I Have an oil fired heater. This box that is attached to the flue keeps on tripping off the heater (a thermocouple, right?). I have to keep on pressing the reset button on this box to keep the furnace going.
I’d like to replace this box, but since I don’t even know what this gizmo’s name even is, I can’t really do a google search.
It’s made by Honeywell, but I don’t see any kind of part number or other identification on it.
That box may be working the way it is suppose to, and it is shutting down the system because of another failure in the system. My WAG is that the nozel is clogged (should be replaced once every 1-2 years anyway), causing poor combustion.
I just had the blower and injector assembly serviced last week.
I think the thermocouple(?) box is worn out…that happened about 15-20 years ago.
I just adjusted the thermocouple part…the part that actually sticks into the exhaust stream of the flue. Pulled it out of the stream about an inch, so it dosen’t get the full brunt of the heat. That now keeps the heater from tripping off every few minuites, now.
This isn’t a good fix, I know. I need a replacement part.
I don’t know about the specific arrangement of your furnace, but generally speaking, a thermocouple is the device used to “prove the flame”, that is, it generates a signal to let the gas or oil valve know that the flame is lit. If the thermocouple does not sense flame, the fuel valve shuts off. If the device you are talking about is shutting off from too much heat, it is most likely a high limit thermostat and the device you moved is a remote sensing bulb. It is possible that the safety has gotten weak and trips at a lower temperature than it should, or it is possible that your flue gasses really are too hot. If you have an oven thermometer or other means of measuring the flue temperature, you can check it against the stated limits on the safety. You can also get the part number from the safety and look it up on Honeywell’s website, then Google or call around to find out what a replacement will cost you.
Most importantly, defeating the safety to keep the furnace operating is an EXTREMELY dangerous thing to do!!! I cannot over-emphasize this point. Unless you have absolute unassailable proof that your unit is safe to operate, DON’T! Get this fixed immediately!!!
BINGO—Rhubarb
What I would have said.
I service HVAC equipment for a living. (as well as designing systems, installing them, selling them etc) I have given a fair amount of advice here on related topics.
If there is any type of [residiential] equipment that I would classify as Do Not Try This At Home, it’s oil fired appliances.
My advice to you.
1)Stop
2)Call a qualified service technician, making sure to insist that the service technician that they send be a journeyman in servicing oil fired appliances. Better yet, find an HVAC firm that kind of makes a specialty of it.
Oil fired units do not use thermocouples, in the same fasion as NG/LP units. They “shoot” atomized oil that is burned through a combustion process that is too technical to get into on a message board.
Hitting the reset button continuously is a [potentially] dangerous practice. (for the purpose of this post, feel free to consider ‘dangerous’ to mean [substantial] property loss, or loss of life)
It is also unwise to simply change parts on a hunch. Further, oil units are **much **more specific in setting them up correctly. Your guess may be right (although I doubt it) but you may end up with a unit that is running poorly or dangerously.
As Rhubarb mentioned, the part may be doing it’s job. Your temporary fix may have put this unit, as we speak, in an unsafe condition. * In fact, it’s likely.*
I think Rhubarb gave you good information, but I would disagree on one important point: You’re not qualified to diagnose, repair or set this unit up correctly. More importantly, this type of equipment is not something you should guess at.
(This from a guy who admires DIYers, and who is glad to offer step-by-step help)
Hate to say it, but I think you need to call a skilled technician, and make sure they make the repair and do a combustion analasys when they’re done.
Oh those old time memories-------
(AND NEVER TRUST THE CUSTOMER FOR HONESTY)
I remember one time so many years ago on a gun fired oil furnace complaint for “no heat”-----------Asked the custormer how many times he had pushed the reset button on the primary. Said “Oh maybe a couple of times”
Silly me I believed him. --------
Did not check the pot for excess fuel inside. Fixed the unit and fired it up.
OH OH OH ------what fun to be had!!!
The furnace started rocking. And then it started rolling. And then it seemed the furnace room started to move.
Should I call the fire department?
I opened up the draft wide open to kill the flame at least a little bit----as us Sears techs were trained to do----but the whole thing was seriously scary. So scary I ran outside to see what was happening.
Outside was a wonderland of black soot going everywhere, all over the neighborhood (burn offs are not nice to watch you know)
All those pretty and very white houses for blocks around all getting covered with immoverable soot (well it actually is removeable-----just takes an awful long while)
Furnace finally burned itself out.
Was waiting expectantly the next day to be called into the highest service office at Sears to explain how I had caused them to pay for $100,000 worth of cleaning and repainting in that neighborhood.-------------
Never heard a thing about it. Maybe the neighbors figured it was acid rain or some damned thing.
Anyway-----I kept my job. And I learned —
NEVER TRUST A CUSTOMER TO BE HONEST-
It’s been quite a few years since I worked on this type of equipment, but I suspect device in your flue has a double function. It certainly is designed to cut the burner off if it does not detect heat within a few seconds and it may also be designed to shut the burner down if it detects too high a temp.
Since you say you just had it serviced last week, I’m suspicious.
If it were me, I think I would call another service company, preferably one who advertises specializing in the brand name on your furnace and/or burner. I’d ask them to diagnose the problem and also document any improper work that may have been done by the previous serviceman.
As others have said, this is not the place for DIY unless you’re experienced in oil burners and related controll devices.
For the amount of fuel in that sucker gun fired oil furnace -----------to cause that much of a burn-off--------He had to have pushed that reset at least 10 times.
Question is --------why do customers lie (or fib if you want) to techs? Who are just out there doing a job?
Don’t they realize that their house could burn down if they don’t tell (to the tech)the truth and the whole truth and nothing but the truth?
Techs are not psychology majors. We know how to repair shit. And that should be all that we have to know.
Only after the fact do we learn that you may lie sometimes to cover your ass for some silly reason or other known only to you.
Is it really worth burning your house down over-------for your ego?
What I am getting at here-----for all you consumers out there------
PLEASE do not lie to the tech who is coming to your house to fix something.
Lie to your spouse if you want to. Lie to your girl friend about your spouse if you want to. Lie to anybody you want to-------your boss, your co-workers-----
But PLEASE PLEASE -----
-------Do not lie to the poor repair tech who comes to your house to fix some damned thing or other.
Honestly -----he could give a shit about your personal problems with your wife or husband or SO or your boss—or your personal ego problems.
All he wants is the best info you can give him to fix whatever is wrong with anything. And he will forget everything that happens today ------tomorrow.
That is the only way repair techs survive.
Probably not real smart to lie to your doctor or your lawyer either.