SERVICE CALL FROM HELL NO ONE CAN FIX IT
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- Опубликовано: 23 ноя 2024
- SERVICE CALL FROM HELL NO ONE CAN FIX IT
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I had an intermittent issue with my personal oil boiler, it would fail every week late at night on the coldest day. I would clean nozzle, points, check oil pressure and she would start right up. Only to fail again another night. One night I was pissed and came down and kicked it again it started right up. It was a relay on the control, cracked solder joint. I soldered it that night and it's been good for 10 years since.. Hate intermittent issues they make you loose your cool sometimes...
I ran into the same thing on mine. Transformer on control board had bad solder connection. Resoldered and haven't had any problems since.
That's exactly what I think the problem is, the soldered terminals where the relay is connected to the aquastat board. that relay snaps in rapidly cracking the solder over time. I've seen this many times.
Had the same cold solder joint problem on my Audi's main engine ECU relay, always running fine when cold or hot, and lots of missing in between. Finally found the relay after _lots_ of fault search, and it's been great since! Hate cold solders, but they're always a blast to finally fix! :D
Hey Steve. Love your vids. I worked in avionics and had a similar problem. A unit was intermittently losing power. I would put my voltage probe on a terminal on a circuit board and the unit would power up. Took the probe off and would lose power. Found that the circuit card had a cracked run on the back. By taking a reading on the terminal, the pressure from me holding the probe on the terminal was causing the crack to close up and making contact, allowing power to resume. Oh what fun electronics. You do great troubleshooting and diagnosing.
Bingo, exactly!!! Cracked circuit board trace, and this can be caused by overtightening the lugs on the backplane. So gotta be careful not to overtighten.
You are correct. I had that exact aquastat with the same problem. It had a bad solder joint on the relay. Just resoldered and was good.
That’s what I was thinking, just the way you put pressure on the Circuit board it was acting like the traces were delaminating and/or a failed solder joint.
Solder on the in the back of the circuit board had a crack in it . Which would give an on off reaction when pressed or looped . Because it only made an electrical loop with a jumper wire applied . Chances are the component will need to be replace to stop the error .
You were making a circuit with your meter connnecting it basically feeding it power
Jail a/c where I work would periodically go into free cooling mode even though it is not set up with free cooling (option on motherboard) Turn off power then back on. It would sometimes run 2 to 6 weeks and sometimes it would go back into free cooling before I even got home. I had tech out several times over a 2 year period. I called owner one day and asked if he could take a look at it. He was semi retired at the time but a top notch tech. We turned unit off and back on and waited for time delay. Unit kicked on and we heard a arc sound. No.1 fan stopped and went into reverse , tripped on high limit and went into free cooling. Found a wire that had a tiny nick in it and it would occasionally make contact with metal bottom. Fixed that and all has been good. That was the first time it had done that while standing there. It sometimes did it several times in a month and other times every other month or so. Great vid Steven!
Bad wiring connection. Could have also been a cracked solder joint that holds the wire terminal to the circuit board.
Right! When I saw him remove the probe pressing against the printed wiring board and heard the motor stop, I was also thinking of a cracked printer wiring conductor path on the PWB near the probe point.
You'll be back there. No way was that intermittent problem caused by the wire going from the limit switch box to the burner. You were measuring the voltage at the feed end of the wire and it was dropping out there, how could it be the wire causing the problem? It's pretty obvious that the problem is an intermittent connection in the limit switch box because when you would make physical contact connecting and disconnecting your meter, the voltage would come and go. The problem is most likely a bad solder connection on the backside of the circuit board in that box. Probably the connection where you were connecting your meter.
Yep. Worse thing ever is trying to fix an intermittent issue while somebody looks over your shoulder. I was surprised he didn't do electrical checks before replacing any parts. Likely nothing was wrong with the pump. Was only getting power intermittently too. He DID find several minor issues with loose connections though.
Yep, good observation -- meter probe pressing on the hot contact in the limit switch box and then line voltage drops out when probe removed. Probably that ckt board / weak solder joint.
Electronic tech here. I'll also bet it's a cracked solder joint where that terminal solders to the PC board or something else on the board has a bad solder joint. Or it could be a cracked copper trace on the board. Either one is easily repairable but time is money so I would understand just replacing the entire limit control.
@@andydelle4509 Yeah, I agree. I'm just surprised he didn't catch that. But then, there are so many aspects to HVAC servicing, you can't be an expert on everything. None the less, I've learned a lot from Steve's videos.
