I watched several videos and this one walked me through like I was an idiot. I am an idiot when it comes to a/c. The step by step instructions were easy to understand and follow. My central air works again and I saved easily $400. Well done sir.

Just wanted to drop in and say ty so much for your videos. I'm financially hard up and hiring a professional just wasn't in the books. We either had to figure it out or learn to live without. Your information clearly and plainly helped me understand how to diagnose and solve. I feel like I owe you more than you've given me. My family is grateful for your educational videos. Ty and God bless!

Your tutorial was spot on for my LV short circuit. Nobody else covered this procedure like you did in detail. They say do this do that, but do not explain what is happening. Your are a very good HVAC teacher. Thank you!

You wild for pushing in that contacter with your bare finger! 😎😎😎

FYI, if it turns out you have 24 volts in the air handler, but not at the thermostat, check the overflow sensor (safety switch)to see if it's keeping the unit from turning on. Thank you so much for this video!

Great walkthrough with clear and detailed steps. I was replacing thermostats and blew the fuse. You saved me $$$ with this video. Good Karma coming your way my friend. Thank you!

One of the best videos for informational purposes. Describes the process and parts but doesn't go off on confusing rants. I'd use this as a training video for new techs because no matter what system is in place this process is going to be essentially the same whatever you're working on. Thanks!

You saved me hundreds of dollars! I relocated my nest thermostat and accidentally connected the wires without knowing the consequences. After watching your video, I fixed it with a $2 fuse!!! Thank you!

Just followed your steps exactly and this fixed my issues at 5am. Wife got up with the baby and noticed it was 76 degrees in the house and I had the issue fixed within an hour. Can’t tell you how thankful I am for your video.

Had a no a/c power showing on thermostat, checked all the initial things like circuit breakers, both disconnects on air handler and condenser. Checked the buss fuses. Started searching here for more in depth diagnosis. Found your video, followed the methodical step by step procedures. Turns out it was the fuse in the air handlers circuit board. Replaced and back up and running. Thank you for an easy to follow approach to figuring this out.

Sam, you're a great teacher. Your knowledge, delivery and patients were perfect. Thank you Sir.

Sam, your video was EXTREMELY helpful. Instead of a $180.00 thermostat I only came out of pocket a $5.00 pack of 3 Amp fuses. Thanks a bunch

It's also important to address how the fuse blew. I would check the 24v coil on the contactor at the condenser and read the resistance. These coils can start going bad and take 3 amp fuses out and cause frustrating call backs.

Great video; thorough and logical. The 3 amp fuse on the air handler circuit board was indeed the problem. I would have had to pay $200 for an emergency service visit, if not for this video. Instead, I spent $5 at Ace Hardware and -- problem solved! Thanks so much!!

I am installing a new thermostat and things I read online suggested a I blew a fuse, but didn't really help me with where to look. This is very helpful. Thank you!

Sam: THANK YOU! This explains a lot. I will check tomorrow morning whether I have the similar board and a fuse that I can replace. This afternoon, while trying to be a smartass I may have blew that power. My problem was a that the CAP was out. I did replace the cap first. The contactor relay was kicked but the FAN and the compressor was not running in while the bad cap was there. By the time I procured an appropriate CAP and replaced it, the thermostat (which I have a NEST), may have stopped calling for cool. While working outside, I looked around for other reasons why the compressor did not start. I found this little fixed thermostat-looking "Crankcase Heater Kit" that was terminated between L1 and T1. Thinking that it needed to be normally closed, after measuring it open using my Multi-meter, I cut that out and bypassed it by shorting the two leads that went to it. That must have done it! Killed the Low voltage power fuse due to the flow of unusual current through the circuit. After that, when I pressed the contactor in with a screw-driver, the fan and compressor ran fine (with the new CAP). But it will not run under the thermostatic control. Playing with my NEST Thermostat, found that it was complaining about Power and was showing an error code "e-23". Called Nest support, they were somewhat knowledgeable on the troubleshooting of their Nest product, but not enough to tell me what could be wrong with the Air-handler side control Unit that supplied the low voltage power. Your Video was quite helpful and makes sense, that the fuse may have blown in the control board. However, my model Carrier, may have a different control module. I will have to search for the fuse location if it is in a different location. I will let you know what I find tomorrow. Again thanks. Great Video and you earned a subscriber!

