Oil fired forced air heater not working

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  #1  
Old 01-02-03, 06:58 PM
twkern
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Question Oil fired forced air heater not working

I have an oil fired forced air heater in my garage. It was not running properly so I changed the filter, cleaned the unit and all contacts. It runs intermittantly. I get it going and it works for a day or so and then I have to hit the reset button. I get a puff each time so its getting fuel and I can hear the ignition working. I opened everything up again and it was soaked with fuel. I pulled the nozzle and the filter on the inside of the line was clean. What would cause this? Do I need to replace the nozzle each year and what is the proper spacing between the two electrodes? Any help or tips would be appreciated.

Thanks
 
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Old 01-02-03, 09:45 PM
H
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are you kidding??

a high pressure burner isn't something to hit or miss with, Don't burn down the house to save a few bucks. The nozzle is replaced every year along with the fuel filter. The air filter is replaced whenever it becomes lightly soiled (for furnaces). Electrode settings are critical, along with air gate settings, and barametric damper settings, Z distance, end cone distance, and many other things but extremely dangerous if your not a skilled tech. Be afraid....Be very afraid....
The oil saturation indicated in the combustion chamber, needs to be removed first, depending on how much is in there. I'm curious what would posses you to try this?
 
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Old 01-02-03, 09:49 PM
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It could be many things but I'll run down a few and you can try them. I have no idea what make and model burner you have on you furnace so I can only genralize. Unless you have a pre 1970 burner the electrodes should be about 1/16" forward of the nozzle face and about 3/8" above the centerline of the nozzle and about 3/32" apart. If you flip the transformer back and run the burner for a few seconds, you can with an INSULATED screwdriver, draw an arc from one spring terminal to the other on the transformer. Keep one hand in your pocket as you do it. Your heart will thank you for it someday. You should get a nice BLUE spark that will not break until you get over 3/4 inch gap. Start with the screwdriver shorting the two terminals and draw it away from one while keeping it against the other. If you get a yellow spark that hardly makes any noise and doesn't reach 3/8" you need a new transformer.

You could also have the wrong nozzle or the retention setting on the nozzle tube could be out of whack. I would need more burner info. to help you there.
 
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Old 01-02-03, 10:05 PM
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Oh please. I see gas questions answered here all day long, the odds of there being enough fuel to cause even smoke in the garage is pretty small. If he said he comes in and it's running but no fire and fuel is seeping out of the furnace, we have a problem. But an intermittent lockout isn't exactly a big deal. A nozzle is rated for 100,000 gallons. Hago and Delavan both say that. So if you keep the dirt out, you should be able to squeeze a second year out of one.

I never saw an air filter or barometric damper be the cause of intermittent lockout.

I thought he was looking for a lead and I gave him one or two.

I did forget to tell him roughly how to set up the fire though. It should not be tight like a jet engine. It should have some wispy tips to the flame but not smoky. Wait until it has been running for 5 minutes or so to set up the flame. That way draft is stabilized and the combustion chamner is fully heated and all unburned fuel from the last cycle is gone.

I was told once not to take the back off of my TV because there is High Voltage in there. I did anyway and found a small fuse was blown. I replaced it and the set has been going for many years. I wish someone would have at least said "give it a try". As it stands now there isn't much I won't try and maybe I'll die trying. But thats how I would prefer to go.
 
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Old 01-02-03, 10:17 PM
twkern
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Re: are you kidding??

Originally posted by hvac01453@juno.
a high pressure burner isn't something to hit or miss with, Don't burn down the house to save a few bucks. The nozzle is replaced every year along with the fuel filter. The air filter is replaced whenever it becomes lightly soiled (for furnaces). Electrode settings are critical, along with air gate settings, and barametric damper settings, Z distance, end cone distance, and many other things but extremely dangerous if your not a skilled tech. Be afraid....Be very afraid....
The oil saturation indicated in the combustion chamber, needs to be removed first, depending on how much is in there. I'm curious what would posses you to try this?
RELAX DUDE! Cleaning the unit and replacing filters does not take the talents of a brain surgeon. There was no oil saturation, just oil on the nozzle when I removed it. The first time I took it out to clean it everything was dry. Once I found that this did not solve my problems I reached out for some professional knowledge. As for the skilled tech, the last owner had one and that is why I have a unit that runs the way it does and was in such poor shape. Just because someone gets paid does not mean they are a professional. This is not an emergency job and I have the time to do it right, in addition to "saving a few bucks". I have a career in fire and safety and over 20 years of putting out burner fires in the fire service. I don't take short cuts and I don't take chances when it comes to this stuff. But I do appreciate your concern.
 