@@gailtaylor1636 Steve is highly competent but we have all had one of those days where we totally miss the obvious. And with what he went through there, we'll cut him a break!
If it comes back in again check the back of that controller board for cracked solder joints.
Yes. I came to comment the same thing. The symptoms were consistent with a cold solder joint. Pressing on the board with his probe flexed it enough to restore contact for a while. Lead-free solder and vibration make this problem more common.
With vibration brittle solder is more problematic for board connections or in itself ,🤔👍✌️💎
Good hearted and honest repair technicians are rare. This guy is awesome! Puppy is wonderful too!
Interesting vid Steve! Had an interesting one years ago, milk cooler would cut out, no display, by the time we got there it was working again, turned out the sun was shining through the window and warming the controller up which had a bad solder joint! Took a few visits to find.
hello heavydiesal hope your doing well my friend
@@stevenlavimoniere Doing ok thanks!
what i was thinking when when he kept moving his probe
I thought cold solder joint too,worth pulling board out and running soldering iron over wiring before relay as I hear it click off so power loss so try circuit before relay
Im a factory rep for a refrigeration manufacturer and we have several controllers that will blank a display when there is a short connected to the controller. Usually it's a thermistor, but sometimes it's the condenser circuit or a loose neutral. Danfoss is notorious for doing this. You can test this by leaving only L and N hooked up and if that's the issue, the screen will turn back on. I see this a lot. Did you actually open the control, thats a lot further than most techs would do. They usually just tell me its "broke" lol.
I really hate intermittent equipment problems. Willy nilly parts swapping and having some customers think it's amature day is no fun mamma!
In such instances I do my best to educate the consumer and they either get it or they don't. Nothing more one can do. We're not magicians or gods, just human :)
Oh man you described it perfectly!
Electronic transformers were supposed to be the bomb. Yeah right one leg dies intermittently and drives everyone up a tree. Sometimes the old school ones are better, because when they get weak they die no guesswork.
can not fix what is not broken at the time. that's why i tell people to take video
Could be a cracked solder connection on the circuit board causing an intermittent. That would explain the odd voltage drops you were seeing.
Yes , I agree.
Aka cold solder joint. I am a electronics tech for over 30 years. Course could also be an intermittent short in wires to control.
@@madusan1 Cold solder joints...they'll bite you in the ass every time. Just a matter of when.
Yup
yes pull the board and reflow the connections this has happend to me,
Hi Steve, what fun your having ! All these limit sensors are daisy chained together ! Ran into a similar problem with a natural gas furnace years ago, turned out to be the high limit sensor was intermittent!!, funny thing is that the rest of the crew in the shop couldn't figure it out and gave up ! Boss wasn't too happy with them, but my work partner and I were able to find the problem and fix it ! Great video
Nice!!
Alot get the money and run out there! Guy won't answer now! You have to see through hard repairs because you learn from them and it makes your job easier in the long run! Great trouble shooting as usual Steve!
Hi Steve, watching this video reminded me of the same problem I had with a new heater I had installed 7 years ago. one day the heater stopped working, turned out to be a bad connection in the same wiring you had. If the cable was hanging down just a little the system would shut off. I had to zip tie the bx cable up to support it. The guy who installed the system said he has had problems with the same cable. Said he would come back out and fix the problem, asked him many times to replace the cable, never came back. after 7 years the zip tie is holding the cable in place and it works. Never again referred him to anybody.
one of my favorite vids from steve. if im trouble shooting anything, i check connections first and do some wire wiggling. it may take a little longer but its cheaper than firing the parts cannon plus then you know you got the problem fixed.
anyone who doesnt test first and just starts changing parts is an idiot.
I had that same problem on my boiler limit contol, and it was a bad solder joint on the back of the board. I think I replaced it just because I had no faith in the part anymore. If I remember right it did some damage to the relay for the burner.. I remember checking it with a meter and it would work just like he had. Definitely a suck call.
As for the wire theory...completely plausible.. I had a piece of wire open mid length in a covered conduit. I only found it because it failed long enough to find it. Depending on how you moved the wire it would make up again. Between the two possibilities, the solder joint would seem more likely. Time will always tell.
Thanks for the content, I've learned a lot about burners.
