Excellent explanation, I dealt with this for the first time earlier today and afterwords my boss sent me this video for learning purposes. Pretty cool knowing how everything works now and being able to better understand the system as I progress in my career.
One more thing to know, multiple offenders do happen and it is also possible that the reversing valve is also stuck, if you jump it and it's still in heating mode the valve is stuck, his obviously works because it's defrosting. An important lesson I have learned the hard way is don't stop just because you found a problem because there can always be more problems or things that will become a problem, doing this helps prevent call backs. I just went on a refrigeration call running a part for a tech that is on vacation. The diagnosis was a restricted cap tube and he was right but the compressor sounds like it's full of rocks and the other tech absolutely should have quoted a compressor as well because that one's days are numbered. I would have changed it on that service but the closest supply house to that customer is nearly 2 hours away one way.
Good video. New subscriber. I recently had to troubleshoot the defrost board. The temp. Sensors ones-out five according to the ambient temp. Reversing valve was getting 24v but was not operating. I removed and cleaned the connectors to the reversing valve, and it then worked fine. Simple fix.
Dude you just saved me a few hundred bucks. My Lennox was totally frozen over and I wanted to understand what was wrong and get some heat before the tech came out. I tested the defrost sensor while it was in a block of ice and sure enough no continuity. I jumped the DF and pulled the fan and ran 14min( apparently that how long Lennox runs??) defrost cycle until most of the ice was melted. When the tech came out he did his checks and totally said my board was bad and wasn't sure about the sensor but that it would get replaced with the board ~$400. I said thank you and paid $90 for the service visit and ordered my own replacement sensor online for $40. I had a question though. If I ever had to manually defrost again can I leave it in defrost until thawed or just 14min intervals? Bc that was slow as heck only doing 14min at a time
I stay up late looking at the video s love love them I'm in school so you know I'm excited hvac was my last one to learn but awesome you are a great teacher
Just discovered you. As a newer tech, I really appreciate these service call videos and your explanations/approach. Thank you for taking the time to record and upload!
This video is good for an AC tech that wants a little more knowledge, But for the do it yourselfer trying to do it for the first time it needs a little more up-close shots of what you are talking about, and maybe a little more explanation. But non the less thank you very much for the video.
by coil sensor you mean the DFT, like the wires you disconnected go to the DFT. I'm assuming you just used different terminology. I know some boards label them both "DFT" and other boards have a "DFT" and "R-DFT" basically the same thing.
Question if you simply switch your unit from heat cycle to AC cycle wouldn't that in around about do the same testing which if it blew cold air it would eliminate the reversing valve and puts more attention toward the board and the sensor or does the board totally shut power access to the reversing valve is there an alternate power source that operates the reversing valve
Great videos! thanks so much for sharing your knowledge. I hope you could help with the following. I have a York heat pump that is not heating enough and it seems that the blades are not turning. I change the filters did the resenting, putting the thermostat all the way down and starting again and it did work. But it only heats for a little then it blows cold air, Please kindly advise. Thanks so much in advance!!
What if we have an barely new heat pump about a year old that’s icing up just like that and buy what I seen I suspect it’s something to do with not going into defrost as it runs fine heat output is fantastic until it gets cold and ice is up but I forced it into defrost and it went into defrost and my coil sensor is showing open during normal heating cycle on a fairly warm day where it’s not icing up could it still be something in the board or The coil sensor itself? It’s a RUUD HP
It sounds like the sensor. Rheem/Rudd has had tons of issues with there sensors the past couple years. I would almost guarantee that’s the problem. I actually have a video on that exact issue and show step by step on the repair. here’s the link: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-yOYM3apIZ2g.html. I also give the part number in the video and you may be able to order it online.
York heat pump reversing valve is continuously chattering. When I disconnect the wires connecting to the reverse valve the chattering stops and unit will work in the heat mode but it will start icing up. The voltage on the coil wires never shows zero volts. Should I replace the defrost control board or you may have some suggestions to properly debug the system.
I know this video is a year old but I hope you see this comment! Had a comfort maker iced up like that, tried to put it into test mode and it wouldn’t defrost, put jumper wires in the temp sensor pins and it went into defrost but for 2sec, so I changed the board and still did the same thing…….any suggestions?? Thank you!
Yes they are in certain sequences. You can check on the board and it should say what sequences are error codes and which sequences are normal operation
I don't now why the voice seems very low. When you start talking direct to us i heard you very well, but as you did the demonstration when you start talking about the fan, i couldn't hear anything.
I just subscribed. I have 43 Lennox heat pumps. Have you installed any low ambient fan kits on any? These kid’s run the a/c when it’s cool outside and they go into low pressure lock out. Thanks
On a Goodman, i just disconect the fan wire from the board after turning off the power, then i connect the fan wire to the contactor, turn on the power, if it goes into defrost that means the board is bad. Can this be done on a Lennox? Or i have to follow your instructions in this video? Thsnks.
