Troubleshooting all HVAC CIRCUIT BOARDS! Methodology and Procedures Used in the Field!

[@zunar_j5_933]

Just got the Refrigerant Charging and Service Procedures book in, love it!

[@acservicetechchannel]

That is so awesome, thanks!

[@quinnmath4722]

With your help over the years I am now the lead tech out of 30 guys.

[@sucdeeznuts1907]

Maybe now you can try to be the boss and not make someone else so much lhh

[@Viper81766]

Congratulations for applying yourself my friend 💯

[@JayLaJaLiyah]

I'm on my way bro 100k

[@JayLaJaLiyah]

I study his channel religiously ❤😅

[@deanmartin1966]

Your KZbin channel should be a prerequisite for new technicians or kids in school. If you’re new and you’re not subscribed to Craig’s channel then you’re missing out. There’s a wealth of free information that you can’t get anywhere else

[@russian3736]

and get his ac service book

[@deanmartin1966]

@@russian3736 I have one. It’s a great refresher

[@acservicetechchannel]

Thank you so much!!!

[@deanmartin1966]

@@acservicetechchannel Thanks for sharing your knowledge

[@nickdavis6284]

I’m 32 yes old 3 years in. I’m a subscriber and I love his videos. Very very helpful.

[@AN-kg4ei]

10yrs ago I had a bad relay and burned trace on my furnace control board. I ordered a new one but took a chance replacing the micro relay (very cheap for exact replacement), a blown resistor, fuse and trace. 10yrs later I still have the new control board in an unsealed box. One way that helps if you're very careful, is to lightly touch the relay during startup/call for heat routine. It may help narrow things down fast before even needing to break out test equipment. Pulling board from mains power under using 9-12VDC to test relay coils helps too. Great video! Thanks.

[@dexenationgracey1979]

One way I've learned to diagnose a board on heat pumps is to bypass the board and see if the fan kicks on.

[@sij2218]

I’m a new technician. Your channel is really helpful thank you so much

[@acservicetechchannel]

That is so awesome to know it is a help to you as you are growing in our trade!!!

[@rumulussmaraj8044]

From trinidad and tobago 🇹🇹....love the lectures, really really great

[@hephaestus369]

As an electrician, THANK YOU. easy troubleshooting guide, saved me from calling the HVAC guy just find out my thermostat crapped out.

[@MexBytes]

No 1 instructor in youtube for HVAC. I’m buying your book. 👍🏻

[@DellaroyEngineering]

The best hvac troubleshooting videos out there!!!

[@georgechen5282]

You should write a book about how to troubleshooting the hvac control board. Hvac techs will thank your helping.

[@edilsonserafim4784]

Craig you are really good thank you for being you I have grown so much and getting better with my techniques watching your videos.

[@hiepma6865]

Thanks!

[@acservicetechchannel]

Thank you so much!!!

[@jw5297]

Love your content. Watch videos when I can. Been at this for over 20 years, some of your methods are easier to show to helpers than try and help them understand how I go about doing things

[@mr.spliffaddikts9548]

I just want too tell u thank u for u videos n ur Knowledge u sharing on ur channel highly appreciated keep em coming

[@uf4661]

I hope novice techs learn a lot from your video! (My thermostat inside the house is not picking up the accurate outside temperature, when a tech from a company came and completely ruined the readings and it didn't show any reading. I was told by a different company that the circuit board on the unit outside was not working and not sending the signal inside. Then another tech told me it is the sensor itself which was not working so they changed it for $400+ I am now still seeing a wrong temp reading. The Carrier infinity I think was installed in 2013. Now my house doesn't cool no matter what temperature I set it to and it shows a constant 76 degrees inside. The person who installed the outside senor said give the sensor a few weeks! What is not working and who to trust.)

[@nellielee2915]

Thanks for your helpful teaching 🙏

[@Chris-vx5kp]

2:33 That's the exact control board in my POS air conditioner. Just looking at my my blood pressure rise.

[@phs84]

Hi, Long time viewer just a shout out from Aust. I am in the Hvac industry over here and find a lot of your content very informative and helpful. Keep up the good work

[@Jose-ot6xx]

Ran into this issue this year where I used my ECM tester to test the module of the blower because it wasn’t running and it ran when I used my tester. So I replaced the control board and surprisingly still had the same issue. Replaced the entire motor and module and then it started to work. Most of the time it will be the board if it turns on with the ECM tester but now I know that the module can still be bad even if your ECM tester turns it on. It was on a Lennox communicating air handler. Tech support also said this happens but very rarely and sometimes you have to replace the board and module at the same time for it work.

[@brianlittle717]

Great job explaining how they work. I always try to think if there’s a reason for a particular behavior and I always test the other components to rule them out and to make sure there aren’t other problems. Example: my last one was blinking the code for the pressure switch. Well the draft motor wasn’t on. I energized the draft motor and the pressure switch closed. After a minute, the gas valve came on. No igniter. So I energized the igniter to make sure it works. I made sure all the wires and connectors are good. I know that my safeties are good because the gas valve would never energize if they were open. I also know there is never a situation we would want gas but no igniter. This particular board has a 4 wire plug that combines hots and neutrals for both the inducer and the draft motor. Now I’m sure it’s a bad board and that it is my only problem. The problem is in the circuit for the 4 wire connector. I’ve also tested the connector and the harness by sticking meter probes into the back side of the connector so that a jumper can clamp onto the meter probe when I tested the igniter and draft motor. So my basic procedure is to test everything and rule them out. If there’s another problem, bypass or trick it, and see if it goes to the next step in the sequence.

