Support The Channel- www.patreon.com/acservicetech Tool List- www.amazon.com/shop/acservicetech For those that are looking for the tools used in the videos: (Linked Below) UEI DL479 Multimeter with temp sensor amzn.to/2jtsUbJ Valve Core Removal Tool amzn.to/2uYr8WL Blue Vapor Yellow Jacket Gauge- amzn.to/2Ju7pan Red Liquid Yellow Jacket Gauge- amzn.to/2sSFmGH Quick Coupler for the Gauges- amzn.to/2sTk8Ze JB Test Gauge High Side- amzn.to/2ruQb0l JB Test Gauge Low Side- amzn.to/2qR0utM Manual Copper Tube Swage/Expander- amzn.to/2WRPa1M Uniweld Hydraulic Swaging Tool- amzn.to/2MlrI8m Uniweld Swage and Flare Kit- amzn.to/2T55jyn Ameriflame Oxy Acetylene Torch Setup- amzn.to/2SRm3JF #2 Tip for Oxy Acetylene Torch- amzn.to/2SPDaeD Cap-N-Hook Tip for Oxy Acetylene- amzn.to/2MbhpUk Air Acetylene Torch Setup- amzn.to/2aQalsb 15% Silver Brazing Rods- amzn.to/2gVLyLc Nitrogen Regulator- amzn.to/2bXdR5f Nitrogen Flow Meter- amzn.to/2brvoBg NitroVue Flow Reg- amzn.to/2MiulYv Ultrasonic Leak Detector- amzn.to/2Lw4Zpr UEI DL479 Multimeter with temp sensor amzn.to/2jtsUbJ Magnet Jumpers- amzn.to/2PyKPQZ Alligator Jumpers- amzn.to/2PxqJXn Fieldpiece ST4 Dual Temp Meter amzn.to/2wc1ME3 Fieldpiece Bead K Type Temp Sensor amzn.to/2DBwKfs Fieldpiece Wet Bulb Temp Sensor amzn.to/2RRI7Tw Fieldpiece TC24 Temp Clamp amzn.to/2qHLyjZ Yellow Jacket Refrigerant Gauge Set amzn.to/2aenwTq Refrigerant hoses with valves amzn.to/2aBumVI Yellow Jacket Gauge set & hoses amzn.to/2vLVkV9 Yellow Jacket 4 Port Manifold w Hoses amzn.to/2BkuGIq FieldpieceSMAN360 Digital Manifold Set amzn.to/2BdoaD4 FieldpieceSMAN460 Digital Manifold Set amzn.to/2nB4Fe6 Compact Ball Valve for Refrigerant Hose amzn.to/2KUisW8 QuickDisconnect 90 for refrigerant hose amzn.to/2MMtVcg JB 6 CFM Vacuum Pump amzn.to/2nqbvo8 Appion Blue 3/8" to 1/4" Vacuum Hose amzn.to/2uYlVyc Appion Red 3/8" to 1/4" Vacuum Hose amzn.to/2uYg6Ro Appion Valve Core Removal Tool amzn.to/2uYr8WL Yellow Jacket 1/4" by 1/4" hose amzn.to/2umtcod CPS Vacuum Micron Gauge amzn.to/2v1nM3O Supco Vacuum Micron Gauge amzn.to/2v1JRiA RectorSeal Bubble Gas Leak Detector amzn.to/2ckWACn UEI DL389 Multimeter amzn.to/2xAdaJf Other tool links can be found in the video description section. Shop through Amazon! Your Purchases through Amazon provide a means for channels such as mine to earn advertising fees from all purchases after clicking through. Prices are the same as normal- www.amazon.com/shop/acservicetech
One of the best channel for newer and older techs! Really appreciate you taking the time and effort to dismantle the parts and show how things work. Thank you!
Great video, I live in SWFL and we don't really deal with Heat too much but when we do I get lost because I forget everything. This video was extremely informative and broke it down real smoothly. Thanks!
hi im a business owner and most heaters are gass around here and ao electric heat is kind of my weakness but i fill so condident after watching this video and the electric heat video that you did thank you so much
(Time 4:22) Yep, I found the same burnt contacts on mine after working 11 years. The give away was the fan kept running with the strip heaters on from the contacts sticking intermittently. Great Vid and Thank you AC Service Tech and keep making those vids :)
Great explanation of a sequencer. Thanks for posting this quality video! I have had problems with furnace in the past and wish I would have seen this simple explanation at that time.