Awesome video, after following these simple steps cussing out the wife and kids asking me every 5 minutes " Does it work yet it's hot" and because of their encouragement and support I decided to purchase a new Hvac system, , , which I now enjoy with my new girlfriend and her kids.

Dude you are a stud! Thank you!! I know my stuff when it comes to electrical with 25 years experience. Today my detached garage AC stopped working. I checked the voltage at the thermostat. No voltage. I pushed the coil on the GP contactor. Worked! Next stop is the rafters to the control panel. Thanks for your help.

This helped me solve a problem where I was not getting 24v at my thermostat. Thanks for the video! You probably saved me $150!

Great video! I just started my HVAC career and I’ve been doing a lot of service no AC calls. These type of videos are definitely helping me out with trouble-shooting issues. Thanks brother👍🏻

Just wanted to say thank you. I now know how to properly diagnose with just a multimeter instead of trying to replace parts. It happened to be the fuse on the unit I was working on.

6:05 ! Replaced the capacitor, Start capacitor, Start relay, and contactor…still no power to fan. Found the #5 fuse in my unit in the attic BLOWN. Cheapest replacement part and that’s what got me back up and running 💨. Thanks Sam you the man !

Thank you very much for this video! It helped me diagnose my AC issue and got it back running and blowing cold air. My wife and kids think I'm some sort of superhero now...

Thank you for very detailed and thorough video. I had already working through the steps confirming no power at the thermostat but didn’t know where to go from there. I had the same fuse issue. It got my ac up and running and made the wife happy. Thank you!

Guess who changed thermostat with out cutting off the main board 😩 this guy. U saved me a few hundred. Thank God for space heaters. I’ll buy the fuse in the. A. M. Great video

THANK YOU SIR!! This was the exact issue I had...saved me a $125 Home Warranty fee for a tech to come out to the house

if you've got a popped fuse, it's because of a low voltage short. before replacing a fuse, you need to find where that short is. if not, you are going to have to replace that fuse once again.

Good video. I do commercial bar concession stand refrigeration at work but have never opened a typical residential split a/c system until recently. Went to change out a worn contactor and capacitor on a dirty but functional system. Cleaned the condenser coil, ready to restart the unit thinking I'm gonna cash in some hero points on this friends and family trade... plug the disconnect back in and....... nothing. Huh? Took a while to figure out that even though I pulled the outside unit disconnect that I had shorted out the low voltage while changing the contactor. Live & learn every day. Thanks for sharing.

You rock Sam. Loved the way you logically walked through the steps... it all made sense to me and I was able to pin down my issue also (mine was on the transformer)

Great video! Thanks. The wife is happy again!

This resolved my issue! Thank you very much for taking time to show us these steps!

I am so happy for the family in the video. They won't be suffering like my family did last night ! ! ! I am going to climb up in the attic with my newly gained knowledge and fix me an A/C unit ! ! ! PRAY FOR MY SAFE RETURN.

Just wanted you to know that your blog helped me find the only problem with my unit was the fuse on the control panel, thanks a million!

Legit just saved me! My ac went out mid day yesterday and then today bought a new thermostat and nothing! Then worked my way to the 3A 32V Fuad and BAM it was blown. Purchased a pack of 5 for $6 after taxes. THANK YOU

Thank you! You saved me from a wife with no AC in 95 degree heat in Florida. The very old thermostat had a burnout on the circuit board and nearly caught fire. I installed a modern thermostat and rethreaded the wires as they were the root cause of burnout out on the very old thermostat. I then had to replace the 5 amp fuse as it thankfully failed and protected the rest of the system. Now everything is working great and with the modern thermostat better than before.

