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AFUE DEFINITION, RATINGS
AGE of CHIMNEYS & FIREPLACES
AGE of AIR CONDITIONERS & HEAT PUMPS
AGE of HEATERS, BOILERS, FURNACES
AGE of WATER HEATERS
AIR CONDITIONING & HEAT PUMP SYSTEMS
AIR FILTERS for HVAC SYSTEMS
AIR FLOW MEASUREMENT CFM
AIR HANDLER / BLOWER UNITS
AIRBOUND HEAT SYSTEM REPAIR by WATER FEED VALVE
ANODES & DIP TUBES on WATER HEATERS
ANTIFREEZE for BOILERS
ANTI SCALD VALVES
APPLIANCE DIAGNOSIS & REPAIR
APPLIANCE EFFICIENCY RATINGS
ASBESTOS IDENTIFICATION IN buildings
BACKDRAFTING HEATING EQUIPMENT
BACKFLOW PREVENTER VALVE, HEATING SYS
BACKFLOW PREVENTER, HEATER WATER FEEDER
BACKUP HEAT for HEAT PUMPS
BIOGAS PRODUCTION & USE
BLOWER FAN CONTINUOUS OPERATION
BLOWER FAN OPERATION & TESTING
BLUE vs YELLOW COMBUSTION FLAMES
BOILER CHEMICAL TREATMENTS
BOILER COMPONENTS & PARTS
BOILER CONTROLS & SWITCHES
BOILER LEAKS CORROSION STAINS
BOILER LEAKS, HOW TO LOCATE
BOILER NOISE SMOKE ODORS
BOILER OPERATING PROBLEMS
BOILER OPERATING STEPS
BOILER PRESSURE & TEMPERATURE SETTINGS
CAPACITORS for HARD STARTING MOTORS
CARBON DIOXIDE - CO2
CARBON MONOXIDE - CO
CARBON MONOXIDE WARNING
CHIMNEY INSPECTION DIAGNOSIS REPAIR
CHIMNEYS & Flues - Asbestos Transite Pipe
COOL OFF HEAT, Thermostat Switch
COMBUSTION AIR for TIGHT buildings
COMBUSTION GASES & PARTICLE HAZARDS
COMBUSTION PRODUCTS & IAQ
COMPLETE COMBUSTION, Stoichiometric
CONDENSING BOILERS/FURNACES DAMAGE
CONVECTOR HEATERS - HYDRONIC COILS
CREOSOTE FIRE HAZARDS
Curved Brick Chimneys - Sulphation
DEFINITION of HEATING & COOLING TERMS
DIAGNOSTIC GUIDES A/C / HEAT PUMP
DIAGNOSE & FIX HEATING PROBLEMS-BOILER
DIAGNOSE & FIX HEATING PROBLEMS-FURNACE
DIRECT VENTS / SIDE WALL VENTS
DIRECTORY of OIL TANK EXPERTS
DRAFT HOODS - gas fired
DRAFT MEASUREMENT, CHIMNEYS & FLUES
DRAFT REGULATORS, DAMPERS, BOOSTERS
DUCT SYSTEM & DUCT DEFECTS
DUST, HVAC CONTAMINATION STUDY
DUST SAMPLING PROCEDURE
ELECTRIC MOTOR DIAGNOSTIC GUIDE
ELECTRIC MOTOR OVERLOAD RESET SWITCH
ELECTRICAL POWER SWITCH FOR HEAT
EVAPORATIVE COOLING SYSTEMS
FAN, AIR HANDLER BLOWER UNIT
FAN AUTO ON Thermostat Switch
FAN, COMPRESSOR/CONDENSER UNIT
FAN CONVECTOR HEATERS - HYDRONIC COILS
FAN LIMIT SWITCH
FILTERS, AIR for HVAC SYSTEMS
FILTERS, OIL on HEATING EQUIPMENT
FIRE SAFETY CONTROLS
FIREPLACES & HEARTHS
FLAME COLOR, BLUE vs YELLOW COMBUSTION
FLOODED HEATING EQUIPMENT REPAIR
FLOODED WATER HEATER REPAIR
FLUE VENT CONNECTORS
FREEZE-PROOF A BUILDING
FUEL OIL TYPES & CHARACTERISTICS
FUEL UNIT, HEATING OIL PUMPS
FURNACE CONTROLS & SWITCHES
FURNACE EFFICIENCY, HIGH vs MID
FURNACE HEAT EXCHANGER LEAKS
FURNACE OPERATION DETAILS
FURNACE OPERATING TEMPERATURES
GALVANIC SCALE & METAL CORROSION
GAS BURNER Flame & Noise Defects
GAS FIRED WATER HEATERS
GAS PIPING, VALVES, CONTROLS
