Oil furnace won't stay running...

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My oil heater starts but dont stay on & my green light keeps flashing. It's set to reach a certain temperature & once it below that temperature the heater is suppose to reach that set temperature but it starts up &goes out after a few seconds.
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snipped-for-privacy@gmail.com wrote in

Check to make sure the flue isn't blocked. This was the cause of my furnace shutting down a few years ago:
http://milmac.com/BlockedFlue.jpg
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On 12/23/2014 05:26 AM, snipped-for-privacy@gmail.com wrote:

First thing to do is replace the ceramic insulators, they can develop small cracks.
If that does not clear things up, your transformer is probably bad
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philo wrote:

I'd think if the transformer was bad it wouldn't light at all . Sounds more like a malf in the flame sensor circuitry to me .
--
Snag



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On 12/23/2014 09:36 AM, Terry Coombs wrote:

I'd say the more likely problem is the electrode insulators or possibly just a dirty flame sensor.
Yes. Not likely the transformer is bad but a small possibility of a broken/intermittent internal connection
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wrote:

I agree with this. The transformer should be fine since it does light. The flame sensor has an element which is a photo-cell. If it sees light (from the flame), it keeps burning. Those photo-cells can get filthy from soot and crud. They need to be cleaned. Or the photo-cell or another part of the flame sensor could be bad.
You could also be starving for fuel, if the inline oil filter is partly clogged. When was that last changed?
I had an oil furnace in the past, and was glad to get rid of it. They are always a struggle to keep working. If you're handy, pull the burner out of the furnace and clean the sensor. Otherwise you may need to call a professional. Oil furnaces are tough for the average home owner to repair.
The oil filter change should be done yearly, so I'd do that either way, if it has not been done in awhile.
One other thing, a pro will automatically change the nozzle. The spray pattern has a lot of effect on how it burns. So, if you pull the burner out, change the nozzle. You MUST use the correct one. They are rated by the amount of oil used. (My old furnace was .75), and they are also rated to the spray angle/pattern. Just match the numbers on the new one to the old one.
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On Tue, 23 Dec 2014 03:26:00 -0800 (PST), snipped-for-privacy@gmail.com wrote:

How many is a few? Time it, at least twice, and tell us how long it takes to go out each time.
By oil heater, dp you mean a full-size furnace, that heats the whole house or apartment?
There are a lot of things that can cause your problem.
When is the last time the furnace was serviced? The last time the nozzle was changed. They don't last more than 2 years and should be replaced every year. They are only 6 or 8 dollars on-line, inc. shipping, but make sure you buy the one speiified on the name plate inside your furnace. And be careful unscrewing that you don't hit and brake the insultators. A smallish wrench is needed for the inside hex, like a 6" crescent wrench.
Do you have a round door you can lift up? Get in the habit of using a long screwdriver, so you won't burn yourself when it's hot, and lift up the door before it starts. Do you see a flame or the light from a flame coming from where the flame would be? (not just a little light from a continous spark) Does the light last the same length of time as the furnace stays on before it goes out. Please get back to us with the answer to these questions, yes or no, and we'll give you more advice.
Do you hear the roar of the fire before it goes off?
Or just the small sound of a spark? Well, the spark you probably can't hear because the fan and oil pump make more noise that it does.
Does it just try again to start on its own or do you have to push the red button?
About how old is the furnace?
You can see several wires connected to the control board (in the box with the red button)? If your furnace is new enough to have a cadmium light sensor, and only the very old ones don't, you can test the sensor by disconnecting one of the wires to the control unit, Get back to me.
You can also test the ignition transformer before you buy a new one. Unscrew the bolt or whatever is holding it down on a side that does not have a hinge. Then press the red button to reset it, wait 30 or 50 more seconds until it tries to start up again, and whenever it tries to start up again, test the transformer by laying a long screwdriver witha well insultated handle (and you should touch only the handle--keep your hand at least 3/4" from the metal shaft) .... Lay the screwdriver on one of the big contacts that the transformer has and then get the end of the screwdriver very close to the other one. You should see a contnouse spark from the other one to the tip of the screwdriver. Pull t he screwdriver gradually away from the other one and the spark should get longer, at least a half inch. If it's 1/2 inch or even 1/4 the furnace should worlk, but the transformer is marginal. Let us know the r esults if you do the test.
The electrodes might not be adjusted correctly.
The insulators might be giving the spark an easier path than jumping the gap that ignites the oil but the service men have only replaced my insultators twice in 30 years, and that might been routine maintenance. They never came when the furnace was not working. All those times I fixed it myself.
If you have an oil filter, it might be clogged. It's the size of a car's oil filter, somewhere on the line between the tank and the furnace. I don't have one so there is no filter to clog, but aiui the filter element should be replaced every year, at least every two. If you replace the filter, you may have to bleed the oil line so many save the filter for last.
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On Tue, 23 Dec 2014 13:26:49 -0600, snipped-for-privacy@spamblocked.com wrote:

I don't think we know that it lights. It may just stay on until the usually 45 seccond start-up time expires. "On" meaning the motor runs and powers the fan and the pump, but we don't know there is a flame.

