Gas and Oil Home Heating Furnaces - oil furnace shutting off

2-3 times a month my oil fired furnace just shuts off for no apparent reason.
I press the restart button and it comes back on and runs till the next time.
I had it serviced at the beginning of the heating season(oct) and it ran fine till about a month ago. I am going to have a heating tech. look at it,but i want to know what questions to ask,what should be checked,what was the problem?
Any suggestions what might be wrong?
Thanks

2-3 times a month my oil fired furnace just shuts off for no apparent reason.
Getting air in oil line, clogged or frozen oil filter, dirty flame sensor, intermittent loss of spark.

Do you have a nice fire when it is working? Or is it burning rough?

Furnace seems to run fine other than shutoffs.

If when you hit the reset button the heater starts with no rumble or smoke, I suspect the start switch on the burner motor is going bad. It is easy to check if the tech knows how.

On manual restart,it briefly rumbles for a second and sounds normal from that point on. After start up there is a smell of oil fumes for awhile but no smoke and the smell goes away.

OK, That tells me the burner is trying to start & rules out the motor. The problem could be in the fuel system or the ignition system. On the fuel side it could be dirty. On the igniton system, the transformer could be weak, the electrodes worn or misadjusted or rarely a buss bar could be cracked. Electrode porcelains crack sometimes but resetting will usually not get you running. Let me know what the tech finds.

Thanks bolide and grady,

I will post back with the results when its fixed.

I'll put my money on weak ignition or poor electrode setting.

Ken

Great help and advice.

Update as promised:

The problem was a couple of things. (?) The electrodes were not gapped right,
trace of oil on the insulator,and wrong jet nozzel.

Will have to wait and see if this corrects the issue.

Thanks again to all who replied.
daswede