Old Burnham Boiler Shuts Off


Hi All,
I am writing because I am pretty much out of ideas. I am hoping that someone on this group will have more expertise than I have.
Anyway here is the situation (all that I know). I have a 20 year old Burnham Oil Boiler. It provides hot water for heating and a tankless hot water system for the house. It was serviced in the fall by the oil company.
The heating in the house is in 2 zones, one zone is programmed to change temps during the day to save on heating, and the other is maintained at a temp of 62F.
The furnace seems to shut down erratically. Sometimes at night, sometimes during the day. There does not seem to be any pattern to when the furnace shuts down. Once the boiler shuts down I have to press the reset button to get it re-started, and when I do that it fires up first time with no problem, no loud noise and no puff of smoke.
I called the service people out, and they have so far replaced, filter, electrodes, nozzle, cad cell relay, pretty much everything. The service man also said there is a good amount of current, a good stream of oil and good oil pressure. None of this seems to have made a real difference.
The boiler still shuts down every couple of days in the New England winter, and much less frequently in the summer.
I thought that short cycling was to blame, and therefore changed the Cycles per Hour on the thermostats. This also did not make any difference.
If anyone has any ideas on what to check or try I would really appreciate it, as I am pretty much out. Other than a new boiler :)
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snipped-for-privacy@gmail.com wrote:

Suppose it has nothing to do with the "boiler"? What I mean is, you can't make assumptions when investigating a mystery.
How about something like a very small air leak in the oil suction line? The pump gets air bound and it takes a short time to work the air out. (Just as one example.)
Is it a one-pipe supply from the tank? They are more prone to problems. Buried tank? Also problems.
Still on that tack, my approach would be to install a pressure gauge on the pump. Watch it every chance you get to see how fast the pressure builds on cold start-up. The needle should just go "BANG" right up to 100psi even before the motor reaches full speed.
Or...could there be contamination in the oil? Water deposits?
In really desperate situations, it may warrant running a temporary copper line dropped into the tank opening or even into a 55 gallon drum of oil to prove/disprove oil delivery problems.
Jim
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I am prepared to think it is anything in the entire system, hence the adjustments of the cycles per hour :)
As for the oil supply line, yes it is one line. The tank is indoors (basement).
With regards to the pressure, when the service guy tested the pressure he mentioned that it was 100psi. Can the oil delivery pressure be affected by the temperature?
marc
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snipped-for-privacy@gmail.com wrote:

No, the pressure is tightly controlled by the internal regulator in the pump. The critical point isn't the exact value of the pressure, but rather how promptly the pump builds pressure precisely at start-up. If the thing sputters for a few seconds once every 20 starts, that's when you will have a shutdown. Very elusive.
Jim
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ok so say i was going to install a pressure gauge. Where would I install it? Can i simply disconnect the oil feed line and put a pressure gauge "inline"?
Also if there is an air leak in the line, would it stand to reason that I would see evidence of it every time it fired up, or is it something I would only see when it faltered and failed to fire?
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snipped-for-privacy@gmail.com wrote:

There is a port on the pump (has a plug in it) where a gauge gets screwed in.
Might not see evidence of a leak every time.
Maybe stop by the library and see if they have a book on domestic oil burners.
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I will look for the make of the pump, and see if I can find the port. thanks for the ideas Jim
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Just a thought . Have you purged the line to see what comes out ? Put Air pressure to the tank and fill a quart jar to check for blocked line? Piece of plastic floating in tank or something of that nature? Years ago I had a sliver of .005 fiberglass in a water softer drive me nuts It would float around and every so often block a injector port but 99% of the time it worked just fine. I would also check all wire connections closely

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Did your Service man check the high voltage transformer? That and checking the gaps of the electrodes..The transformer may still be arcing, but it might have lost its true fire! I had a similiar trouble..put the xformer on the bench, and take a insulated screwdriver, starting from one electrode, and moving to the other. You should draw an arc at 3/4 inches.
My old one would arc but I almost had to touch the other electrode, before an arc would start! Don't forget ,you also have a draft fan blowing at that arc! The gap between the electrodes should be aroud 1/8 inch.
My 2 cents worth! >
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Instead of hitting the reset button, next time it does it 'gently' rap the motor with something like a small rubber mallet or screwdriver handle to see if the furnace fires. It could very well be the motor is failing (sticking like a car starter) as well.
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