2nd Call Back on a Hot Air Furnace 

I like OEM boards. I use universal to get heat temporarily until I can return. Being a Service Tech you want to have options on nights, weekends and holidays.

2 reasons you can be measuring partial voltage at the gas valve wires(assuming this is AC). Just wires being in close proximity can capacitively induce a voltage in the other wire. Try wrapping an inch of live wire in aluminum foil and you'll read a voltage on the foil to ground as an experiment. Another, in AC switching circuits a "snubber" could be across the relay contacts which suppresses the sparking and extends relay life but at cost of a really small current constantly passing through the relay. Moral of the story, always verify voltage with the load connected cause that will put a load on the circuit and prevent these wack partial readings :)

im not sure if you fixed it, but i would take a combustion test to make sure the pressure switch was working and doing its job. also the whole "14volts" thing, you could get that reading if common isnt getting grounded to unit. voltage is potential difference, you may indeed have 24 volts from r to c, but have 14 volts from the gas valve to ground because that ground isn't getting a true connection from the common wire back to the transformer. next time, take the reading from the gas valve to the true common on the transformer, not the ground. some manufacturers design units differently, and may not have grounded low voltage side. hope this helps.

On those electronic t stats , check across R and W on a call for heat and while in standby.. Sometimes you get a power drop across the stat and it may not send 24V back down to furnace board, ( say 14 V) The board is looking for 24V and if it is , say 14V , may work erratically, or as some mixed up old serviceman once said, your furnace is working erotically.... have fun...

Would your JL3KM2 manometer read if a pressure switch opens or closes on power? I have an SDMN5 and when troubleshooting I find the reading confirms the failure if tested... Man, I just got my Red Seal tickets for plumbing and gasfitting and feel proud. I will say, I can't hold a candle to how effective your skillz are. Truly admire your talent and thoroughness and find your videos very well done. Pro Tip, don't put poo in your eyehole. You'll get the stinkpie e'ry time 🤣🤣🤣🤣🤣 Seriously, heal well and stay healthy 💪

Pressure switch have to read voltage after the inducer run for few seconds then you can use the jumper. If you do it before the inducer run you get an error of pressure switch close

Safety first.

You should test for continuity accross pressure switch. Usually switch has just hot leg going through so if you measure across is you should have 0 volts. Both sides to ground should have 24v. If bad youll have 24v on one side and 0 on the other to ground. Easy way just bypass pressure switch and test for continuity across it.

Check the flame sensor return path for sold and stable continuity. Interment flame ground can cause interment flame failures

Give me furnaces all day every day. I can knock 10 out and be home at a decent time. Boilers can ruin your whole schedule.

So you're just an apprentice? Youre way more switched on than the majority of journeyman i've worked with lol

Even people with experience get call backs

Keep a bunch of different pressure switches on your truck so you don't have to waste your time going to Johnstone or universal or whatever other supply house you go to. They're known to go bad and that will drive you crazy.

i still find the having gas station attendents to fuel your car as crazy. of course ive always lived in areas where those were rare if you were lucky to find one and they are often treated as a novelty thing. because ive stood outside in the cold and fueled my own damn gas my whole life lol.

👍🤙

Sometimes they read correctly but they won’t work when trying to fire the furnace they can mislead you very easily if you haven’t come across it a few times I get calls all the time when the client says I had three different contractors and no one could figure it out

You know NJ is the last hold out on full service gas. I guess that the other 49 states don't care about the dangers of putting gas into your own car! 🤠👍 I guess the gas filler's union is strong in NJ legislature. 🤷‍♂

Should read 0 ohms across any switch.

Lol @ the coffee being the EXACT same color / tint / hue as the discharge water from an old boiler. :p Those automated coffee machine are gross, they cant be cleaned and they either are not or cannot even be rinsed properly. :P !

Those pressure switches stink. It would be reading 24v because the switch isn’t closed it’s a switch not a load. Meter reads the difference between voltage. The 14v I had the same weird thing then when I connected it to gas valve voltage went to 0 supervisor said there’s really no voltage there. Gotta be careful with that because I’ve said bad gas valve checked got 24v to gas valve with wires off then when I attached them 0v. Some boards have something that if the voltage is under load voltage falls to 0 and it’s really the board. Easy way to check is use a contactor if it pulls in it’s the valve if it doesn’t it’s the board.

i stopped messing with oil burners,it's just filthy and stinky ,not for me

First of all great video, just tell it like it is and be honest. Now days with all the new equipment coming out were all going to be apprentice's in one area or another. If you say that you never have problems your'e just lying to your self, and there are a lot of people on RU-vid that do just that. Couple other things, on some manufactures if you disconnect the low voltage form the gas valve you may not read 24 volts , and I never use universal control boards or anything that says universal, I learned my less on with Lennox and Rheem finances. Also I noticed that it looked like someone installed an AD-A-Wire. Remove it and see if the problem goes away, I've nothing but problems with that crap. Most of all be yourself and do not lookup to anyone on RU-vid like they know everything and they are gods. We do not need anymore big heads.

Re uploaded video... ok... my similar comment... i hate after market boards... OEM are better.... careful with the eyeballs... and that sounds like it.

Oh mama!! Steve L films all the time while working on those disgusting oil burners.