Question, my heat is not cutting off all the time ( even turning it off at the themostat it stays on ) I have to cut the heat off at the breaker for it to completely shut off. This problem is intermittent but it’s becoming more common. Could the heat sequencer be going bad,getting stuck? I’ve already replaced the themostat and the wires to the themostat seems to look good ( and none are touching- so I don’t think I have a short )
Yes, this I didn't understand, because most working with gas furnaces and heat pump. If you can make a couple of the videos about the sequence of operation electric heater and troubleshooting those, that would be great)))) thank you!
Hey Tapch, did you see this video on the electric strip heater voltage path? I started linking related videos in the description sections, thanks!- ua-cam.com/video/7_-x6u9uzhU/v-deo.html
I’m looking for almost the same part my only difference is the H20-45 on yours is a H20-40 on mine. What did you do to get a new part I can’t find one that’s the exact same anywhere
Can this cause an intermittent problem with the HVAC blower starting but sometimes not? I changed my motor capacitor, HVAC runs fine but sometime the fan blower does not start.
Thank you for all the help you’ve provided me along my way! Question though, isn’t it risky to test ohms like that on sequencers? Since you’re getting 240v after the bottom thermodisc?
I found an interesting problem with digital thermostats I never ran across before. When they house is 32 degrees, the "AAA" batteries shut down in about 12-15 minutes with a low battery display, and no more use out of thermostat signals. So you need to work REAL fast or lose the control signals.
Since the sequencer's bi-metal disc will flex due to heat, yes but once a little heat is generated, it is insulated by the plastic surrounding the disc so the heat will build fairly quickly. I don't think you will notice much of a difference in timing unless the seconds were counted critically, thanks and good observation!
Dumb question do you take heater wires off sequencer and turn breaker and thermostat on and then check continuity or can you leave breaker off and just turn on thermostat?
Really good explanation. I am having difficulty trying to figure out exactly how the thermal disc can drop the rods for the contactors at different times. Can you give a more detailed explanation for this?
Ok still little confused. If the heater snaps or moves just one time, how is there a difference in timing of the switches? Should both rods move at the same movement time as well?
Got a furnace with no control/circuit board that blew a transformer (no fuse) replaced transformer and added fuse and blows the fuse instantly when i turn the power on! Any thoughts?
I guess it saves wire. But after a good night sleep and reading the wiring diagram my head scratching is ended. The upper coil is wired in series, and taps off to blower motor. Couldn't figure out why it isn't always on. The blower just makes a big loop back to L1, so the entire circuit is just a big bus bar looking for a way out that the contractor supplies to L2, and the blower gets power backwards if relay doesn't kick on. Since AC doesn't care which way it works, all good.
so if im getting 21 volts at the wires going to the intermittent pilot module that are supposed to send power to the gas valve... that sequencer is the culprit ??!! I am getting correct voltage every where but at that point.... so the sequencer or the wires leaving the sequencer to the intermittent pilot are the culprits
So I was practicing with my multimeter on a working electric furnace that has no problem works normally. I shut the breakers off, thermostat is off. I tested the sequencer for continuity across the top prongs which I thought should be open, yet I got a continuity beep. I did not take any wires off the sequencer. Should I take the wires off to test? Do I have to take all the wires off? Thanks for video
The voltage would all depend on the application. In an air handler where the sequencer is switching a heating element, you're typically going to read 120v across 4 & 5 when the switch is open (as long as there are no other devices that are open in the circuit). Then you would read 0v across 4 & 5 when the switch is closed (heat is operating).