Great easy to follow video. Had the exact same issue and was able to easily fix for under a dollar saving me hundreds. Thank you!

update : without doing anything the ac started. I do have the 24v back at the thermostat. While it is a good news, there is trouble as well. I was not able to "fix it", it just fixed itself, which we all know isn't exactly a fix. So I suspect control board contact issue. I already have the same problem with the gas heater, often works, sometimes not and I narrowed it to control board issue. I might have to buy both control boards. Anyway still the video helped me and was awesome so thank you !

Great video, solved my issue with no 24v, bad fuse. Without the video I don't think I would have found the fuse or even know there was a fuse.

This guy helped me fix my ac with that burnt fuse. Saved me $85 bucks hell yea

Wow this seems to be exactly what I'm facing right now. I have no power to my 24v wire at my thermostat. I need to test the other things you mentioned now. Also there is a bag of fuses on my unit upstairs from a technician when he was here last. Thanks!

Thank you for your instruction, my AC systems have same problem, my thermostat voltage measured 2.4 VAC. I followed your instruction and found the fuse in the blower unit which located on the attic. My AC back up and running after i replaced the fuse. Now the thermostat voltage measured 28.5 VAC.

Just wanted to echo what others have said previously. After I installed a new thermostat, it didn't power on. I found your video after asking Doctor Google for help. Thank you for the thorough and clear explanation. I traced the problem to the fuse in the air handler. Replaced the fuse and everything worked.

Thanks! I was trying to connect my 24V return so I could use a wireless thermostat. Must have blown that fuse. Not only is it fixed, but the wifi thermostat is working like a champ. Thanks!

Great video. I had the same issue. I installed a new Honeywell thermostat without looking at the directions. Long story short, I had two wires, O and B connected when I just should have had O. For whatever reason that shorted the control power on the heat setting only (not cooling) and blew the control power fuse. Today was one of those learning days. Thanks Sam!

$4.15 for two fuses at Home Depot, system now running, thank you so much for your putting up this video. Installing a new Nest thermostat I must have touched the wires, despite trying not to.

Thanks Sam. It was my low voltage circuit fuse. I saved a couple hundred changing it myself. You really helped me understand the system.

Thank you! This happened to me yesterday and your steps solved it exactly as you showed them. What a relief.

This video saved me!! Just crawled out the attic to write this. It definitely was the fuse. Wierd that my compressor wouldn't turn on but my motor in the attick would run automatically even without the thermostat attached. Stuck relay maybe? Regardless I now have cool air.😊

BRO! BRO! BROOOOO!!! You saved me and my family from turning into rotisserie chickens! Thank you so much! This was definitely my problem and you helped me fix it! 👍👍👍👍

Awesome explanation and diagnosis. Thanks for posting, you helped get my house chill!

After hours of watching videos and testing finally found your video and the blown fuse in the air handler. Thank you!!!!

def gonna have to check the air handlers now at the school I was at because I had no power all across the thermo wire. Good troubleshoot! thank you!

You're the man! Thank you! There's a heat wave coming, my kid is sick and you brought my AC back to life!

Great video, organized and to the point. My problem is solved. Nice to see a video that is intelligent and a great educational process of elimination through testing and moving on to next component to examine/test.

Thank you for confirming anything between 24-28 volts should suffice. I have been trying to figure that out if 28.2-28.5 volts is too much voltage for an Amazon smart thermostat!

This video helped me immensely. The heat was not turning on, and My GFI needed a reset.. Thank you so much Sam.

Your video got me up and running! I blew the fuse when I changed a thermostat ( rookie mistake ) thanks for bailing me out so I can sleep tonight in a cool house instead of a hotbox....thanks again

My man just raw dawging pushing in that contact…

I don’t usually leave comments but this one is well deserved. Thank you!

A good video, you addressed all the details, very useful for greenies, I thank you for them, I was one of them.

you my sir, I owe a drink!... saved me a nice bill that only took me 10 minutes to resolve! thanks

Your blog actually helped me solve my a/c of starting up problem much appreciated.