I’m gonna go out on the limb and say whoever replaced fuel pump did not or forgot to set the pump pressure to 140psi. Pumps come set at 100. You do know with that control you put on if you hold down all 3 buttons you can configure the t&t terminal to on so you won’t need a jumper.
The air band looks completely shut. No good
If she ain't getting it from the air band, she's getting it from a lose gasket
i worked on broken equipment for 50 years and some of the stuff you see is bizarre. I once had an intermittent problem and it was a lug that was crimped on the insulation at the factory, not the bare wire. It worked for months but as it aged the crimp got just a bit weak and it lost contact with the wire, strip the wire end and a new lug and life was good.
Another good one is the wire that goes but never gets there, it's a wire defect where there's a tiny gap in the wire conductor under the insulation. Moving the wire can make it come and go, replace the wire and all is good.
And then there is the cracked solder joint that can drive you nuts.
BTW RUclips is going crazy with ads - good way to drive people away.
I spend more time watching RUclips than TV & sleeping. So the 11.99 for no ads is worth it for me.
Great video, worked on cars a long time , learned how to work on my boiler from watching my plumber, next time check for continuity I was thinking of a short when I saw the voltage drop.
Steve, it might be that the power from the circuit breaker is intermittent. The stabs on the breaker might be loose or burnt on the panel buss. Check the breaker connection. Good luck!
Loose electrical wires can be a nightmare or a loose connection on the circuit board . Good job Steve and miss molley
Most electrical problems are easy, its finding the problem is the hard part and as an electrician for many years I find that they never just go away it always comes back.
Under normal operation with lack of air entering into the tigerloop, its lower chamber will fill up with oil and when air enters via the feed line the lower chamber will drain.
I believe that you were losing a neutral in your motor supply whip. Great troubleshooting Steve. Yous the man.
Like someone else said in the comments, I bet it's a cracked solder joint on the back of that control board. Slight temperature variations, vibrations, touching the board with meter probes .. all makes sense. One minute with a solder gun would fix it right up if this is the case.
That was interesting alright. Now, how would you like to troubleshoot an autopilot on a twin engine airplane? BTW, I learned enough for you to install a mobile home furnace in the second floor of my workshop, blowing down through the proper mobile home base. Then, when I had trouble keeping it running I found out about a tiger loop from you. My oil tank is at the 8-9 foot low limit on the first floor level. Ever since I installed the loop, it has been working flawlessly. I can change, adjust or troubleshoot any part of the system after your informative videos. Thanks Steven, from central PA.
Not unusual for tiger loop to go full if there is no air in system and the tank is above oil burner. Gravity feed systems will always fill tiger loops. Oil safety valves will stop that from happening.
Also, watch tiger loop video. Tells you is ok to run with bottom bowl full of oil.
Thank you for all your HVAC videos its helping me in school
Intermittent things are easier to fix when they stay broken!
Than they wouldn't be called intermittent, would they...
No joke, ive got 2 intermittent issues with my truck. Wipers sometimes run until they decide they are finished and i have a completely random misfire when going 60+ mph.
My newer steam boiler had a wire problem between the low water cut out and that relay box. The solid core wire had a nick in the insulation. Took we quite a while to figure that one out... Intermittent problems...
This was like me diagnosing my outboard engine. Went through all sorts of electrical, ended up the carburetor needle seat vibrated loose in one of the carbs. Sprayed gas in the carb and the boat took off!
Class act Steve. Taking care of that guy and not killing him on labor. This is the type of situation that not only is the right thing to do, but will earn you a loyal customer for life who will tell his friends and family about your integrity and professionalism. Young techs should take notice of this, because this is how its done.
I'm a new (not young lol) tech and I'm paying close attention. This fella clearly knows what he's doing.
@@TheRubtastic knowledge is power. If you could diagnose and fix anything you make more money because you are worth it.
Agreed. I see a master veteran tradie in the flesh. I'm a carpenter that's been around. Guys like this.. Are a Rare breed and great to watch and learn from.
Parts today are not reliable. When boiler lit off you had oil in chamber so I found the best to do is reset boiler with peep site open
When boiler lights off count to 5 and shut off look for after burn from missed ignition. These new igniters are not transformers and suffer from intermittent fails, new igniter solves problem. Good video
Hi, Gas registered gas engineer from the UK here. What I see is a dry solder joint on the back of the printed circuit board which connects the screw connector. I've had a few of these, more often when a higher current passes through the joint. Regards from the UK.
