Photograph of  a modern oil-fired heating boilerFixing an Oil Burner that Won't Run
Oil burner no-start diagnostic FAQs

  • POST a QUESTION or READ FAQs about oil burner inspection, diagnosis, & repair, troubleshooting procedure, how to get the oil burner running again, best order of diagnostic steps.

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Q&A on why an oil burner won't start or won't keep running:

Frequently-asked questions and answers about why an oil burner will not start or will not keep running when it should.

These oil burners are used on heating boilers, furnaces, water heaters and some other heating appliances.

This article series escribes how to recognize common oil-fired heating appliance operating or safety defects, and how to save money on home heating costs

We also provide a MASTER INDEX to this topic, or you can try the page top or bottom SEARCH BOX as a quick way to find information you need.

Oil Burner Won't Run: Diagnostic Steps - what to check in what order

Oil burner schematic (C) Carson Dunlop AssociatesThis article series explains the inspection, diagnosis, & repair of oil burners used in heating appliances such as hot water boilers, steam boilers, & water heaters.

These questions about troubleshooting oil burners were posted originally at OIL BURNER WONT RUN - you definitely want to review the diagnostic suggestions given there.

If your heat is not working properly, and the problem does not seem to be the oil burner itself, see NO HEAT - BOILER - hot water or steam heat

or see NO HEAT - FURNACE - forced warm air heat

On 2016-12-30 by (mod) re: draft regulator door keeps banging


If by "flapper" you mean the draft regulator in the flue vent connector between heater top and chimney, then it sounds as if there is a burner operating problem; flickering electric means there's an unsafe condition in the electrical system - perhaps a shorting wire or control at the heater.

You want to TURN OFF the equipment and call for emergency repair.

Keep me posted.

On 2016-12-30 by Linda

When the heater kicks on the flapper keeps clapping to the point that it seems like it's gonna choke out and electric flickers in the house

On 2016-12-28 by (mod) re: loose or bad electrical connections on an oil burner


I'd look for a loose or corroded electrical connection in the thermostat wiring and furnace heater control wiring.

If your heat is hot water ( boiler not furnace) I'd also look for poor thermal contact at the temperature sensor)

On 2016-12-28 by Eric

My furnace runs fine 98% of the time, but once in a while, the thermostat kicks on, but does not turn furnace on. I checked all wires, and replaced thermostat. Still does it. Please help!

On 2016-12-21 by (mod) re: ask the oil heat service company for an expert


I'd call the service manager and politely ask for a senior, experienced service tech to diagnose what has gone wrong.

On 2016-12-21 by Reuben A. Larson

Our furnace was working fine until we had it cleaned. Now it runs fine for about 6 hours and then it shuts down. Furnace repair person has put on a new cycle controller but it still shuts down after 6 hours. What do I do now ?

On 2016-12-20 by (mod) re: don't keep replacing parts on the oil burner that keeps going off on RESET

Before replacing parts arbitrarily I'd prefer to call an oil heat service tech. There could be any of several problems but a system that keeps going off is also potentially unsafe, risking a puffback explosion.

On 2016-12-20 by ekj06

I'm having to hit the relight button on my oil forced-air furnace every couple of days. I replaced the igniter a couple of years ago. Maybe a relay now?

On 2016-12-20 by (mod) re: oil burner won't keep running, shuts down and needs the reset button

Sounds like cleaning or repair to a nozzle, filter, screen, electrode etc. is needed. DO not keep pressing the reset button or you risk a puffback explosion. Search for OIL BURNER PUFFBACK EXPLOSION to read details

On 2016-12-18 by Gary

I hit the reset button on my oil furnace it will come up to temp called for it shuts down the when temp drops and heat is called for again it will fire up then shut right down. Any ideas?

On 2016-12-16 by Anonymous

My oil furnace keeps shutting off after 5 min...
Can you healp please

On 2016-12-16 by Fred thompso n

Carlin primary code latchup

On 2016-12-16 by Jennifer

My oil furnace has been running fine but we run out of oil my husband bled the line hit the reset button it come on went back off done this twice but won't come back on what do we need to do

On 2016-12-15 by scott

my oil furnace comes on heats when called to,,heats up to temp called for but after burner is off the blower never shuts off???it cuntinually runs ...

On 2016-12-13 by (mod)


Let's start by going down the diagnostic list at OIL BURNER WONT RUN


On 2016-12-13 by (mod)

AUTHOR:Gola (no email)
COMMENT:We have replaced oil pump to our burner but continue to have to press reset to start sometimes and it will cut off after starting sometimes what is problem?

On 2016-12-11 by (mod)

It sounds to me like a wiring or a control error. However if the motor homeless and is tripping a reset button then the problem could be a seized motor or a seized fuel unit that the motor cannot turn.