hi when these sequencers are failing, do you get chatter/machine gun sound? i'm up north, first freezing cold day today since the winter, -13c. heat pump is off as too cold, aux heat strips took over in the air handler. It is a Trane 4tee3f37b1000aa, system about 12 years old. Noticed when the aux heat starts, there's a machine gun rapid fire/chatter sound at the air handler, right about where the red 20KW line comes in. i'm not really familiar with relays but could it be relays that turn the strips on and off?? (sounds like a machine gun, fairly loud if i put my ear on the panel). Once the heat gets going and the fan is up to speed, it seems to stop, and then starts again a bit when the heat cycle shuts off. I'm still getting aux heat but not sure if the 4 strips are all working 100%. if i lost a strip or 2 out of 4 would the others continue to work or would they all stop?, Is there a fire hazard if either a strip is burnt or relay coils chattering furiously. Or could this noise be something else like arcing at the strips? the system cycles on and off a lot when it's too cold for the heat pump, nothing new but i guess that's normal, since the air is hotter, it gets back to temp fast compared to heat pump. If its a relay, how long can it function like this? is failure imminent? i am diy, have diagnosed and fixed blower motor, module before and other things like outdoor cap. Does this sound like a relay problem? thx I can easily open the from panel, just not sure what to look for.
Short cycling can be caused by many different problems. You could turn the power off and then disconnect the heat strips and blower and then turn the power back on to test the low voltage circuit for problems, thanks!
Normally closed and normally open basically just means what state the switch is in when no power is applied. Most of the time it refers to relays, contactors, sequencers, momentary switches, and devices that have a default position.
Service they may go a little hard on you but if it is mainly an installation position, they will likely be more interested in your safety, lockout tagout, situational awareness, communication with others, and being there before time- not on time. I have had them watching me on camera before my interview in the waiting room so from the time you get out of your car until you get back in your car, make sure you are in tip top shape. Good luck and let me know how you make out, thanks!
@@acservicetechchannel standard safty inspection for a new water heater with the unitrol valve requires turning up the thermostat nob until the dic clicks verifying its operation. I enjoy your videos.
Support The Channel- www.patreon.com/acservicetech
Tool List- www.amazon.com/shop/acservicetech
For those that are looking for the tools used in the videos: (Linked Below)
UEI DL479 Multimeter with temp sensor amzn.to/2jtsUbJ
Valve Core Removal Tool amzn.to/2uYr8WL
Blue Vapor Yellow Jacket Gauge- amzn.to/2Ju7pan
Red Liquid Yellow Jacket Gauge- amzn.to/2sSFmGH
Quick Coupler for the Gauges- amzn.to/2sTk8Ze
JB Test Gauge High Side- amzn.to/2ruQb0l
JB Test Gauge Low Side- amzn.to/2qR0utM
Manual Copper Tube Swage/Expander- amzn.to/2WRPa1M
Uniweld Hydraulic Swaging Tool- amzn.to/2MlrI8m
Uniweld Swage and Flare Kit- amzn.to/2T55jyn
Ameriflame Oxy Acetylene Torch Setup- amzn.to/2SRm3JF
#2 Tip for Oxy Acetylene Torch- amzn.to/2SPDaeD
Cap-N-Hook Tip for Oxy Acetylene- amzn.to/2MbhpUk
Air Acetylene Torch Setup- amzn.to/2aQalsb
15% Silver Brazing Rods- amzn.to/2gVLyLc
Nitrogen Regulator- amzn.to/2bXdR5f
Nitrogen Flow Meter- amzn.to/2brvoBg
NitroVue Flow Reg- amzn.to/2MiulYv
Ultrasonic Leak Detector- amzn.to/2Lw4Zpr
UEI DL479 Multimeter with temp sensor amzn.to/2jtsUbJ
Magnet Jumpers- amzn.to/2PyKPQZ
Alligator Jumpers- amzn.to/2PxqJXn
Fieldpiece ST4 Dual Temp Meter amzn.to/2wc1ME3
Fieldpiece Bead K Type Temp Sensor amzn.to/2DBwKfs
Fieldpiece Wet Bulb Temp Sensor amzn.to/2RRI7Tw
Fieldpiece TC24 Temp Clamp amzn.to/2qHLyjZ
Yellow Jacket Refrigerant Gauge Set amzn.to/2aenwTq
Refrigerant hoses with valves amzn.to/2aBumVI
Yellow Jacket Gauge set & hoses amzn.to/2vLVkV9
Yellow Jacket 4 Port Manifold w Hoses amzn.to/2BkuGIq
FieldpieceSMAN360 Digital Manifold Set amzn.to/2BdoaD4
FieldpieceSMAN460 Digital Manifold Set amzn.to/2nB4Fe6
Compact Ball Valve for Refrigerant Hose amzn.to/2KUisW8
QuickDisconnect 90 for refrigerant hose amzn.to/2MMtVcg
JB 6 CFM Vacuum Pump amzn.to/2nqbvo8
Appion Blue 3/8" to 1/4" Vacuum Hose amzn.to/2uYlVyc
Appion Red 3/8" to 1/4" Vacuum Hose amzn.to/2uYg6Ro
Appion Valve Core Removal Tool amzn.to/2uYr8WL
Yellow Jacket 1/4" by 1/4" hose amzn.to/2umtcod
CPS Vacuum Micron Gauge amzn.to/2v1nM3O
Supco Vacuum Micron Gauge amzn.to/2v1JRiA
RectorSeal Bubble Gas Leak Detector amzn.to/2ckWACn
UEI DL389 Multimeter amzn.to/2xAdaJf
Other tool links can be found in the video description section.