That model aqua stat has a higher fail rate than most others in my experience. I’ve had them fail and keep running wild making steam popping relief. Not cool.
@Steven Lavimoniere I don’t think you fixed this problem. I think you have a bad solder joint on that over limit board. The bad joint will be on the lug that is used to connect the wire to the pump. This is why it worked when you put your meter on it. The pressure of you pushing your meter leads temporarily helped it make contact.
I agree. Sounds like a cold solder joint that cracked on the board.
I’m not gonna charge you for this labor, or for this. Customers like, geez buddy I don’t think you should charge me anything, you’ve replaced every part and you still don’t know what the problem is. This is what we call Grasping for straws diagnosis.
Steven, you fix things as well as teach the customers. Great. 👏🏾👏🏼👍
Thanks for the insight Steven, I got backed into a corner with this gas boiler a Friend came out and said you need a vent damper. Well okay I'll give it a shot looks easy set it up and it closed never to open. So after a few days when my feet were icicles, I went down and traced the wires I pushed on the black wire inside the aqua-stat suddenly the vent damper open and the burner fired. So yes I put on my Hawaiian shirt and made a Pina-colada. Loose wire was the problem! Watch out for loose wires and loose woman and everything will be fine Thanks for the video's The Skulmonkeyz 🤣
I had the exact same problem, with the exact same burner and transformer, it would run perfect for a few weeks, then lockout, hit the reset and tap on the transformer (new less than a year old, came with new burner) and it would fire up for a few more weeks. Replaced transformer problem solved. At first they thought cad cell, and replaced it which didn't fix it, but my service guy is really good and figured we'd try that first before the transformer, being an intermittent problem I couldn't make it fail when he had time to come out, and of course it was in the middle of winter and couldn't leave it off, mama don't like the cold.
Cold solder joint on the board connection that was getting probed by your black lead @ 49 minute mark. Cold solder joints are intermittent as hell, and can cause callbacks. You had positive cause and effect when you were probing the connector, when you applied pressure through the probe the connection was positive, removing the probe caused it to be flakey. Resoldering that board connector would be a decent repair, or replace that limiter board altogether.
I’m glad I’m not the only one who runs into this shit sometimes!
This video was full of useful info.!! I am having a similar problem with my furnace, thanks! That controller with the diagnostic readout was amazing! I did not know they existed.
Good golly ! Miss Molly !
Love that puppy. Once Steve sent me out to his truck to grab a couple filters for my attic unit. He didnt tell me about the (loud and protective) chihuahua he had at that time. Scared the living crap out of me. It was hilarious ! He's the best.
Electronic transformers start to cook from the day they are put in. It’s even faster to fail under the cabinets Burnham put on the burners to deaden the sound. Until it fails completely, you get a no heat call. You ge get there and push the reset. The burner starts and won’t fail because it cooled down while you are on your way. Sometimes it will work for a day. Sometimes a week after you leave. Then, another nuisance call back.
And now, quality control being what it isn’t, I’ve heard of a few doing it brand new
Intermittent electrical problems are the worst, gaint time suck, but it feels good when you finally figure it out. Way to stick on it!👏👏👏
I fix propane heaters at work, always having bad connections since they're in harsh environments. One thing i like about them, if they stay running nothing's wrong, all is good. If they don't, they have a problem. ONE bad connection and they'll shut down, so then i gotta find it, otherwise it's a bad part. They're fail safe, they either work right or they don't work at all. I've fixed them so many times, i can generally go right to the problem depending on the symptoms.
You will only see movement in the Tigerloop if theres air.
guaranteed crack in a solder joint on the back of the aquastat! Had a brand new one crack when tucking the wires (heavygauge) in to put the cover on...what a nightmare!! But once you've seen it, you recognize it fairly easily the next time
WOW...Mr Steve is a true technician
He got lucky the issue appeared while you were looking at it. Hopefully was just a bad wire, though a cold solder joint at the connector is also very possible.
Check the breaker going to the burner. Good fix I hope, Thanks for great video's.
When the voltage changes , Sometimes it's the contacts in the controls and relays that are bad , If the contacts are black they are shot and there is resistance across them .
Steve can fix anything and cooks a great stew too!
he likes snappa soup lol you tube captions go crazy trying to type what he is saying love the guy and his videos glad hes you tubing
Those Honeywell aquastats will develop cracked solder joints over time. They will be obvious upon close inspection, especially the underside of the board. A simple reflow with leaded solder and it will be back in service.
