or to an ugly oil burner puffback. It's time for a service call.
Drainage from the oil burner bottom weep opening may indicate a failing transformer or a leak the nozzle adapter, tube, or a dirty nozzle
(Nov 8, 2012) Art said:
Oil furnace trips out When reset it will run for about 10+ min. then it trips out again, little or no heat enters home.Also dark gray/black smoke comes from chimney,Also the metal exhaust from furmace is barely warm. I need help.it's getting cold Thanks.
Art, there could be any of several problems but at the least it sounds as if your system needs a thorough cleaning, oil noaale and filter and fuel unit changeout, and tuneup.
(Nov 9, 2012) Paul said:
I came home from work yesterday and discovered my Beckett AFG blower motor running with the burner not firing. I had to manually shut the system down. Primary did not trip. Turned power back on and the electric motor fired right up again and still no fire up or safety trip - killed power to the unit to stop. Is my primary bad?
DO NOT fire the oil burner before an expert replaces a bad primary control or finds and fixes a shorted wire or wiring error and
Inspects and perhaps cleans out excess oil pumped into the combustion chamber.
Otherwise there risk of a fire or puffback explosion on first ignition.
(Nov 10, 2012) Paul said:
DanJoeFriedman-thank you for your reply. Iv'e been troubleshooting this blower ever since, perhaps you can advise? I opened the door to the combustion chamber and cleaned up the excess fuel oil, changed the filter, strainer, and nozzle. I also checked the spark on the transformer with a screwdriver and I have a strong steady spark. I didn't disturb any of the settings as the boiler was running fine previously. I don't understand why the blower won't fire up - power seems to be getting to the transformer from the primary. Beckett AFG, Honeywell R4184D 1027 primary.
(Nov 10, 2012) Paul said:
Problem solved - I just replaced the primary control, now my boiler is running as smooth as ever!
(Nov 20, 2012) patrick email@example.com said:
i have a beckett furnance its about 10 years old, for the past 2 summers the heat turn on in the summer time, the only way to start the heat is through the emergency control. thermostat has been change and it still will not fired with the emergency switch to control on and off. what is the problem please reply.
Try going through the
Oil burner wont run, diagnostic steps
Just above in this article. I'm so sorry but your question just doesn't give me a better suggestion to go on
(Nov 26, 2012) Dave said:
Oil burner does not what to fire up
Start by checking for power
(Nov 26, 2012) Anonymous said:
just changed oil tank put 75.00 of oil in tank , turned on valve at tank , turned on shut-off switch and it won't start light for reset is flashingheldit in for 5 seconds still nothing
(Dec 1, 2012) bruce said:
oil burner with water heater is using more water than normal, adding water daily, do have more people using hot water than in the past. Do not see any leaks from radiators...this is a steam boiler
(Dec 6, 2012) winfield said:
On Wayne EH Oil Burners they have two blower wheels that will fit, 6.25" amd 5.25"
(Dec 7, 2012) bob windsor said:
Burner does not always come on when thermostat calls for heat. There is adequate fuel supply. All wires check out and are secure. Eye is clear. Every time button is pushed burner comes on and it recycles properly. Problem is intermittent and sporatic.
About diagnosing an oil burner that intermittenly won't "come on" - we need to distinguish between motor runs but we don't get oil ignition - and the burner goes off on reset, or the motor doesn't run at all.
The former means there is an ignition problem, perhaps a clogged nozzle or oil filter or a failing ignition transformer etc.
The latter is a thermostat or electrical problem.
About an increase in water consumption by a steam boiler
Steam boilers consume water normally.
Winfield, the size of the oil burner blower wheel is usually matched to the GPH firing range of the burner assembly. If you are replacing one use the same size as what you are replacing.
(Dec 7, 2012) winfield said:
The problem is the wheel was missing, so I would like to know wich one is correct for certain GPH firing ranges.
Thanks for the clarification.
Try measuring the space into which the blower fan will fit. It may be that only the smaller would fit, closing the question.
Or note the oil burner brand and model, and note either the actual nozzle size in GPH, or the firing range in GPH noted on the boiler data tag. With that info we can check with the manufacturer.
(Jan 4, 2013) Scott said:
Have an issue where my Beckett oil furnace will lock out. Hit the reset on primary controller and it fires right up. Sometimes it will run a while, others it will lock out again in a couple of minutes. Cleaned the CAD cell (though it didnt appear to need it) and still intermittently tripping the reset. Plenty of fuel and definitely getting electricity. Any suggestions?
(Jan 11, 2013) jose netto said:
my heat oil is not fired up some does but when i close the door is not work again why? what i have to do?
(Feb 18, 2013) Anonymous said:
my boiler takes to long to cut in even when its very cold outside,what should i check? and do you know of a good oil burner school in (Westchester NY or close to zip 10553
(Jan 31, 2014) Dennis said:
My Beckett AFG is sluggish when it is turning on but kick on fine and throws good heat. Any first step procedures? Thanks in advance.
Sluggish start up sounds like the oil burner needs cleaning and adjustment.
I would schedule a heating service call now - before the problem leads to loss of heat.