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Old 01-02-03, 10:40 PM
twkern
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Thanks KFIELD! I have to agree with you, I am the same way. I have the information on the unit. Its hard to say how old it is but my guess would be that it goes back to the mid to late 80s. The unit is a Lenox Model 012Q3-105, Input 105,000BTU/hr and a max firing rate of 0.75gph (which matches the nozzle that I have).
The compressor is a Sundstrand Model B2VA-8216, 3 GPM at 100PSI. The Motor is a Marathon Electric 3450RPM and .14HP and the Ignition Transformer is a Webster Type 313-24AB82.

Thanks for your help.
 
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Old 01-02-03, 11:35 PM
H
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just a thought

you mentioned the TV set...My uncles house had a fire and I was going to fix the TV set to work again (back in the days of radio tubes, I left it unplugged for 7 to 8 months to discharge all lingering power, While pulling the first tube I got a wallop that knocked me back to the wall.
I didnt know one should short the chassis first.
As to the oil....you said it was soaked . Any service tech will tell you, all customers swear they hit the button once ,so as not to look foolish. Then you look in the combustion chamber and find a puddle of oil, good thing you didn't hit the reset, your luck it lights that time, with a nice puff back, blows the stack to pieces and soot is everywhere....someone I knew that almost always checked but once...
Sounds like ignition is the problem, reset the electrodes, spring for the $5.00 nozzle. If you changed any of the settings, all bets are off. I don't think you have a smoke tester, do you? If so ,
open the air gate to get a smoke of trace to 1, get the CO2 to about 12. The pressure over the breach to -.02. If you have a .75 GPH furnace , go down to a .65GPH and increase the fuel pump pressure to 135PSI, this will increase the efficiency of the burner unit, using a .75 on a .75 furnace indicates the pump pressure is most likely at 100PSI, the higher pressure atomises the fuel better, the good techs know this, the marginal ones change filters and nozzels for a living (don't have the Bachrach efficiency test kit, much less know how to use one).
 
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Old 01-03-03, 10:20 AM
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I agree with hvac this time. The difference is that good techs. customers don't think twice about calling for service. But the incompetent unprofessional techs make everybody with a tool kit think they could do just as well.

I would change the strainer in the fuel pump, change the oil filter at the tank or burner or both, replace the nozzle (the higher pump pressure is a good idea also but you must mark the burner so nobody ever goes bact to the max nozzle size without reducing the pressure), check and adjust retention setting, check the ignition transformer, check the pump pressure and cutoff, fire it up and check the safety timing then adjust draft, check smoke, set the CO2 to around 11 (to leave a slight margin for cleanliness so it is still burning clean next year), lube the burner motor and blower motor, and check the thermostat.

Occasionally, one of those things opens another area that needs attention but thats why preventive maintenance is worth doing. A full fledged cleaning takes more time but if the unit was running efficiently, there is not much else to it.
 
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Old 01-03-03, 03:13 PM
H
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OIL

I agree with KFIELD, I just assumed that when you said you changed the filter, you meant the fuel at the fuel tank, there are 2 more fuel filters in the line. Proper procedure is to change the tank filter and bleed fuel through the pump till you get about a half gallon, pour that back in the main fuel tank, thenreplace the basket as Kfield said or if your a penny pincher Clean the basket(this should be done every 3 years), drain a little more fuel thru the jetline, THEN.......replace the nozzle, because anytime you disturb the line small amounts of dirt will dislodge and the the filter get dirty faster. Stringy flame, none, flame to one side, acrid odor , after burn are all common nozzle problems. The reason we replace them is because they are cheap. If it was $30.00 it might be a different case. A new fuel filter,Nozzle, basket, gasket, boiler brush, surgical gloves, speedy dry, air filter (for furnaces)and vacuum cleaner bag is under $30.00, now your labor ....???
 
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