Excellent video. I liked your logic following the issues. I noticed that merely pressing your meter lead on the terminal and removing it duplicated the issue. If it wasn’t the connector at that point it is likely the circuit board. If the board is removed, I suspect you will see a blackened area on the backside of that board. Anything that makes and breaks a 120v connection will leave a carbon trail. I would be curious if you noticed any blackening with the connectors your replaced.
Steve nice job....
If happens again I'd replace that honeywell controller 👍
When you go back out a 7224u on and you should be check power at L1 in the aquastat not B1 it could be a breaker going bad also check the pump pressure and you have the hold down all 3 buttons on the primary control and you can set TT on so you don’t need the jumper
Great video Steve! You kept at it and didn't give up after 4 hours. Well done!
these kinda things separate the good from the next level mechanics...txs for sharing
I’m surprised to see an oil burner. Every house I’ve lived in has had natural gas for heat, when I moved out to the deserts of the west we have heat pumps. But I’ve only seen like two oil burners in my whole life and I am a senior citizen
always having problems with my t-ts ! Sometimes you just need a new pump, cuz when you pump ya t-ts, it relieves pressure on the connectors.
I have done Electrical work before and it is easy to Nick a wire in Conduit and Vibration from The Motor running can make it worse.
Fit a pressure gauge on the pump. Will stop you going around in circles
Do you like working on Boilers/Furnaces more or AC units?
i like them all . different seasons = different work
I had a very similar problem in a care home just outside ,London it would run for a week then cut out they would reset it and it would run for another week ,I changed the photo cell and the solenoid on the pump and it’s been ok since.
Cracked solder joint on the controller board is my guess, had the same thing happen on mine. Re-traced the solder connections at the relay and it’s been fine for years. I’ve found the same problem on other controller boards too, usually right at the relay pins.
Great call. Awesome homeowner and some great education. Thank you for everything you do.
Great job! You’re the man especially with oil fired equipment.
This was a good learning tool ... Good troubleshooting ... Thx for sharing ...
Thank you very much for the great video and you sharing you decades of skill with all of us. Great job.
Seemed like a cracked solder joint in the upper part. I noticed when you removed the one probe on the connector it shut off. It didn't seem like removing the neutral to the meter made any difference. Just the one probe to the module.
Nice logic. Tiger loop no circulation. Check the others dudes work before you blame component failure. Spot on . What a pro. Now that the mechanical issue seems to be resolved time to check what would cause the intermittent electrical failure. Voltage drop? What is causing it?
I hate oil burners. I worked with them years ago. Stinking with oilsmell when you get home from work. And the time it could take to search for the problem. But when you fixed the problem it was a rewarding feeling. I think maybe you have a cracked circuit board in the controller. Or a bad solder joint.
You are a real class act Steve, if I ever could pick a father it would be you.
Yeah, a "class act" that constantly drops f-bombs and such in front of all his customers. SMH
Steve, I had the same control give me these problems, ended up the hot terminal got hot and melted solder on connection and created intermittent connection.
I had a really weird one like this recently! Customer had an error code on Honeywell aquastat indicating an issue with the burner. Long story short, hours into the visit, we discovered he had bad voltage going to the aquastat from his circuit breaker! Way we figured it out was we plugged an external 120v power source into the aquastat and it fired right up. When I got into this trade I didn't know I'd have to be an electrician too!
Great job troubleshooting !
I had the exact same issue, and it was the main controller, replaced it and been good for 2 years now.
You need to cover the floor if your going to spill oil all over it. Oil system was fine to start with. I couldn't see if there was a low water cut off on the system, that could have been a problem as well. I think the 8148 will need to be replaced
Steve, really interesting problem, takes lots of experience to find the source of the problem !
It is my understanding there is no rhyme or reason to the appearance of the tiger loop see-through dome. Think I remember reading their literature and them mentioning that it just does stuff and will either be full, empty or anywhere in between during normal operation.
Is the pump pressure set at 140 psi as it states on the burner
Most of those pumps are set at 100 psi
Thanks for another great video !!! When in doubt, call Steve out !!!
Chasing electrical problems sucks. Nice job, Steve!
This guy is a real mechanic!!!! Top notch. Great job as usual Steve....
