Infrequent, delayed ignition

[webster72n]

With my conventional, american standard oil burner for a hot water furnace I am experiencing infrequent, delayed ignition. At times it ignites properly and most of the time the ignition is more or less delayed by 3 - 5 or even more seconds, resulting in fueloil fumes residue. All settings for the electrode are proper. The nozzle is new and was installed without bare-hand touching. Could the deminished quality of the oil have anything to do with it, or is the cause to be found somewhere else? A positive answer will be very much appreciated. Thank you.

[Grunff]

I'm afraid it's unlikely anyone here will be familiar with that particular burner, so you may not get a specific answer.

However, in general, if you're experiencing delayed/unreliable ignition it will be due to (surprise!) poor ignition system. What do the electrodes look like? Are they in good condition? Corroded? Is the gap ok? How about the ignition module? how old is that? Insulation in the transformer can degrade with age, so it may need replacing. What about the HV cable from the ignition module to the electrode? Is the insulation on that intact?

[webster72n]

ignition

[John]

From your use of the term hot water furnace you sound as though you are at the other side of the pond. I do not know what you mean by an american standard type oil burner but on the off-chance it might be a simple? pressure jet burner you could check that the positional settings of the electrodes in relation to the burner nozzle and the blast tube/swirl plate are correct. Also the high tension connections and the ignition transformer. Some newer burners use an electronic ignition generator (Danfoss EB1 or equivalent) which can and does give intermittent problems when warm. Also the sequence control unit and the solenoid valve/coil connections. Have you checked the mechanical coupling between the motor and oil pump and any filters or valves between the oil tank and the pump? You may be better off asking the burner manufacturers for advice

[Grunff]

I'm afraid I really have no idea where the ignition module might be located. The transfromer is the main component inside the ignition module. Follow the high voltage wire from the electrode - it will take you to the ignition module.

Good plan - at that age, it may well be very degraded.

Good luck!

[webster72n]

american

transformer.

thoroughly.

incorporated by

[webster72n]

It's in the relay, Grunff, I am sure, because that's were the wires lead to. What puzzles me is the fact that it shuts off perfectly,only the ignition shows problems. To be sure, I am going to replace the two electrodes. The quality of the fuel oil then doesn't have anything to do with my problem? I certainly can use some luck, Grunff. Thank you.

webster72n

[Grunff]

Right, so the 'relay' is more than just a relay; it's an ignition module.

No, that would be typical of a failing ignition system.

Really need to check the coltage output of the ignition module - but without specs, this is not easy.

Oil is a very crude fuel anyway - it has to get pretty bad before you start experiencing ignition problems. What makes you think you have a quality issue?

[John]

Well we are in the UK since you have asked your question in the UK d-i-y newsgroup

I wonder if your oil pump is starting to wear and not giving constant pressure allways. Try fitting a pressure gauge to the test point and observing the pressure over a longish running period. What sort of diminished oil quality were you referring to?

[Owain]

"webster72n" wrote | > From your use of the term hot water furnace you sound as | > though you are at the other side of the pond. | Thank you for your input, John. Which side of the pond do you mean? | I am right here in the good old USA, Pennsylvania, to be specific.

We're right here in the even older Yoonited Kingdome. There's a subtle hint in the newsgroup name. Feel free to ask about any problems you have with electrics, blocked toilets, or deep frying turkeys :-)

Owain

[webster72n]

Now there's a thought, John, I'll try that pressure test, yet the oil is being fed, but not ignited properly at all times. To tell you the truth, I've been giving all these possibilities consideration, only to keep coming back to the ignition factor itself. and that could be influenced by the quality of the fuel oil in my opinion. You see, John, over here they sell you the oil "from the bottom of the barrel" so to speak, which contains water. It is not supposed to happen, but it does. Also for quite some time the oil contained cleaning agents to make it burn more cleanly. That has been omitted, even though they assure me , it not to be so. Where location is concerned, I figured yours correctly and exactly for the reasons you mentioned. What amazes me is, my search for answers "on the other side of the pond" led me to your NG. None to be found in the whole US of A. Nevertheless I will keep digging 'til I find my answer and once I do, I shall let you, Grunff and Owain know about it. Thanks to all three of you.

Cheers,

webster72n.

[webster72n]

Hello Grunff:

If the ignition system were failing, shouldn't the symptoms be constant instead of the unpredictable infrequency it shows? In any event, I will check the voltage output of the ignition module. No problem - I think. For the rest of the story, please have a look at my last reply to John. Thanks for your readyness to help beyond expectations. Cheers to you too, Grunff.

webster72n.

[Grunff]

Not at all - ignition problems can be very intermittent. Various environmental factors (temperature, humidity etc) can affect the developed voltage, and the ability to generate a sufficient spark.

I wouldn't rule out oil quality at this stage, but I'd want to be sure the ignition was working 100% before digging deeper.

You're welcome.

[webster72n]

Hello Grunff, John and Owain:

As promised, here is the solution to my problem, as simple as it may sound: According to recommendations, the ignitor tip is supposed to be 5/8" above the nozzle center (American Standard) and 1/2" (Internet). The gap between the two tip ends is 1/8". Those dimensions are critical, as my manual states. When I called the serviceman today, he went right to the ignitor and bent the tips down to within 3/8" above the center of the nozzle. That's all there was to it. Can you imagine my reaction? Those recommendations in all probability are tailored for clean fuel oil. After going through countless trials and tribulations, one tiny action restored normalty, even without the need of any new parts. But, I look at the bright side, it gave me a much better insight into the workings of my furnace and will enable me to service it more efficiently. Thank you again for your assistance and may you have the best of holidays and a healthy and prosperous New Year.

webster72n.