Shop through Amazon! Your Purchases through Amazon provide a means for channels such as mine to earn advertising fees from all purchases after clicking through. Prices are the same as normal- www.amazon.com/shop/acservicetech
I'm on my way to the Skills USA competition as I'm watching this. You're still my favorite teacher.
Wow Chris, I am so happy you are there! Please let me know how you make out! I am happy to have taught you for those two years!
He’s the best teacher I’ve ever had and I never met the man. Thank you Craig you are valued very much in our community
One of the best channel for newer and older techs! Really appreciate you taking the time and effort to dismantle the parts and show how things work. Thank you!
Thanks a lot Tak Leung!
Thanks for your teaching, patience and your knowlege!!!!!
Great video, I live in SWFL and we don't really deal with Heat too much but when we do I get lost because I forget everything. This video was extremely informative and broke it down real smoothly. Thanks!
As always I like your videos and watching over and over getting more good information every time
This man is the best at explaining things..
Outstanding training vid. Doing a surgical autopsy on the components to see their innards is most enlightening.
hi im a business owner and most heaters are gass around here and ao electric heat is kind of my weakness but i fill so condident after watching this video and the electric heat video that you did thank you so much
(Time 4:22) Yep, I found the same burnt contacts on mine after working 11 years.
The give away was the fan kept running with the strip heaters on from the contacts sticking intermittently.
Great Vid and Thank you AC Service Tech and keep making those vids :)
I hope that your second line would be true. I just got my Sequencer after two months, and I will put it in work tomorrow.
Great explanation of a sequencer. Thanks for posting this quality video! I have had problems with furnace in the past and wish I would have seen this simple explanation at that time.
great explanation of how the sequencer works. Your explanations are excellent and easy to understand!!!
Such an excellent video among other extremely useful videos, AC Service Tech 👍
Mr. Craig M.. is like the yoda of HVAC!!! full of knowledge.
Hes like a hvac mad scientist. He's awesome!!!
your videos has helped me so much
Awesome video! Always wondered how these worked!
Thank you for doing this awesome video! Very well presented and explained. I appreciate this.
You're very welcome!
This guy is a genius
I really enjoy your videos. Please dont stop. EVER! lol
Thanks a lot Kevin!
Great video! Can you do a video on belts and pulleys?
Aaron, thank you for letting me know what you would like to see!
Best explanation so far thank you
Glad you enjoyed it!
A great refresher for me. Thanks so much. How about a video on troubleshooting a gas ignition module? Honeywell and Whiterogers.
Thanks DM, have you looked up "acservicetech ignition playlist" I have a bunch of videos out on that subject, thanks
Excellent video.
Thank you very much!
Question, my heat is not cutting off all the time ( even turning it off at the themostat it stays on ) I have to cut the heat off at the breaker for it to completely shut off. This problem is intermittent but it’s becoming more common. Could the heat sequencer be going bad,getting stuck? I’ve already replaced the themostat and the wires to the themostat seems to look good ( and none are touching- so I don’t think I have a short )
Clear and concise explanation
Thanks Atch_N _Sons!
Yes, this I didn't understand, because most working with gas furnaces and heat pump. If you can make a couple of the videos about the sequence of operation electric heater and troubleshooting those, that would be great)))) thank you!