Great tutorial. I bought a house here in Vegas and there were wires coming from 1 Furnace to another. I checked because i upgraded to a smart thermostat and needed to connect the C wire. I suspect the transformer is busted because i checked the same purple fuse and it was ok, but the red board light was not blinking while pressing the black safety switch.

Thank you bro! I think I Found my problem using your steps. My transformer was not sending out 24v. Ordered the transformer and hopefully fix my hvac! I'll check back in in 2 days

Thanks a lot. I feel so dumb. After I installed my new thermostat after the old one died, the out door unit still didn't work. So I just replaced the capacitor even though I already replaced it 3 years ago. Still nothing. I bought a voltage meter and checked the contactor and it received 240v. When you showed the thermostat wiring I decided to check my wiring. Yup. The wrong wire was in the wrong port. I had the white wire in the White port. It supposed to be in the Yellow port. Fixed. I was worried I had to go up into my attic.

Well you just saved me at least $100. Had low voltage on my tstat (must have shorted when installing my nest), checked out the things in your video and swapped the 3 amp fuse. Works fine now. Thanks man!

Another great video to find and fix a/c not working. Thank you Sam.!!!

Great videos . Traced my contact not pulling in to exactly this " a blown fuse" .. saved me a fortune.Thanks!

Thank you. excellent demonstration. the video shows exactly what the troubleshooter needs to know. Thank you again!

I was pulling what little of hair i had left out!! BTW not good for a strugglin hair farmer 😆😉 AWESOME video describing step by step to chase and troubleshoot the REAL issue.....board fuse!! Thanks* So very much for this video!! 💖

Suuuper helpful! People helping people. Good humanity! This was exactly the problem. Thanks you!

Awesome information, very clear and concise. Thanks for sharing.

Very helpful. You are spot on with your repair methods. This is such help. Thanks

Hey Sam, following these steps helped resolve my issue as well. Thanks a bunch!

This was really helpful, thanks. Based on these steps, I was able to narrow down my issue.

Great video on resolving my issue. Thanks, my fuse was blown. You saved us $. You rock!

Thank you for taking the time to explain this.

What a legend. My fuse was definitely old and popped. Replaced it and it's back working fine. A can of coke to you, sir!

Excellent video you did a great job explaining. Headed to ace hardware to buy a fuse. Thanks again! PS you should have been a school teacher.

Many many thanks for all this step by step informative video with a really clear explanation...keep the great job

You rock...very well thought out and walked through step by step. Hopefully my similar issue gets resolved.

EXACTLY my issue. I had no idea. You, Sir are awesome. Thank you.

Thank you so much for your Time & Video. It is very helpful and easy for understanding . I love it. God always Blessing you and your Family.

Fantastic info!! I appreciate you good gentleman..God bless you

Great way to diagnose a system issue. Well done bro

Got my ac back on with your helpful video.Thank you

This was the issue with my system, and you made it very simple to understand and track down. Thanks a lot!

Good job explaining even someone with no experience could understand

I found out that the furnace was off from the power panel. I put it down by mistake last week. But, I know now how to check all voltages. Thank you.

Thanks sam I really learned a lot from watching your videos, you are a good teacher,keep up the good work 👍🏽

High quality video, hoping this is the issue when I climb on the roof tomorrow

I only wanted to install a nest thermostat now I have no power on my thermostat wire.. I probably blew the fuse.. since the wires sparked a few times… thanks for the video!

great explanation,thank you...I reiterate the same sentiments as hornet224 has commented .....

Perfect tutorial for a guy like me...thank you soooo much!!!

Thank you so much. Went to replace my thermostat and it wouldn’t turn on. Put the old one back and it still didn’t work. Checked the fuse and it was blown.

Thanks! Mine was an older unit and had a little breaker instead of a fuse, but this helped me find it.

Thank you so much. It help me a big deal to troubleshot the problem. Great video. Thank you.

Excellent, thorough, to the point.. Very nice job. Thank you.l

Man u r best. Plz teach us more about AC.

Thanks for posting this! It was a big help!