Service steps include standard items like oil change, screen change, nozzle change, cleaning and adjustment of the nozzle assembly - if those standard procedures don't fix the problem we'd dig deeper, checking pump pressure, bearings, shaft couplings &c.
(Feb 1, 2014) Dennis said:
First time I tackled the fuel side of the furnace and replaced the nozzle and did some basic cleaning and all seems well. I also changed the filter which I failed to do last year.
Excellent. Sounds as if the start-up problem on the oil burner was a typical response to needing a cleaning. Nice going.
(Feb 20, 2014) Dan said:
The only way my Williamson oil burner will ignite is by "jump starting" the thermostat wires on the Honeywell R8184G4009 box. When I want to shut the oil burner off all I have to do is remove the "jump start" wire. I just now replaced the upstairs wall mounted thermostat control. After I had the new wall mounted thermostat box wired and set up I turned the breaker box switch back on for the furnace. The oil burner did its usual start up but did not ignite. The red light came back on and the reset button popped back up on the Honeywell R8184G4009 box. I'm thinking about "jump starting" the furnace again and let it run for a couple of hours tonight. The oil burner is an older Williamson from the 1980's, prior to their bankruptcy I think. Do I need a new Honeywell R8184G4009 box?
Dan I understand your reasoning, but don't recommend forcing the system to run.
When the oil burner has shut down on "safety" and the reset button pops up on the primary control, it's ok to push that reset button ONCE to see if the system will start and keep running - that will let you have heat while you wait for the service technician to show up.
But do not keep resetting and running the system - doing so is unsafe and risks a puffback.
And do not assume that the problem is the control aquastat - the R8184G. It could be simply that the oil burner needs cleaning. Or there could be another service problem = even a clogged filter.
(Feb 21, 2014) Dan said:
I understand about the risks pushing that reset button more than once and how it will fill the chamber with fuel if it fails to ignite. I also understand the risks of "jump starting" or forcing the system to run, it was a last resort option to get some heat in the house.
Anyways just today my brother and I bought and installed a new Honeywell R8184G4009 box, so along with the new wall mounted thermostat control the system is working again. My brother also regapped the electrodes on the gun assembly to some measurements we found online. The gun assembly needs new electrodes, sounds like a to do project when the weather gets warmer.
I forgot to mention that a service tech did come out last month and replaced the nozzle on the gun assembly. Just the other day another guy came out and cleaned the fuel lines to and from the fuel pump. He also tested the photo lens/cad cell light sensor (you know what I'm referring to) and it is working properly.
This colder than normal winter forced me to learn alot about oil burners in the past month. I also found a sticker on the furnace with a written service log on it from the local heating company who installed the furnace back in 1988. I will be making my own maintainence log mounted on a clipboard to place by the furnace. Thanks for taking the time respond to my comment~Dan
Thanks for the feedback Dan. It will surely assist other readers.
Sorry I couldn't be smarter with the text exchange; the on-site person is always the most critical eye.
If you have time it would be useful to hear what you think was wrong with the primary control that you replaced, and more, if you kept the old box, it might be instructive to take a close look at it - nothing technical, just a look-see for obvious damage like burning marks indicating overheating of a relay or circuit board or wire contact.
(Mar 5, 2014) Correct Electrode and spray nozzle? Marco said:
I have an approximately 30 year old RUUD oil fired furnace (mod. # UOBC-112QAGA) with a Beckett AFG burner unit.
The problem I have is that for years I don't get a clean burn (appears to run rich with lots of build up on the spray nozzle until it clogs.)
My question: how do I know I have the right Electrode and/or Nozzle?
The oil burner instruction booklet or the manufacturer will tell you what electrodes are standard. These are field replaceable parts but they do vary in length, diameter, and angle bend.mand of course you want the gap correct. Also, The transformer could be bad, or system could be not adjusted properly, or combustion air inadequate, etc.
E.g. Backpressure can overheat and destroy even a new transformer.
(July 5, 2014) Dave said:
My Wayne Msr Oil burner. Starts with a strong flame runs sometimes 20 seconds sometimes a minute or two then it sputters and the flame cuts in and out and then it shuts down. Sometimes with out touching anything the oil burner will start back up with a strong flame and run until it sputters and dies again?
Check for a clogged oil line or filter
Question: where to find heating oil service mechanics in Northern Ireland
Heating Oil said:
It’s a good blog about Oil burners and their repairs but I was looking for a mechanic for my machine of heating Oil in Northern Ireland.
Here are some excellent sources for heating & chimney service and repair experts in Northern Ireland
Northern Ireland Association of Chimney Sweeps, NIACS, www.niacs.co.uk
Northern Ireland Warm Homes Scheme, www.nihe.gov.uk/index/benefits/grant_assistance.htm The Warm Homes Scheme provides a free service to all applicants to ensure that you are receiving all the benefits that you are entitled to. NOTICE: As the Scheme is due to end on 31 March 2015, it is important that you apply as soon as possible to check if you are eligible
SNIPF: Scottish and Northern Ireland Plumbing Employers Federation http://www.snipef.org/
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