Hey Tapch, did you see this video on the electric strip heater voltage path? I started linking related videos in the description sections, thanks!- ua-cam.com/video/7_-x6u9uzhU/v-deo.html
AC Service Tech LLC thanks )! I'll watch
Thank you for your video. I have very hard time to find a "new part" for my Sequencer: PN# 14SH22 H24V 305886 4/5 H1-15 C45-110, 1/3 H20-45 C1-30.
I’m looking for almost the same part my only difference is the H20-45 on yours is a H20-40 on mine. What did you do to get a new part I can’t find one that’s the exact same anywhere
Great video! Thank you for all your instructional videos!
Thanks a lot G. Martinez!
Excellent demo. Thanks
Excellent tutorial. Thank you
Your vdo is really nice its easy to understand how to work these things
Thanks a lot Sajjan Lama!
I apprecite this. Thanks.
So what is the sequencers job function?
Great demonstration! Very didactic 👍
Many thanks!
great explanation!
Glad it was helpful!
Can this cause an intermittent problem with the HVAC blower starting but sometimes not? I changed my motor capacitor, HVAC runs fine but sometime the fan blower does not start.
Great explanation Craig ... Much appreciated ...
Thanks a lot Eddy!
I'm a tech. Great job!
Should we be reading resistance to powered circuits? Safe because it's only 24v?
Thank you for all the help you’ve provided me along my way! Question though, isn’t it risky to test ohms like that on sequencers? Since you’re getting 240v after the bottom thermodisc?
Awesome video 📹 👏 👌 👍 🙌 😀
Very helpfull. Thank you
Excellent!
I love cutaways they explain all.
Thanks a lot!
Good information thanks
GREAT INFO! TY!
As the sequencer is heated is it dropping the rod or pushing the rod?
Great video. Thank you.
Glad to help Jose!
good stuff. Thank you sir.
So great thanks
Heat sequencers reading 118ohms on the coil would mean bad sequencer? i had a few new heat kits read high out of box.
great video
Thanks a lot R B!
Thank you once again.
Thanks OSee 96!
Very instructionnal Thank you for you time
Thanks a lot Francis!
I found an interesting problem with digital thermostats I never ran across before.
When they house is 32 degrees, the "AAA" batteries shut down in about 12-15 minutes with a low battery display, and no more use out of thermostat signals. So you need to work REAL fast or lose the control signals.
If a sequencer is cold will it take longer for the bimetal disc to heat up and close the contacts???
Since the sequencer's bi-metal disc will flex due to heat, yes but once a little heat is generated, it is insulated by the plastic surrounding the disc so the heat will build fairly quickly. I don't think you will notice much of a difference in timing unless the seconds were counted critically, thanks and good observation!
Why would there be a sequencer along with a fan limit switch? Wouldn't the limit make a sequencer redundant?
Dumb question do you take heater wires off sequencer and turn breaker and thermostat on and then check continuity or can you leave breaker off and just turn on thermostat?
Really good explanation.
I am having difficulty trying to figure out exactly how the thermal disc can drop the rods for the contactors at different times.
Can you give a more detailed explanation for this?
Instead of just a snapping action, think about a slowly bending disc with the two rods in slightly different locations on the disc, thanks!
Thank you
Glad to help Murtaza Ahmadi!
Ok still little confused. If the heater snaps or moves just one time, how is there a difference in timing of the switches? Should both rods move at the same movement time as well?
Amazing…thanks.
where does the motor fan wire go on which contact
Got a furnace with no control/circuit board that blew a transformer (no fuse) replaced transformer and added fuse and blows the fuse instantly when i turn the power on! Any thoughts?
I guess it saves wire. But after a good night sleep and reading the wiring diagram my head scratching is ended.
The upper coil is wired in series, and taps off to blower motor. Couldn't figure out why it isn't always on. The blower just makes a big loop back to L1, so the entire circuit is just a big bus bar looking for a way out that the contractor supplies to L2, and the blower gets power backwards if relay doesn't kick on. Since AC doesn't care which way it works, all good.