GAUGES ON HEATING EQUIPMENT
GEOTHERMAL HEATING SYSTEMS
HEAT EXCHANGER LEAK TEST
HEAT LOSS in BUILDINGS
HEAT LOSS DETECTION TOOLS
HEAT LOSS INDICATORS
HEAT LOSS PREVENTION PRIORITIES
HEAT LOSS R U & K VALUE CALCULATION
HEAT TAPES & CABLES on Roofs for Ice Dams
HEATING COST FUEL & BTU Cost Table
HEATING COST SAVINGS METHODS
HEATING LOSS DIAGNOSIS-BOILERS
HEATING LOSS DIAGNOSIS-FURNACES
HEATING OIL CLOUD WAX GEL POINT
HEATING OIL EXPOSURE HAZARDS, LIMITS
HEATING OIL - OLD, USEABLE?
HEATING OIL PIPING TROUBLES
HEATING OIL SHELF LIFE
HEATING OIL SLUDGE
HEATING OIL USAGE RATE
HEATING SMALL LOADS
HEATING SYSTEM INSPECT DIAGNOSE REPAIR
HEATING SYSTEM INSPECTION DETAILS
HEATING SYSTEM NOISES
HEATING SYSTEM TYPES
HIGH EFFICIENCY BOILERS/FURNACES
HOT WATER HEATERS
HOT WATER IMPROVEMENT
INSULATION INSPECTION & IMPROVEMENT
LOW VOLTAGE BUILDING WIRING
LOW VOLTAGE TRANSFORMER TEST
GAS LP & NATURAL GAS SAFETY HAZARDS
MANUALS & PARTS GUIDES - HVAC
MIXING / ANTI-SCALD VALVES
MOTOR OVERLOAD RESET SWITCH
NATURAL GAS COMBUSTION PRODUCTS
NO HEAT - BOILER
NO HEAT - FURNACE
NOISE / SOUND DIAGNOSIS & CURE
NOISE AIR CONDITIONER / HEAT PUMP
NOISE, DUCT VIBRATION DAMPENERS
NOISE CONTROL for HEATING SYSTEMS
NOISE, PLUMBING CHECKLIST
NOISE, WATER HEATER
ODORS GASES SMELLS, DIAGNOSIS & CURE
ODORS FROM HEATING SYSTEMS
OIL BURNER FUEL UNIT
OIL BURNER INSPECTION & REPAIR
OIL BURNER NOISE SMOKE ODORS
OIL BURNER NOZZLE & ELECTRODES
OIL BURNERS, RETENTION HEAD
OIL BURNER SOOT & PUFFBACKS
OIL FILTERS on HEATING EQUIPMENT
OIL FILTER MISSING
OIL FUEL TYPES & CHARACTERISTICS
OIL HEAT FIRE SAFETY CONTROLS
OIL LINE CLOGGING FIX
OIL LINE QUICK STOP VALVES
OIL LINE SAFETY VALVES, OSVs
OIL FILL PIPE LEAKS
OIL PUMP FUEL UNIT
OIL SPILL CLEANUP / PREVENTION
PLASTIC Plexvent / Ultravent RECALL
PULSE COMBUSTION HEATERS
PRESSURE REDUCING VALVES
PUMPS, PONY PUMPS
RADIANT HEAT Floor Mistakes to Avoid
RADIANT HEAT TEMPERATURES
RADIANT SLAB FLOORING CHOICES
RADIANT SLAB TUBING & FLUID CHOICES
REFRIGERANTS & PIPING
RELIEF VALVE LEAKS
RELIEF VALVES - TP Valves on Boilers
RELIEF VALVES - Water Heaters
RELIEF VALVE LEAKS
RELIEF VALVES - TP Valves on Boilers
RELIEF VALVES - STEAM TP VALVES
RELIEF VALVES - Water Heaters
RELIEF VALVES - Water Tanks
Reset Switch - Heater Primary Control
Reset Switch Broken - Quick Repair
RESET SWITCH - ELECTRIC MOTOR
Reset Switch - Stack Relays
SAFETY HAZARDS & INSPECTIONS
SAFETY HAZARDS GUIDE
SAFETY, HEATING INSPECTION
SAFETY RECALLS CHIMNEYS VENTS HEATERS
SOLAR HEATING SYSTEM DESIGNS
SOLAR HOT WATER HEATERS
SOOT on OIL FIRED HEATING EQUIPMENT
SPILL SWITCHES - Flue Gas Detection
SPLIT SYSTEM AIR CONDITIONERS & HEAT PUMPS
STACK RELAY SWITCHES
STAIN DIAGNOSIS on BUILDING INTERIORS
STEAM HEATING SYSTEMS
Thermal Expansion Cracking of Brick
