Normally I use a knife to clean the dark coating off of wires before I hook them up. Certainly before I solder them but even when using screws or wire nuts.
Tonight I replaced the primary controller on my oil furnace and because my work bench is only a foot from the furnace and so it was awkward to get to the wires, and because today my back was sure to start hurting in 10 or 20 minutes, I skipped that part.
Bad connections were not part of the previous problem. I tightened the screws firmly. The furnace is working fine. Still, is it likely that a bad connection will arise in the future because I didnt' scrape the wires???
When summer comes, I can redo it, pausing whenever need be if my back is still hurting.
There are 4 wires from the thermostat, 2 wires from the cadmium flame sensor, 2 from the fan relay coil, and 2 to the compressor contactor coil, all 24-volt.
The next 2 questions might require experience with oil furnaces:
2) The diagram of the inside of the controller shows a "solid state switch" but the one in my old controller was mechanical**. Clear plastic cover showing contact pins like a relay, some little round thing (looks like a little motor but isn't), and some other stuff (it's in the basement. I'll give more details if you think it will help.)
**Except maybe for the solid state heater, which is part of its timer
This is the device with the red reset button, that trips if the furnace runs without a flame. And this's the part that failed this time. Normally one just pushes the button once and, sometimes after waiting 2 minutes, the furnace starts up again. But Monday, it was necessary to press the button usually 5 or 6 times, later in the week up to 30 times, and then, every time the house was warm enough for the furnace to turn off, it wouldn't restart automatically. I had to go press that button again. The thing on occasion makes 2 or 3 different clicking sounds, one after some timer somewhere, and one when it's ready to reset, and maybe one when it actually connects and starts the furnace.
Does this thing have a name besides "solid state switch", especially since most or all of it is mechanical??? Or where could I learn more about it??
3) I bought the new controller, used, because it was an exact replacement for the one that was there, including the extra terminal, and it was only 75 miles from here, but I could have bought similar, NEW, for even less money! The big difference is the safety delay (lock out) time. That is the length of time the furnace can spray oil into the firebox without a flame before it turns off? Therefore, is the proper time that definite? The flame start within 3 seconds almost always, and if not always, then within 8 seconds the rest of the time. So should it use a 15-second delay, or do they use a 30-second delay just so the furnace will still work when it's having a bit of trouble sterting?*** Or are there furnaces that don't light for 20 seconds? ***If this is the reason why not wait 45 seconds?
Oil sprayed but not burnt is disposed of iiuc by dropping some sort of flare (what are they called?) in the bottom of the firebox, where it burns off the excess oil. Though iiuc, the oil can sit there for years without causing tremendous problems. ???
This one is new, but it's 45 seconds: https://www.supplyhouse.com/ICM-Controls-ICM1503-ICM1503-Intermittent-Ignition-Oil-Primary-Control-Safety-Timing-45-Seconds
For completeness, nothing you really need here: https://s3.amazonaws.com/s3.supplyhouse.com/manuals/1266604962353/26555_PROD_FILE.pdf
4) Even though it was only 75 miles from here, its delivery path was surprising. (It met its predicted arrival day.) Xmas I noticed house was cold and also I had to press reset more than once. 2 hours later, bought replacement on ebay. 5PM Xmas, email says it's shipped (although that usually just means the paperwork was done). Still, it was in Quakertown by 2PM Tuesday and Philadelphia by 10PM.
Could easily get to Baltimore, 70 miles away, by Thursday (maybe even Wednesday), but instead goes to Rochester NY on Wednesday, Hyattsville Md on Thursday, and Baltimore on Friday. Of couse Rochester is 100's of miles in the opposite direction. I don't know if this was the plan, a fluke, or an error in the routing database. ??? I'm not going to complain but I will write them in case they don't know they're doing this.