On 2016-12-11 by Peanuts

Have changed all components,igniter,fuel pump, control box. Motor will not come on. I have checked the motor and it runs smooth and quite. Will not start while installed on boiler. What's up with it?

On 2016-12-09 by (mod) re: Beckett oil burner won't start


To debug I'd scan the suggestions in the article OIL BURNER WONT RUN. It'd be helpful to know more about what happens: in particular, when the TT calls for heat, does the oil burner not run at all? Or does it run but the burner doesn't ignite?

If the latter, do not keep re-starting the burner as you risk a PUFFBACK EXPLOSION (Search InspectApedia for that term for details).

If the former, could be a loose wire, bad control, or a motor that's seizing up or overheating and shutting off on thermal reset.

On 2016-12-08 by jimdreg

My Beckett oil burner won't start when the thermostat calls for heat 'some' of the time. Every once in awhile I have to turn the power switch to it off and on a couple times to make it start. I replaced the Intermittent Ignition Oil Primary unit but that made no difference. What is causing this?

On 2016-12-06 by Anonymous

Why does igniter on becket burner bridge with gunk

On 2016-12-06 13:00:13.940354 by derek

there is a mix between water and oil squirting from the right hand side of the burner? is this dangerous

On 2016-12-05 18:45:00.357900 by Mark

The wind goes down the chimney, and shuts the burner down, causes?? fixs??

On 2016-12-01 by Anonymous

Oil burner lights stays on for approx 4hrs then goes into lockout

On 2016-11-23 by Matt

I have a Smith oil burner. The burner shuts off at the aquastat high temp but the temp and pressure continue to rise.

On 2016-11-22 by (mod) re: furnace won't re-start and no red or green lights show. and re: oil leaks at the oil burner

Sounds like a tripped breaker or blown fuse, Anon.

TJ: your fuel system is leaking and spraying fuel inside of the oil burner gun. THIS IS UNSAFE and risks a puffback explosion. It needs expert repair. I suspect damaged threads or a loose connection in the gun assembly. Turn off the system and call for repair.

On 2016-11-22 by Anonymous

Furence shut off wont start no red or greene light on reset

On 2016-11-16 by Tj

I have a Beckett forced hot air furnace and fuel is coming out off the ignition box? Just put new nossell in. Why would it do that

On 2016-11-11 by Daniel

Becket burner - boiler has shut off several times over the past week , but starts right up after the reset button is pushed

On 2016-10-20 by (mod) re: Circulator pumps run but boiler wont' heat up


If your New Yorker boiler turns on when there is a call for domestic hot water (at plumbing fixtures) then it's supporting a tankless coil (or an indirect fired water heater) and we know that the boiler itself works.

Now if the burner does not turn on when there is a call for heat, that could be because the boiler water is already hot enough that the primary control is not turning on the burner.

Feel the outlet piping from the boiler and check the circultor(s) to see if hot water is circulating. If not, that is if the circulator doesn't run or if the circulator runs and the water is cold, then the primary control or its sensor are probably faulty.

On 2016-10-20 by Joe

I have a New Yorker furnace oil hot water it comes on when hot water is turn on and needed . But when you turn on thermostat for heat (three zones ) there circulator comes on but the furnace does not turn on to heat up .

Changed the control box put a new one it turned on for few seconds then shut off . still have same problem . Circulator comes on but does not turn on furnace shut off all thermostats circulators shut off . Could you tell me what the problem could be

On 2016-10-12 by Bobby Wells

I have a oil birner furnace and it kicks on but wont ignite. Then shuts off after a min. Or so. I forgot to shut the valv

n the tank when I had it filled. Mine burns diesel. Well not knowing, all the fuel leaked out of the unit . Now it wont fire up.......

On 2016-10-01 by Donald

OilBurner won't start

On 2016-08-28 by (mod) re: dirty oil burner nozzle causes system to go off on RESET

THe most common reason that an oil burner goes off on reset is a dirty or clogged nozzle assembly.

Another common problem is air leaks in the oil piping.

On 2016-08-28 by Rick

For a oil hot water heater,After pushing re-start red button,ignition runs for a few seconds and stops.Would the problen most likely be th eHoneywell controller or dirty nozzles?

On 2016-07-02 by (mod) re: bad ceramic insulators on the oil burner nozzle assembly

I see that problem when the ceramic insulators are shot, the electrodes are dirty and shorting, the contacts between transformer and electrode rod back ends are poor, or the transformer is shot.

On 2016-07-02 by Anonymous

spark not reaching the top of electrodes

On 2016-06-25 by (mod) re: no spark visible at the oil burner electrode assembly

Certainly; if you don't see a spark between the igniters and the head is clean, not shorted out, and the unit has power, then that's a good guess.