THERMAL EXPANSION of HOT WATER
THERMAL EXPANSION of MATERIALS
THERMAL IMAGING, THERMOGRAPHY
THERMAL IMAGING MOLD SCANS
THERMAL MASS in BUILDINGS
THERMAL TRACKING & HEAT LOSS
THERMOSTATS, HEATING / COOLING
TRANSITE PIPE CHIMNEYS & FLUES
VIDEO GUIDES: Heating System Videos
VIDEO GUIDES - InspectAPedia.com
WATER HEATER SAFETY
WATER HEATERS for HOME HEATING USE?
WATER HEATER NOISES
WATER HEATER SCALE - De-Liming Procedure
WATER HEATER SCALE PREVENTION
WINTERIZE A BUILDING
WOOD, COAL STOVES & FIREPLACES
WOOD STOVE SAFETY
ZONE VALVES, HEATING
Oil Burner Nozzle Electrodes: here we explain how to select & install an oil burner nozzle, we describe different oil burner nozzle firing rates & spray patterns; we discuss the setting of the gap and position of oil burner ignition electrodes, and we discuss how to diagnose oil burner electrodes or nozzle problems, how to inspect, clean, and adjust oil burner nozzles, electrodes, and air turbulators used on heating oil burners found on residential & light commercial oil burners.
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Oil Burner Nozzle Types, Flow Rates in GPH, Spray Patterns, Selection Guide
Oil burner nozzles have the job of spraying heating oil into the combustion chamber in a spray pattern of the right size and shape to properly fit the equipment and to assure a fine spray that in turn assures as complete combustion of the heating oil as possible. Oil burner nozzles get grubby during use, but actually they are a beautiful and precision-made and sophisticated device.
Cut to the chase? OK so if you don't know a reason to change, install the same oil burner nozzle type that was already on the burner.
Our oil burner nozzle photo at left shows you what an oil burner nozzle looks like. We are holding a Delavan 0.85 gph (oil flow rate) oil burner nozzle.
The "80A" marking on another nozzle facet (photo below left) defines the spray angle (80 degrees) and spray pattern (A). At the right side of the nozzle assembly you can see the sintered bronze filter that protects the oil burner nozzle orifice from clogging. But of course if oil reaching this point is dirty (say you never installed that oil filter or it's leaking debris), this final filter will clog.
Our third oil burner nozzle (below right) shows the outlet end of the nozzle and you can see that there is a stainless steel insert with a small opening that forms the spray pattern for this device. Before manufacturers started using these beautiful steel inserts the entire oil burner nozzle was made of brass - and the spray opening would wear during the heating season, leading to a bad spray pattern. This is not the case any longer and the nozzle below will have no wear problems provided it is replaced during annual maintenance.