Gracias
Thanks Lucas!
so if im getting 21 volts at the wires going to the intermittent pilot module that are supposed to send power to the gas valve... that sequencer is the culprit ??!! I am getting correct voltage every where but at that point.... so the sequencer or the wires leaving the sequencer to the intermittent pilot are the culprits
So I was practicing with my multimeter on a working electric furnace that has no problem works normally. I shut the breakers off, thermostat is off. I tested the sequencer for continuity across the top prongs which I thought should be open, yet I got a continuity beep. I did not take any wires off the sequencer. Should I take the wires off to test? Do I have to take all the wires off? Thanks for video
Yes, you should take off all the wires on any devices before you do continuity test.
Do 240v hvac transformers supply 24v dc or ac current?
Almost always AC. Some air handlers do use 22v or 28v DC relays, but that is accomplished by a rectifier. The transformer is still 24v AC.
Hey can you do a video for transducer troubleshooting furnace
Hey AJ, I think you mean transformer troubleshooting. Just look up "acservicetech transformer" for a video on that, thanks
@@acservicetechchannel not transformer. I need some help with Modulating Furnace Transducer Troubleshooting
What would be the voltage between 4 and 5?
The voltage would all depend on the application. In an air handler where the sequencer is switching a heating element, you're typically going to read 120v across 4 & 5 when the switch is open (as long as there are no other devices that are open in the circuit). Then you would read 0v across 4 & 5 when the switch is closed (heat is operating).
what happens if the contacts get stuck closed?
hi when these sequencers are failing, do you get chatter/machine gun sound? i'm up north, first freezing cold day today since the winter, -13c. heat pump is off as too cold, aux heat strips took over in the air handler. It is a Trane 4tee3f37b1000aa, system about 12 years old. Noticed when the aux heat starts, there's a machine gun rapid fire/chatter sound at the air handler, right about where the red 20KW line comes in. i'm not really familiar with relays but could it be relays that turn the strips on and off?? (sounds like a machine gun, fairly loud if i put my ear on the panel). Once the heat gets going and the fan is up to speed, it seems to stop, and then starts again a bit when the heat cycle shuts off. I'm still getting aux heat but not sure if the 4 strips are all working 100%. if i lost a strip or 2 out of 4 would the others continue to work or would they all stop?, Is there a fire hazard if either a strip is burnt or relay coils chattering furiously. Or could this noise be something else like arcing at the strips? the system cycles on and off a lot when it's too cold for the heat pump, nothing new but i guess that's normal, since the air is hotter, it gets back to temp fast compared to heat pump. If its a relay, how long can it function like this? is failure imminent? i am diy, have diagnosed and fixed blower motor, module before and other things like outdoor cap.
Does this sound like a relay problem? thx I can easily open the from panel, just not sure what to look for.
Is the heat sequencer what causes short cycling?
Short cycling can be caused by many different problems. You could turn the power off and then disconnect the heat strips and blower and then turn the power back on to test the low voltage circuit for problems, thanks!
Normally closed and Normally open. I’m trying to grasp the concepts. Is it On/Off or Off/On. Thanks.
yes you will see NC and NO on electrical wiring diagrams or an open line on the circuit if it is NO, thanks
Normally closed and normally open basically just means what state the switch is in when no power is applied. Most of the time it refers to relays, contactors, sequencers, momentary switches, and devices that have a default position.
👍👍👍
hey i have a commercial hvac interview saturday... anyone give me any tips or hvac questions they may ask ?
Service they may go a little hard on you but if it is mainly an installation position, they will likely be more interested in your safety, lockout tagout, situational awareness, communication with others, and being there before time- not on time. I have had them watching me on camera before my interview in the waiting room so from the time you get out of your car until you get back in your car, make sure you are in tip top shape. Good luck and let me know how you make out, thanks!
AC Service Tech LLC Thanks. i’ll let you know
So. Cal. Gas calls it a clicks on disc.
Yes it is a bimetal disc that sits on the pan heater and Klixon and Sensata are the manufacturers
@@acservicetechchannel standard safty inspection for a new water heater with the unitrol valve requires turning up the thermostat nob until the dic clicks verifying its operation. I enjoy your videos.
What a flimsy design!
A great refresher for me. Thanks so much. How about a video on troubleshooting a gas ignition module? Honeywell and Whiterogers.
Thanks DM, have you looked up "acservicetech ignition playlist" I have a bunch of videos out on that subject, thanks