Posted on 02/26/2016 4:36:04 PM PST by Ghost of SVR4
G'evening folks...Just a bit of HOWTO this evening if anyone is inclined.. My furnace started acting up on me two days ago. It would run for about 90 seconds then cut out; blower still ran, then rinse and repeat. I did quite a bit of the googles and came to find it was either a thermostat (main) or a limit switch. Welp, replaced the thermostat (I'll post later in this thread about those interesting findings) and same results. Had to order the L150-40F limit switch because no store around me would sell to the "general public" and the home stores did not carry them. Soooo..Had one flown in from another state. Part? 9 bucks. Shipping? 30. (rolls eyes). Okay, so, new part in. Still the same results.. UGH...its cold here and I have to get this pup fixed.
Turns out, my filtrete filter had bad markings on it. The "airflow" arrow (which I have followed for 15+ years) I believe was marked wrong. I pulled the filter and my furnace came alive and went back to doing its job. I replaced the filter (which was only 4 months old) and checked my input airways the best I could.
So, the furnace is humming along, but when she shuts off, after about 45 seconds it emits white smoke. Not enough to kill ya or set off a fire alarm (I have one in that room as I type). I pulled the the electrodes and nozzle assembly and I admit, a bit gunky so I replaced the nozzle and cleaned things up a bit (note, I did not have to re-gap the electrodes). Got everything back together and still some white smoke comes out after the burner is off (around 45 seconds) and the blower is still operating. It lasts for a bout 45 seconds while the blower is still doing its thing and once that is done. POOF, it all stops.
I'm wondering if there is some residue oil just cooking off after a couple days of cycling so much, or? Any ideas?
I do not believe my home is going to burn down. Yes, yes, I know, call a professional and I probably will since I want to sell the place in six months and want everything tip top for the next owner.
This is just eating at me because I cannot figure it out and these furnaces are not extremely complicated.
Beckett Oil pump AFG, 70/70-A nozzle (replaced) calibrated, Generic burner.. Type II fuel oil.
Anyone seen this before??
LOL!!!
and I was trying to think of a joke using “Tinder”....
Can’t top that one though...
The pipe...
Where else would it come out of?? /s
The entire unit is only 650.00 installed around here; fuel/oil burners are cheap (and very well engineered; kudo's to those folks).
Switch. I watched through the access point.
I think the last nozzle was drizzling some oil through lots of cycling and the blower cutting out because of the bad filter..
I think you hit on the problem.
I say the fuel isn’t shutting off cleanly, the solenoid isn’t closing properly and so a little continues to dribble out.
With the igniter off the fuel just smokes instead of burns.
I say a solenoid replacement.
Unless the furnace has a mechanical valve that opens when the pressure of the oil pump forces it open, and closes when the pump turns off. I say it’s not closing. Then I would look at that.
Habamus Papa!
Exactly!
Too bad you feel this way, FR's post's are cached on google searches in almost real time; "other's" out there may be experiencing the same issues and at least can figure out their problem and not get fleeced by a shady contractor (you're not a contractor are you?) over a weekend (emergency fee). But, my post brought you to posting, so, thanks (I think) as when I sell the place in six months it will come with a 1 yr warranty for the next buyer as I am not a douchebag; just a guy that enjoy's fixing problems. Sorry you are not?
Not where I live. I have “property” and the water well is 750 ft’ deep. Nice try with the doom and gloom though; might be better served over at ZeroHedge.
Or was that sarc?
Exactly! I can attest! About three weeks ago tonight.
Nope, it runs just fine. No button needed (and yes, I’ve used “that” button before when it caught me off guard and I needed a top off).
one of the things he looks for is smoke coming out of the exhaust pipe.
He said:
If it's white smoke I won't buy it because that means a blown head gasket (water in the exhaust).
If it's blue smoke I won't buy it because that means the motor is burning up inside.
If it's black smoke I WILL buy it because that means it just needs a tune up so I'll give it to my mechanics to fix up.
A dirty bomb left behind by prior jihadi owner
Nah, my “output” stack is underneath a VERY LARGE oak tree; I’m just feeding her, nightly (well was every 10-15 minutes). That Oak is thanking me right now...
Did you check this site that I linked to earlier:
“I have a fuel-oil furnace that white smoke appears through the burner after the burner shuts off and the blower is still running, after about 45 seconds...white smoke starts to come out of these small holes on the burner and fill the basement with white smoke and smells like fuel.
I changed the air-filter about a month ago and the oil-filter, too. I had to install a new blower motor like 2 months ago because the bearings went up...and just recently I decided to open the inspection cover and look into the furnace as it was running and I could not stand the heat. It blew out and if I was within 4 feet of directly in front of that inspection door the heat was unbearable and so I tried to look in from an angle and noticed that the flame inside was about a cubic foot in size and was bright yellow. I don’t know if it supposed to be blue or if that is only on natural gas furnaces or not.
I looked up the chimney with a flashlight and mirror from a cutout in the bottom where it seems years ago there might have been a coal burning stove and I could see a square sunlight at the top, so I figured the chimney is fine.
The swinging small door, I think is a damper swings fine but seems a little weak. I really don’t see any smoke in the flue.
The furnace works fine... I am just concerned about the white smoke that appears coming out from small holes in the burner assembly itself. I did just 2 weeks ago vacuum out a lot of rusty scale buildup inside the furnace and in that inspection door I used my hand to sweep out a lot of rusty scale buildup, too and it seems it fell into and all around the burner assembly since it is positioned directly underneath where I was trying to clean, but I used compressed air after I seen smoke and blew out as much dirt and rusty scale buildup that I might have accidentally knocked into the burner.
I haven’t taken the burner off or anything like that but I might 1 day to clean the nozzle, when I read more on how to do it ...but I am just concerned about that white smoke and it starts when after the burner fires the blower comes on and then the burner shuts off and the blower is still on then after 45 seconds after the burner shuts off and the blower keeps going the white smoke starts to pour out around the burner and wont stop until the blower finally shuts off...Any ideas? Thanks!!! “
Yup, it comes from the area where the fuel nozzle and electrodes are inserted. Everything is calibrated for 70/70a. The "smoke" filters back through that area and out the oil pump's air inlet dial. Since doing all the work, things are running fine minus the blow back smoke. It smells like kerosene cooking, not burning (if that makes sense)
BTW, this is NOT in the heating ducts. ONLY at the source. It is not dispensing throughout the home.
Thanks ETL..checking it out..
“Unless the furnace has a mechanical valve that opens when the pressure of the oil pump forces it open, and closes when the pump turns off. I say it’s not closing.”
That is how it works. It is part of the pump and the spring pressure on it is adjustable.
It most likely does not fit his description however, although his description is not complete.
The white smoke blowing out of the burner is his biggest clue as it suggests a real possibility that the exhaust can’t get out and that therefore the flame is not getting oxygen as well. Once the combustion chamber fills up with smoke then it actually smothers the flame. Once this happens then the light sensor will not receive enough light and the control will shut the burner off- requiring a manual reset.
GMTA...
And so do *ours* ! :-)
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