72chevy4x4

I've been chasing down a firing problem w/ 'my' furnace for years. each year, having a tech come out and service it, but the next year the furnace stops firing in the middle of a night. typically starting after hitting the reset button.

today, I pulled out the burner to inspect the unit. Initial inspection showed the electrodes were nowhere near factory specs-spaced 1/2" from the nozzle and 3/4" apart. I put it back to factory specs, cleaned up the burner assembly and closed it up. Had to reset the burner control a few hours later-turned out the burner assembly turned slightly and I 'think' the electrode wasn't making contact with the ignitor. Any ideas what to look out for if it keeps going offline?

The last service tech installed a nozzle different than that which is designated on the oil burner/casing. A 80 degree B 1.10 is called for but a 1.00 is installed. What ramifications does this have? Should I check the Z dimension to ensure burner efficiency? Do you guys do this when servicing a burner?

72chevy4x4

more troubleshooting...I pulled out the ignitor and observed the spark during startup (no fuel). Strong initial spark, then it dwindles quickly. Can the transformer for the ignitor circuit be going bad-giving a strong initial spark then weakening? Does a cold transformer sometimes perform more poorly?

painterman

I have had similar problem with my Beckett burner. Would have to reset it in the middle of the night. Run fine for about 6-8 hrs then have to reset. Replaced the burner motor and all was well. The tech figured that there must have been a dead spot on the armature. Hope this helps.

mdshunk

There's lots of things to potentially go wrong on an oil burner, but they're pretty easy to work on. Beckett's are the best and the easiest to service. You need three things to support combustion. Fuel, spark, and air. All three are measurable and observable in your unit. The test for the secondary of the transformer is to flip it open, draw a spark across the terminals with a screwdriver, and see if you can lift it at least 3/4" for a period of time. There are testers for this, but the screwdriver test works fine. From what you report you have observed, I'd recommend you do this test. If that test goes well, check the porcelain insulators for the electrodes. Clean them up well and inspect for cracks that might be "leaking" spark and not making the electrode tips spark hard and nice.

Leo G

I had this same intermittent failure to fire on my furnace. Had been working fine for 17 years and then one year started this random shut down.

Replace the ignition coil. I got mine from HD for $32. You can get it from a reputable dealer for about $60 or have your tech install one for about $120. Simple to do, should take about 15 minutes start to finish. Good luck. Being cold sucks.

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Measure Twice Cut Once -- It's a lot easier to cut more off then it is to cut MORON. http://lrgwood.com

72chevy4x4

I tried the screwdriver test for the ignition coil-got about 5/8" of a spark for 8-10 seconds (timed out).

also used a file to file down contact points for spring and end of electrodes. we'll see if it gets cold in the middle of the night!

Leo G

My coil consistantly checked out good. I just ran out of options. I asked around and a few guys said the coils can get hot and get a weak spark. Usually it will fail on start up. Once it is lit it will usually keep going.

__________________
Measure Twice Cut Once -- It's a lot easier to cut more off then it is to cut MORON. http://lrgwood.com

72chevy4x4

well...since taking the electrodes out and filing down the ends and contact point where the transformer's springs make contact, I've had no problems. Maybe bad contact between the springs/electrode?

flashheatingand

Good Job, Good for you