First off a new nozzle is not expensive. Second using a wire in the nozzle orifice will likely damage it and ruin the spray pattern.
When the service company buys oil burner nozzles (in huge quantities in their case) each oil burner nozzle comes in a (usually color-coded) plastic container such as the one we show at left, indicating the gph rating and the nozzle angle and spray pattern.
The number of oil burner nozzle sizes and spray patterns is quite large because the nozzle properties have to accommodate not only models of oil burners themselves but more critically, different sizes and shapes of combustion chambers in boilers, furnaces, and water heaters, and different combustion chamber designs (wet base, dry base, for example).
You can find that in the installation and service manual for the oil fired device, you can ask the manufacturer, or you can use a nozzle guide such as the W.M. Steinen Mfg. Co. Nozzle guide - a book that lists literally thousands of oil burner nozzles for every application. We show an example page from Steinen at left. [Click to enlarge this or any image or photo found at InspectApedia.
You will see that for each brand of oil burner, or boiler, furnace, or water heater, and for each model within that brand, there is a listing of the required oil burner nozzle. These oil burner nozzle specifications will show:
This article series answers most questions about central hot water 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 of common heating system defects.
An oil burner adjustment template provided by Beckett Corporation and shown just below summarizes the adjustment of the ignition electrodes & their positioning for Beckett oil burners.
And for eight oil burner head designs the template recommends oil burner nozzle firing rates (in gallons per hour or gph) and spray pattern or style.
As you will read below, there is a very large array of oil burner nozzles and spray patterns provided by a variety of manufacturers.
Also see HEATING OIL USAGE RATE where we explain oil burner nozzles in additional detail.
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.
Readers should see HEATING SYSTEM INSPECTION PROCEDURE wHere we explain an organized approach to inspecting the entire heating system, beginning outdoors, continuing indoors, and ultimately in most detail in the boiler or furnace room.
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Frequently Asked Questions (FAQs)
Question: oil burner nozzle size and spray pattern changes
(Feb 23, 2013) steve said:
my oil nozzle colgged,it was a .60 70deg. the local store only had a .060 80deg. is this ok to use.. the furness fired right up,,, but i dont want to do any damage,, thank you
(Mar 18, 2013) Anonymous said:
What would happen if I use a 1.25 / 80 nozzle which my 40 yr old oil burner calls for, verses a 1.00 / 80. I trying to eliminate the short cycle and short time on which is the problem I've having now. Would adjusting my burner thermostat to the lower end of 0.2 or the higher of 1.4 help? As you can see I'm grasping at straws looking for an answer. Thank you.
(Jan 6, 2013) Nathan said:
Can I use 1.0 80A nozzel instead of 1.0 70A? How is it effect my oil heater?
Short burner on cycle time can indeed be due to a too-large nozzle, but it could be due to improper control settings, burner adjustments, or other snafus too.
Check the data tag on your furnace or boiler to see what the manufacturer says is the acceptable oil burner nozzle size range that is permitted for your equipment, then call a service technician who knows how to service and adjust the system properly.
Question: Every time my oil furnace fires I can smell raw heating oil/diesel smell from my chimney.
Every time my oil furnace fires I can smell raw heating oil/diesel smell from my chimney. It may last up to 5 minutes. No smell in the house. The furnace gets serviced every year,new filter,new nozzle and cleaned. - Joe. 10/10/11
Reply: Improper oil burner operation, unburned oil, or bad draft - watch out for a puffback
Most likely you've got a system that is not running properly and is stinking up things at start-up. Once strong draft is established and the system is up to full operating temperature (typically 5 minutes), the draft improves and combustion may improve enough to keep going. But the system is not running properly.
Question: Sometimes my oil burner won't re-ignite
I have an aero burner on my hot water furnace. Starts and runs perfect most of the time. Every once in a while it will not re-light I press the reset button, it might run perfect for a week or two, then one day it will not light Press button again,starts right up and runs perfect, maybe for two days or two weeks again, then all of a sudden it will not light Any suggestions what to look for. - Joe Daye 12/3/11
Joe, take a look at the oil burner diagnostic suggestions beginning at OIL BURNER INSPECTION & REPAIR. Usually when a system is limping along as yours is described, the operating problem is going to get worse. I'd look for an air leak in the oil piping, a dirty oil burner, a clogging filter, a draft problem.