Had this happen before, it's a cracked solder joint on the back of the control circuit card. When you make contact with your prob it flexes just enough to make good contact. If it happens again change out that board.
I have a beckett running a hot water boiler in the farm house, does same thing RUNS FOR A WEEK OR 2, i have found over the years,it's a combo of things ,low temp of fuel causes reduced flow ,messed up nozzle spray pattern from too much dye in fuel and heat exchanger soots up because of the 1st issues, my oil guys could never get it to run right, I service it myself now ,i get 5 seasons from a nozzle if i clean it,they have a brass filter which clogs up,you can only tell its plugged by blowing thru it ,RE reduced flow its hard to blow thru otherwise you cant see anything, clean tip with break parts cleaner, and your good, Then pull out burner and run threaded rod thru the tubes in exchanger , vachume out burn chamber of all soot, just basic maintainence. I have done this for 15 seasons now ,it runs flawless, you know when its time for nozzle clean when you see an un even burn looking thru sight grass,the big thing is the dam dye sets off all of the flow issues,I had 1 tank a few years ago the oil looked like blood, the unit would only run for 2 days before the nozzle was crapped up ,so always check your fuel quality.
I think your voltage drop could be coming from the ckt. Board relay. Test the relay replace it for $10. Or less its a cheap part but requires a moderate soldering skill.
Thanks for filming, editing, & uploading as usual! We appreciate it. Interesting job and nice work! Loose electrical connection can be a headache to figure out. Loose neutrals can be a bitch and dangerous too.
Yeah, definitely a good one. It's a good thing ya stuck with it till the end, that's what it takes. We all know some have limits, they get scared cause they think its gonna be too much work and the customer won't pay and all so they bail before they get too deep in the hole. You called the bluff, good call ! Good job, I hope its not haunted .
Observation. Test crap out and prove its bad. Part swapping for many is just a bad habit. Sometimes it is the last choice not the first. Like one time troubleshoot leak through ceiling. Plumbing or show pan bad. So I filled water in shower pan and put some blue toilet bowl clean in the water. Well blue water leaking down stairs. No guesswork the test pass or fail.
Love your invaluable troubleshooting , talking to Miss Molly and you swearing with your New York accent.
I used to hate calls like this. Leave the house Boiler is running fine and an hour later customer calls and says "I got no heat again " ...DAMN !!!
solder joint on boiler control at the terminal needs to be resoldered its got a cold joint and it will cause intermittent problem and high resistant joint causing voltage low
Blow out the supply line from the tank. It can clog. Is it close to the bottom? If so it will pick up sludge that can take 90 lbs of air pressure or more to clear.
so if i see this right the tiger loop is a carburetor basically fuel comes in the main line the float shuts off the main lain when its full to the bottom of float then the rest circulates through the lines to the burner when its empty enough to let the float down it lets more fuel in edit: wonder if it was full cause the float in the tiger loop maybe not closing all the way
If you look at the diagram of it the float in the lower chamber closes off the vent port to the upper chamber to keep oil out of the upper chamber. My tiger loop has been maintaining pretty much a full lower chamber and from what I've read in the manual it's completely normal for it to be ful or almost empty. If it bothers you they say installing a prv or check valve on the supply lowers the level because it doesn't allow oil to flow as easily until it starts pulling vacuum
Steve, did you program the primary control after you installed it? Should be setup for boiler, delay valve and internal jumper.
More than likely on the back (trace side) of the circuit board, as others have said a broken trace, a cold solder joint or a broken solder joint, each of those will cause the intermittent problem. Just the slight pressure of the VOM probe closes the break. Also just small changes in temperature can cause a thermal opening, either from the heat of the boiler or current flowing on the circuit, the thermal heating can cause it to open, when it cools down the connection closes again.
Have solved for this same problem many times on many industrial machines and avionics equipment, especially stuff that vibrates! Intermittent is always harder to find.
We had a new Trane gas pack roof install that was from Hell, 4 technicians had come out 4 times and replaced everything on the furnace and every morning it was locked out but it ran fine util the morning. I was sent out as I was the troubleshooter, I sat o the roof from 6 pm until 1030 pm watching the furnace cycle normally 50 times, I was starting to wonder wth it could be when suddenly the furnace locked out, I yelled inside, what did you just do?
The owner said I turned the temperature down as I do every night before bed, I tested it and sure enough the thermostat had a short when depressing the down temperature button.
I like these long videos. Great job diagnosing!