On 2016-06-25 by Dave

I have a Wiel Mclain oil burner. It's getting fuel,the motor is running but it doesn't ignite.I can hear it click,but it won't ignite. Could this be the ignition transformer?

On 2016-04-26 by Davidc

Have one 2 pipe if it sits they have to reset does not do this every time I try to catch it

On 2016-04-24 by craig

Looking at the electrodes through a Crack I can see what appear
s to be a bright misfire of some sort,,,THIS IGNITION problem coupled with lncomplete combustion is causing a shutdonw..whatsup..

On 2016-03-14 by (mod) re: noisy oil burner startup


You may have a combustion air problem, the wrong nozzle pattern or size, or another mis-adjustment. Unfortunately it's no longer possible to properly set up an oil burner by eye and spit - a bit of training and use of CO2, stack temperature, and smoke measurements are also needed.

On 2016-03-13 by todd

burner rumbles on initial firing then quiets down. i have a new nozzle and filed electrodes to a sharp point and adjusted .

On 2016-02-25 by John scifo

After reseting it runs reaches desired temp & turns off normal hav to reset before it turns back on

On 2016-02-21 by (mod) re: check oil burner fuel unit output pressure / flow

a service tech would probably check for pump output on the burner side

On 2016-02-21 by Peter

Air in fuel line. Every few days.
Plenty of fuel in tank. No water just air.
Could it be the pump, 10yrs old?

On 2016-02-16 by (mod) re: seized oil burner fuel unit (oil pump)

Sounds like a seized or failed fuel unit. The burner should be going off on reset.

On 2016-02-16 by Anonymous

I have a fuel oil furnace that won't do anything it has high and low voltage at primary control, have jupered r and w still don't run have individual tested components all good solenoid valve has small amount of fuel leaking around shaft what can I do next?

On 2016-02-15 by (mod) re: possible bad oil burner control

That sounds like a bad control. Before replacing it, turn power off to the heater, wait a couple of minutes and turn it back on. Try once more.

On 2016-02-15 by Robbie

Thanks for the feedback, yes I left it sit and turned the power off to it for 6 hours came back turned the power on still locked out, pushed and held reset for over 1 minute still just keeps flashing, I'm going to get a new primary control as soon as possible and replace it and see if that helps, I have a R8184G 4009 I might hook up and see if it works because it'll be a week before I can get a new R7184B or I'm some place I can get someone on to look at it, thanks

On 2016-02-14 by (mod) re: oil burner reset button won't re-set

Good question Robbie. My answer is ... as my mentor Mark Cramer (Tampa FL home inspector / educator) says: ... it depends.

When a primary control trips off on reset, if you depress the re-set button rather quickly (say a minute or two) after it has tripped, it may not re-set. Depending on the particular control's design it may need to be off and left alone 5-10 minutes, as some controls include a thermal device that heats up to cause the tripping, and it has to cool.

If after a good wait - say 10 minutes or longer - the control won't reset then something else is wrong.

Watch out: don't keep pressing the reset button. If you press it and it resets and the burner runs for 10-20 minutes or longer you can have heat while waiting for the repair technician. But if the burner tries to start but trips off on reset quickly, you're sending unburned oil into the combustion chamber. Light that off after a few button presses and restart attempts and you could cause a dangerous puffback explosion.

Search Inspectapedia for PUFFBACK EXPLOSION to read details.

On 2016-02-14 by Robbie

Have a question, my R7184B will not reset, if u hold the reset button for 1 minutes 5 minutes however long it won't reset, sounds like to me it's gone bad because it should atleast reset and then if there's a problem lockout again right, but since it won't reset at all its probably gone bad??

On 2016-02-08 by (mod) re: I hit the oil burner reset button three times and now it won't start


You need to call for professional repair. DO NOT KEEP PRESSING THE RESET BUTTON as you risk a puffback explosion.

On 2016-02-08 by Julie

Hit the reset button three times and it came on but now will not come on at all only makes a click sound

On 2016-01-24 by (mod) re: oil burner goes off on reset once a day

I would call for repair - any of several problems could be the cause but the risk is ultimately loss of heat or a puffback explosion.

On 2016-01-19 by Tom Greco

Oilburner shuts off on its own once every day have to keep turning it back on every day

On 2016-01-17 by Dee

My furnace starts up then stops. I have to press the reset button every time I want heat. Help me fix this it's getting cold.

On 2016-01-09 by (mod) re: suttering starts at the oil burner

I've seen complaints about on-off stuttering starts with oil burners before, usually traced to either a loose wire or a failing control.

On 2016-01-09 by Bruce

We were having a problem with the furnace which was that upon startup, it would click off and on again in rapid succession, and after doing that, I'm guessing about 6 or 8 times, it would then stay on. It didn't do this every time, but seemed more apt to do it when it had been off for several hours, particularly in the morning. I believe it did this for at least 2 or three weeks, and seemed to be getting worse.