Question: I kept my oil furnace running for two hours - would that damage the electrodes or transformer?
I kept the oil furnace running continuous for about two hours, then it stopped running by itself. I pushed the reset on the stack control, it ran for a few seconds then kicked off. Did I burn out the electrodes or transformer by running it non stop? - Bob 2/9/12
Question: In cleaning my oil burner assembly I bumped the electrodes - I'm not sure if there is a problem
I cleaned my nozzle and bumped my electrodes but I think I got them set back where they go. I put them back in. I started my furnace and now it runs fine. It runs till it gets to proper set thermostat setting then kicks off. The relay control cell seems a little hot at the back closest to furnace. I checked to see if working properly by pushing red switch when running and when pushed down it stops and let up it continues.
Is this normal the heat at back of gray box? Also could you do damage if your electrodes are a hair off? I don't know I am just paranoid now! The flame constantly runs with motor till it heats to proper temperature then kicks off. - Mark Freed 2/20/12
If there is an oil burner adjustment or cleaning or draft problem, one result could be back pressure in the combustion chamber. The oil burner may start and run, but back pressure sends heat back up the burner tube where it can overheat (and destroy) the ignition transformer and it may also heat up the primary or cad cell control mounted on the same assembly.
If the electrodes are a "hair" off - that would be about 25 to 50 microns, and not important. But if the electrodes are more than 1/16" off of proper position (see the Beckett template above), or if the ignition transformer is failing, adjustment and replacement may be in order.
(Jan 20, 2013) Mark said:
25 to 50 microns? Don't you mean 25 to 50 thousands of an inch? Good grief - 50 microns is slightly less than 0.002". No one, not even the factory, is going to be able to adjust the electrodes with that kind of tolerance!
Right Mark. As I said a "hair off" - a human hair is about 25-50 microns in diameter. The point is that being "a hair off" would not explain electrode malfunction.
Question: Our oil burner only ignites if the door is open. What might be wrong.
We have replaced the electrodes and nozzle on the furnace. It will only light with the door open and stay going after you close the door - seems like it is not getting enough air. What could be the problem? - Simone
If you mean that the door to the boiler room (or furnace room) has to be open for an oil burner to work, that suggests it's air starved - we need about 1 sq. in. of air intake into a small utility room per 1000 BTUH for oil fired heating equipment - so a 90,000 BTUH oil heater would need 90 sq. in. of unfettered air intake opening. If you add louvers and screening the sq. in. requirement is increased. Take a look at COMBUSTION AIR and COMBUSTION AIR for TIGHT buildings
But lack of combustion air usually leads to sooty operation and the oil burner going off on reset, or worse, loss of heat.
The bit about "... stay going after you close the door " is baffling. If we don't have enough combustion air to ignite then we shouldn't have enough combustion air to keep going. I figure you need a service call from an expert heating service tech who will check the condition of the burner, combustion air setting, cleanliness of the flue vent connector and chimney, the draft, and a few other parameters.
Question: oil burner electrode gap, weak spark, questionable transformer
4/7/2014 FRED said:
FranceFormer 5lay-03...I had to reduce my electrode gap below specks to get an ignition on Wayne MSR-C burner...shorting transformer terminals with insulated screwdriver yielded a spark of less than 1/4...Is this a sign of a failing 10,000 volt transformer... or is the output an all or none deal? BURNER SEEMS TO BE WORKING FINE.
It sounds as if your transformer is bad. I'd replace it.
Watch out: backpressure in the combustion chamber can cause heat to back up the combustion tube and cook the transformer. A clue would be oil leaking out of the component.
Assuming we've got voltage to the transformer, other causes of weak spark between electrodes include
- cracked ceramic insulators and shorting out of the current to the oil burner metal body
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