FTR, the burner is a lot bigger than that. Maybe you mean the nozzle assembly.

But if you're going to have one for 7 years or more it can be woth the effort to learn..

That should work, but one of the servicemen replaced a nozzle for me with a different one, hollow instead of solid. Maybe he had the idea hollow would be better, or maybe he didn't have a solid one in his toolbox. It did work for at least a year, but maybe not as well as the right one. It might be better to wipe the dirt off the metal plate with the model number, etc. That should include the nozzle spec.

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On Tue, 23 Dec 2014 03:26:00 -0800 (PST), snipped-for-privacy@gmail.com wrote:

The best page I've seen online to fix oil furnaces:
http://inspectapedia.com/heat/Oil_Burner_Wont_Run.htm
Very very very very thorough. No use of fancy tools required. Not a reference to them
If you ever want to do almost complete maintenance, however, you'll have to get a wet-dry vac that accepts soot filters. For Shop=Vac under its name or other names, that's everything but the tiny one and what used to be the smallest one.
For Ridgid, as of a few years ago, they didn't have soot filters by that name. They have fine dust filters or something like that, but the box and label made no reference to soot, which I think might be even finer than "fine".
If you don't use a fine enough filter, It will suck up the soot and blow it out the other end, all over the room.
But I think there's no chance that's your problem now. When I had too much soot in my flu, it made CO and set off the CO detector, but the furnace rand and it made heat. .
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wrote:

This is what he says about ignition transformers, a little different from what I said. Don't forget that this is in the context of having already deterimined that there is no ignition. Also scroll down to his list of sub-pages.
"Test the ignition transformer for spark (old timers know a screwdriver trick; if the flame is blue and reaches mostly across the gap of the transformer springs with the screwdriver an inch or so away, the transformer is probably ok.
Watch out: this is very high voltage: you could be shocked or killed - this old-timer's trick is not officially recommended and our service tech declined to be photographed performing this step. Other, recommended oil burner ignition transformer test procedures are provided by the manufacturer.
If the transformer is weak the spark will be dead, not bridge the gap to the screwdriver, or not extend to at least 3/4 the width between the contact springs, or will be orange not blue in color. If the transformer does not check out, replace it.*** If the transformer looks OK check closely the ignition leads including for cracked shorting ceramic insulators in the burner assembly or an improper or improper gap or damaged electrodes. You already looked to be sure the electrodes were not bridged with soot and crud, right?"
***Back to me. Still if there is a spark not quite this good, the spark might be good enough and another problem might be the main problem

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On Wednesday, December 24, 2014 12:10:23 AM UTC-5, micky wrote: Anyone notice that while you're all trying to fix the guy's furnace based on one basically nonsensical sentence, he's gone MIA? Maybe it's now too cold to type. More likely another troll.
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wrote:

There has to be some sort of "flame door". A little (usually round) door to open and see the flame. Open that door and watch what happens as it starts. Do you see a flame?
This is what you need to do first.
Basically you have two things happening in an oil furnace.
The oil comes from the tank, thru a filter, and to a pump in the furnace. Then it goes to the nozzle and sprays (like a nozzle on a garden hose) It should be a fine spray.
Next is ignition. The transformer creates the high voltage. The electrodes and insulators send a high voltage spark across the oil spray and ignites it.
That's pretty much how they work. If you ever held a cig lighter in the spray coming out of a can of spray paint, there will be a huge flame. (I'm not suggesting you do that). But that pretty much sums up how an oil furnace works.
There is one other system, and that is the circuit board and flame sensor, which allow it to burn if it sees a flame, or shuts it down if there is no flame after some seconds. If that was not used, the furnace would keep pumping unburned oil into the fire pot, and you'd soon have inches of oil in the fire pot which would eventually run out of the furnace and make a huge mess, if not cause a house fire.
Since you know th motor runs, you dont have a blown fuse and are you getting a spark? Is the oil spraying in the firepot? Is the flame sensor not allowing it to keep running (often due to a dirty sensor.
Again, check for clogged filter, change nozzle, and check for a spark.
So, 1. Check for spark 2. check to see if the oil is getting into the furnace and spraying. 3. Check for a flame sensor problem, which wont allow it to keep running
Just like working on a car. You need ignition and fuel.
Do you know, if you remove the whole burner assembly, short across the thermostat wires, connect to a fuel oil source, and connect it to an outlet, you can burn them ouside of the furnace?
DONT DO IT INDOORS. IN FACT, I DONT SUGGEST DOING IT AT ALL. (However I have done it outdoors, and know a guy who used to use one of them to heat metal for forging).
--
Maybe someone else can answer this. The oil furnaces I worked on were
in the 60's thru the 80's. Back then the circuitry was pretty simple.
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wrote:

You CAN remove the whole burner assembly. There should be 2 to 4 bolts around the round ring that holds it to the furnace. Remove them, remove the fuel line (and plug it), remove the AC wiring and the thermostat wires, The burner assy will pull right out. It's really not that hard to do.
Before you do all of this, make sure there is oil getting to the fuel pump. Just loosen the fuel line. Have a jar or can handy and see if oil flows out of the fuel line...... There should be a bleeder too. Kind of like the bleeders on car brakes. Use that to see if there is oil instead of loosening the line.
Of the oil tank was empty. You might just have an air locked line. My furnace used to do that regularly if i let the tank go empty. BLEED BLEED BLEED it.....
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On Wed, 24 Dec 2014 04:42:21 -0800 (PST), trader_4

His post was vague, but not nonsensical. Lots of people don't fully explain the situation when they first post.
As to MIA, it's only one day and 7 hours since his first post. Maybe he worked all day yesterday, shopped after work for hours, and had to go to work today. Lots of possible reasons why he hasn't posted back.
Or maybe he'll never get back to us because he's rude. Lots of posters don't bother to post back. Most are not trolls.

Trolls are those who try to rile up the readers. Nothing he said was like that.
Lots of people go without heat for a while, hoping to fix something themselves. They use lots of clothes, room heaters, boiling water, and electric blankets, and if they don't live in northern Minnesota they can go for a week or longer trying to fix their furnace on their own.
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On Wednesday, December 24, 2014 1:29:34 PM UTC-5, micky wrote:

I think it is nonsensical, when someone who obviously has no clue whatever, starts asking what to do about an oil furnace that keeps tripping the safety shutdown. If you don't even have a clue, can't begin to formulate a question, you should have sense enough to call for service.

Sure, so feel free to keep speculating without a clue. My car won't run. Please help me!

Most don't make ridiculous posts like that either.

It's certainly got folks here riled up, making wild guesses with nothing to go on. Real sound ones too:
"How many is a few? Time it, at least twice, and tell us how long it takes to go out each time. "
The guy appears clueless, do you really think it's a good idea to be telling him to keep pushing the reset button, trying to restart an oil burner, filling it with more oil? Or how to start testing it:
"Lay the screwdriver on one of the big contacts that the transformer has and then get the end of the screwdriver very close to the other one. You should see a contnouse spark from the other one to the tip of the screwdriver."
Come to think of it, maybe the reason he's not reporting back is you killed him.
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On Wed, 24 Dec 2014 06:31:50 -0600, snipped-for-privacy@spamblocked.com wrote:

I did this with an abandoned can of hair spray and a long kitchen match. once. But I was young and stupid then. I'm not suggesting anyone else do Iit.

The filters are not computerized, but you probably meant furnaces. ;-)
What many or all have that mine, from 1979, doesn't have is an oil pump solenoid valve, I think it's called. When the power to the burner turns off (but before the power to the air circulating fan cuts out) , the solenoid is also de-energized, the valve closes, and that prevents what must some kind of residual pressure from forcing or letting more oil into the firebox, oil that won't be ignited because the power to the burner is off and there is no spark**. I'm sure the absence of this valve is not a problem for most furnaces without it, but that the valve is a big help for some of them.
**My neighbor who has been asking my help, first with his bathtub faucet and now with his furnace, was surprised to hear that the spark ran all the time in an oil furnace. He had thought of it like a propane torch, a gas range, or iiuc a gas furnace, where the electric spark is just for starting the fire. . (Sometimes he really seems to need my help, but he's never accepted my offers to look at his furnace. I've seen his hall and his kitchen and they're both decorated and spotless. I wonder what he's ashamed of in the furnace room.)
The new control boxes have the same connection screws as the old ones, but one or both of the mechanical parts of the control panel may have been replaced by semiconductors. Also they have an LED that goes on (or maybe off) when the control panel is in lockout.
And the new ignition transformers aren't even called transformers anymore, aiui, because either they have parts in addition to the transformer or they use some other, semiconductor method to up the voltage. Look at the profile of the one that Home Depot sells online. It's lower, and might show some lights too, iirc.
Maybe adding remote control via the internet to furnaces has only affected the thermostat, but maybe it's brought extra parts to the furnace control box too. I don't know. But if you get one without remote features, I think it's not that different from the ones you worked on.
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On Tue, 23 Dec 2014 03:26:00 -0800 (PST), snipped-for-privacy@gmail.com wrote:

Thanks for sharing.
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On 12/24/2014 2:15 PM, Oren wrote:

- . Christopher A. Young Learn about Jesus www.lds.org .
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Oren posted for all of us...

Really, I think this topic has been posted at least three times lately.
--
Tekkie *Please post a follow-up*

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On Thu, 25 Dec 2014 03:51:06 -0800 (PST), trader_4

That attitude is what I think is nonsensical. Lots of people don't know what they're doing until they start doing it.

He gave a lot more details than that.

That's not what I meant by riled up. Did you really think it was?

If part of my answer was bad, that does't make the OP a troll. When you post something silly does that make the OP in that thread a troll?

You're a trip.

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