We finally made an appointment to have it looked at, and two days before the appointment, the problem vanished (we cancelled the apt.). It has been fine now for about two weeks. We are under no illusion that it has fixed itself, so expect the problem will come back sooner or later. Any idea on what could have caused that, and how the problem could just disappear (even if temporarily) on its own? It's rather bizarre.

On 2015-12-30 by (mod) re: compare oil burner temperature with aquastat settings

Check the boiler temperature and pressure when the boiler turns on - compare those to the aquastat settings; the low limit may be turning on the boiler for a tankless coil;

On 2015-12-30 by Jeremy

It is a forced air furnace. I will check thermostat wires. Any other ideas of forced air fuel oil furnace?

On 2015-12-28 by (mod) re: oil furnace comes on even when room temperature is above the thermostat setting


A failing control, temperature sensor at the boiler, or even shorting thermostat wires can cause intermittent boiler operation, as can troubles at the circulator pumps (see )

The things you repaired are good to do but don't address the controls for the system.

Running a few times an hour sounds excessive tome. I'd start by reviewing the aquastat settings (see AQUASTAT SETTINGS at found via search of our site)

On 2015-12-23 by Jeremy

My fuel oil furnace works with thermostat but will come on even when temp is above the setting. The burner and pump run for 60 seconds a few times an hour even when not needed. Put new filter, nozzle and flushed lines. Still does it, any ideas?

On 2015-11-27 by (mod) re: just hit reset one time

Try the reset button ONCE. that might get you heat whole you wait for a repair technician.

Check for clogged oil filter or nozzle.

On 2015-11-27 by Anonymous

burner wont start up was running before but is now not ignting . it was filled with 400g of fuel and we let it settle for four hours and was working

On 2015-11-23 by (mod) re: then check the oil burner aquastat settings


Good observation; now check the aquastat settings: on a typical aquastat multifunction control the LO must be 20 or more below the HI or it's locked out and will never run the boiler.

On 2015-11-23 by Anonymous

Thanks for your response. Yesterday I shut off all the thermostats when the boiler was hot and watched it throughout the day as the temperature dropped...right past the low limit set point, so my best guess at this point is a bad limit or other control part. Does that make sense?

On 2015-11-23 by (mod) re: possible chimney or draft problem fouls the oil burner

If the problem only occurs on windy days I suspect there may be a draft regulator order after adjustment problem or possibly something as simple as a missing chimney cap
Steve, the fact that your oil burner restarts when you push the reset button suggest to me that the problem is not a thermostat or sensor but more likely a problem with the oil burner itself or its fuel supply.

On 2015-11-22 by Steve

Any ideas? Boiler occasionally goes cold despite calls for heat. After reset it comes on and runs fine, for a while (last time for a week) before going cold again. It's like it does not recognize a call on temp drop. Could it somehow be flue related (maybe superstitious but it may happen on windy days). Any thoughts on what it could be are appreciated. Thanks!

On 2015-11-17 by (mod) re: do not keep pressing the oil burner safety control RESET button


Any of a number of problems can cause the burner to fail to ignite: out of fuel, clogged filter, dirty nozzle.


doing so risks a dangerous puffback explosion as you are leaving un-burned fuel in the combustion chamber. If the system finally ignites you could have a hell of a sooty boom.

It's time to leave the system shut off and call your heating service company.

Keep me posted


On 2015-11-17 by cameron

My oil burner turns on only when I hit the reset button the fan will turn on for 30 second but the burner will not ignite

On 2015-11-01 by Anonymous

My oil burner comes on for less than a second and goes off at odd times. Runs and heats great though.

On 2015-10-19 by Frank

My burner won't come on upstairs zone but it work in downstairs zone.I changed the zone valve, checked the thermostat. What else should I check?

On 2015-10-19 by Anonymous

I have a blinking green light?

On 2015-10-15 by Steve

Turn breaker on reset does nothing Stat all the way down motel or pump does nothing help

On 2015-09-30 16:24:08.595857 by rick

furnace hums but will not come on

On 2015-09-18 13:08:26.253843 by Brett

My boiler wont start by itself i have to keep hiting the reset button


Continue reading at OIL BURNER WONT RUN - home, or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.

Or see OIL BURNER WON'T RUN FAQs-2 - more-recent Q&A that help troubleshoot an oil burner that hums, buzzes, or just won't run



If the oil burner starts but does not run properly see these diagnostic articles

Or see OIL HEAT TEXTBOOK - an online PDF of a complete oil heat service text book (albeit an old one)

Suggested citation for this web page

OIL BURNER WON'T RUN FAQs at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


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