Oil burner lockout

JeffD

Hmmm, are you sure your not sucking in air through a bad flare fitting? Do a vacuum test on your fuel line and see if it holds, that will tell you if you are sucking in air. Check pump screen while you are at it. Does this burner utilize an oil delay solenoid, could the solenoid be weak or sticking? Just some thoughts. Excellent thought about combustion testing Alan, and checking the Z dimension.

Bill Price H.W. price and Sons, Inc. Heating/Air C

Oil burner lockout

Customer has a Beckett AFG burner with a .65 nozzle, and static plate is installed.
Says he has to reset burner once a day, usually at night, and burner fires immediately.
We installed new nozzle and oil filter,plus checked electrodes,t-former, and cad cell. primary relay works.
Is it possible we have an airlock in pump, blocked pump screen, or other blockage in fuel delivery? we are pulling our hair out over this one.
Any feedback would be appreciated.

Alan R. Mercurio_3

Bill, has any of the following been done yet? Combustion results taken Co2, O2, CO Smk Draft o/f a/b how about pump pressure and vacuum? Z – dimension? Some of this information will not only help you locate the trouble but also help us help you a little more

Your friend in the industry,
Alan R. Mercurio

www.oiltechtalk.com

Firedragon_4

First thing

to do is replace all of the wire nuts, especially the neutrals. Most troublesome area is at the back of the burner in the bulkhead passageway and then the j-box. Most of my nightmares on burners have been electrical FACT!

Don't forget if the wires do pass through the bulkhead to check them by running them through your fingers. They get pinched as the ignitor/transformer is closed. Tape everything down with a piece of duct tape.

jrc2905

have you taken cad cell readings? If so what kind of motor is on unit?

Guy_6

electrodes

Are the electrodes a slick, polished finish, or dull and chalky? I have had the dull ones give troublesome "has to reset" issues.
If a gravity fed flare nut was failing, I would expect an oil leak.

Are there any other oil fired appliances drawing from the same tank? If so, one may be starving the other.

pitman9

I agree with Alan plus

if the numbers are all good (particularly over fire draft) you may want to take a closer look at the primary control. An even rarer occurance is a motor with a sticky centrifugal switch, but it does happen.

Al Gregory

Could be a bad pump coupling or a dead spot in the motor but with the AFG and a small nozzle like that it is probably not firing. Just out of curiosity what is the small air band set at and is the large band closed all the way? What kind of boiler or furnace is it in?

Alan_11

lock out

Lanthiers rules Fuel ONews Time for On Watch ? Every year we all have a few of these calls.They work fine until your out the door and then decide to act up. Oil valve , motor , electrodes, primary. transformer. Last winter took 5 callbacks to find primary I replaced on 1st call was N.F.G. Get OnWatch and take the guess work out of the equation.

Tundra

Primary

Every once in awhile I run across a primary that has an intermitent problem. It always works when I am there but as soon as I leave it starts laughing and locks out again.

tommyoil_2

Basics

First off, a .65 is a pretty small nozzle. If you change the nozzle and filter and NOT the pump strainer you are doing a disservice so start there. After that, I would put a hand pump on the fuel line to get any excess sludge/dirt out of the fuel delivery system. If the fuel tank/lines have been in service for awhile there is a pretty good chance that the bottom of the tank and the lines are gunked up. That and the fact you are running with a .65 you stand virtually ZERO chance of continual operation without a breakdown. Make sure you re change the nozzle(and use the spec nozzle for the unit) filter and strainer after you clear out the oil lines. THEN I would get out the pressure and vacuum gauges to see whats what. Pressure and vacuum readings will tell ALOT.Make sure your readings are within operational range. After that I would go down the line (transformer test, primary relay check, ohm reading on the cad cell, electrode check for cracks/breaks,loose wiring). If all seems "normal" get out your combustion analysis equipment and put it to work. My initial thought on this post was small nozzle combined with dirt. Get the oil lines cleaned out!! When you say static plate do you really mean low fire baffle?? Also what type of system? Furnace?? Steam?? Hot water??

jrc2905

If it is the older start switch oil burner motor, and not the new PSC motor then change the motor. I hate being a parts changer but sometimes you cannot find the problem with a meter. The switch gets stuck, burner tries to fire goes out on safety, cools down and resets and then starts when the primary is reset system starts. Every year I get a couple of these sometimes it is the motor, sometimes the primary, makes me feel like an idiot

Alan R. Mercurio_3

Jrc, I'm just wondering have you ever tried the following test? I have this as a tech tip along wiht a few others on the Oil Tech Talk Pocket Pal and that's free! all you need to do is send a self addressed stamped envelope and I'll send you one.

CHECKING THE START SWITCH: 1/7 H.P. MOTOR

We will check for a faulty start switch by using our volt/ohm meter set to measure resistance (OHMS). In review, the motor start windings have a much lower resistance than the run windings do. This difference is what we will use to determine if the start switch is defective.
Using your meter set to measure resistance or ohms, set the scale on the meter to measure the lowest resistance available on your meter.

Turn off power and remove the motor from the burner housing. Place motor in a shaft up position. Disconnect the black and white motor input leads. Connect your meter between the black and white motor input leads. If the start switch is functioning properly, the resistance should be approximately 2-4 ohms.

If this resistance is much higher (in the range of 7-10 ohms), then most probably the start switch is bad or your meter is not adjusted properly.

To double check if the start switch is bad, pull up on the motor shaft and note if the resistance drops and your meter reads the proper 2-4 ohms. If this happens, the start switch is most definitely bad and motor should be replaced.

The most important function of this test is to make sure that the resistance across the motor leads does not change when the motor shaft is pushed down or is rotated 360°. When rotating the motor shaft, let the meter settle down before noting the resistance.

In conclusion, if the measured resistance was approx. 2-4 ohms and did not change when you pulled up on the motor shaft and did not change when motor shaft was rotated, then the motor most likely is not at fault. If the motor continues to exhibit starting problems in operation, then it should be replaced. I learned this from John Gates May God Rest his soul.


Your friend in the industry,
Alan R. Mercurio

www.oiltechtalk.com

jrc2905

I have read and tried this test to no avail. It may work if the start switch is stuck in the open position. I believe the start switch just gets stuck and then closes, I have thought of using electric motor cleaning spray, but this is a rare but frustrating problem.
I have had people tell me the problem is a dead spot in the motor, but wouldn't that prevent the motor from starting when the primary is reset?