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??
Will no one rid us of this turbulent furnace?
A leaky valve could be easily checked though- just look inside and see if the ‘gunk’ he removed has returned.
I had a similar problem last month but I have a boiler. Smoke was coming out and it smelled like fuel. That’s what alerted me to there being a problem. I turned off the boiler and called the plumber. He changed the blower. He said that “something” was misaligned and it wasn’t shooting the fuel straight but at an angle and that caused fuel to accumulate in the blower and boiler. There was also a bit of fuel which had leaked on the floor right under the blower. Whatever fuel was in the boiler had to be burnt off before the flame was clean.
He did have to clean the boiler because there was a lot of soot. The boiler had been cleaned in Nov.
“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)”
I was under the impression that it always shuts down after several seconds. And that is when you get the smoke. If not then that could change things. With only partial exhaust restriction the burner will keep running but exhaust will back up.
Then there is the matter of knowing what a properly burning flame looks like. And I still can’t imagine not having a safety control using an electric eye. So I guess I will bow out.
I think you are onto it; bad draft and the blower kicking it back out.. My many thanks for the link and subsequent. Going to tear some stuff out now looking as the home is warm!! :)
Call a professional furnace repair guy who actually knows something - else it could get very expensive very fast.
^ This + 1 except this could be a dangerous situation. The white smoke may be vaporized fuel. It sounds to me as if the transformer is shutting down before the burner motor allowing fuel to enter the combustion chamber. If fuel were to pool in the burner chamber, on the next ignition cycle bad things can happen. Call a pro ASAP.
You sound like a good technical guy. If you judge that this condition is not causing a hazard (like fuel puddling or creeping out the furnace) wait for an oil burner guy to check it out. Diagnosing one of these is usually not that bad, but getting one tuned properly is not trivial, even for a technical person.
I have tuned many, many oil burners and it’s not easy.
If you think that there is a hazard, I’d call a 24 hour oil burner guy and pay him to get it firing properly.
I understand that you are moving soon, so you may want to have the oil burner guy do an inspection while he is there, so you don’t need to call again.
Well, it wasn't my info. It was stuff at that link. I actually would advise you to at least talk to some pros before messing around too much with it.
If it has an electric coil operated cartrage type shut off near or on the pump, pull the cartrage out and look at the O rings for damage. Sounds like it dribbles like when you think your done peeing and you reel it on in and your glad your’re wearing your shorts.
Bad O rings is like the valve not being shut off all the way. Valve seat bad or spool rod stuck...same thing.
Some nozzle atomizor tips also have check valve to shut off the drip.
My experiencd is on construction heaters ...big and small.
I’m an all around mechanic, very dangerous to be one.
Probably post of the week.
" It was later determined that two rubber O-rings, which had been designed to separate the sections of the rocket booster, had failed due to cold temperatures on the morning of the launch. The tragedy and its aftermath received extensive media coverage and prompted NASA to temporarily suspend all shuttle missions."
Lol!
White smoke is steam so maybe condensation is boiling off. Drain needs cleaning?
Who not decide what manufacturer to google, then search for your problem. At that step you’ll no doubt have the solution to your problem.
Posting problems on the FR website will never be as effective as if you searched the internet for a resolution. Besides, you wouldn’t be taking up valuable time while we attempt to solve the problems of a nation and a world descending into the pit of iniquity.
Further, you won’t take our busy time spent solving the world’s problem and using up band space.
Now, it was never my intent to piss you off and make you feel as though I am a bad old baddie.
Back to the old method eh?
Wife and/or girlfriend out of town.
I concur, get a pro. I had a premature shutoff and the internal reset button didn’t help (that sounds like what yours is doing) and my furnace guy pulled apart the igniter assembly, swapped out a plastic part (he happened to have the right size in his truck), and it fired right up, no recurrence 18 months later. $100.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.