[@trisoil]

谢谢！

[@davidb2438]

Craig, i have your books, big fan, however, your books are heavy on refrigeration aspect, and not the various troubleshooting of electrical issues. I think if you wrote a book on this, it would be a big winner. The only issue I see is that the electronics are in a higher stage of change, so updates would be more frequent.

[@mehdibourha180]

Thanks for the explanation you're the best 👌

[@davidnoren8260]

Great information and explanation. New to your channel. I will be watching.

[@artbeach1982]

Awesome channel.i was starting a wiring book myself .

[@randyshope4744]

Hello, I was wondering if you could do some videos on evolution inverter board, communicating, PCM boards,EXV’s how to check resistance new Bryant heat pump 284ANV series.

[@jonathangriesy4652]

GREAT video!!! As always. Thank you for sharing your knowledge!

[@jfoley1968jf]

Great video!!

[@turdsferbreakfast]

Good job. Cant wait to see how this turns out.

[@donaldpainter956]

True the most common problem I see on mini splits is the thermistor

[@pardeepkumar-go6px]

TNice tutorials is video is amazing! thanks for posting.

[@elliotramos8420]

You are a bless to us... Thanks.

[@acservicetechchannel]

So happy you are enjoying the videos!

[@brianb5779]

Been waiting for this video. Thank you

[@mechanicalmike7320]

Very clear, right to the point. Thank you!

[@randyshope4744]

Should try to use dielectric grease on all plugs on ECM motors to help them from heating up from high Currents.

[@donaldpainter956]

For the people that has trouble finding the problem buy an HVAC analyzer and it will run a diagnostic on the boards the motors the low voltage wiring it's real handy for variable speed motors

[@okhakhugaruba8551]

Pls how does this analyzer look like, the cost and where can I get one?

[@ZizoAwady]

Thanks a lot for your videos

[@acservicetechchannel]

I appreciate it!

[@taochen6833]

Hey, love your video. Its very thorough. I have a question. I have an IFC board that failed to run the blower motor, ignition sequence works. I was able to turn on the blower motor by bypassing the control board hence I figured the relay may have been bad so I replaced the board and it worked. I want to see if I can fix the board for fun. I was able to remove the two relays and performed continuity tests. They both passed for N.Open and N.Closed at 24V. Is there any other component on the board that may cause the power not to go to these relays? The fuse is fine. Thank you for your time.

[@ThePachucoMix]

Thank you for sharing your knowledge I really appreciate the videos that you are making even if English isn't my first language everything is well explained even I understand them 😁👍👍

[@ggarrickk4455]

You are a god send 🙏🏼

[@randyshope4744]

Maybe a video on dip switches also. Please

[@kousakasan7882]

I completely disassembled my main ac fan and motor thinking it was the motor. Tested it by connecting it to my second ac and it worked. I compared the two main boards using a voltage meter and found that the positive output for motor didn't have power. I ordered a new board thinking the relay was bad. Before the board came I decided to remove the old board. Turned it over and found a large black circle where the solder around the motor out had vaporized. I soldered it and it worked again. Now I have a spare board.... lol. I had stage 3 cancer and was going through chemo at the time. I blame chemo brain for not checking the board first...

[@NIN_THUG]

Search fembendazole for cancer

[@johnnyvaldez6006]

Can you do a video on how to size a home and duct designing?

[@keovongvilaykeo4799]

Count thanks you enough great content much appreciated dedicated for your hard working

[@acservicetechchannel]

I really appreciate it!!!

[@fisforfriendship6093]

if you know a certain voltage is supposed to be coming into or out of a certain circuit you can probably trouble shoot that way. start from the load side and work your way back to the source. use your knowlege to eliminate some circuits to check

[@ozziewelcome5612]

So so good

[@acservicetechchannel]

Thanks Ozzie!

[@davidlundy5007]

As these boards get bigger and fancier with all the sensors they fail more often and get a lot more expensive. That’s why they only offer an owner registered 10 year part warranty. After 10 years you are suppose to replace the entire system with a new ac/furnace. All by design.

[@donaldpainter956]

Bird nest or wasp nest in the vent pipe will give a pressure switch fault code also

[@AlejandroMorales-mf3zm]

I already bought you book Amazing

[@acservicetechchannel]

Thanks so much!!!

[@salvadorlopez688]

Gracias por El video exelente me ayudo mucho

[@UltraHydrophobiccoat]

How about 2 stage control boards with communicating thermostats?

[@donaldburton7150]

Helpful video!

[@donaldpainter956]

First rule anytime you work on a gas or oil furnace always check for carbon monoxide in the home even if it's a brand new unit

[@leojung3508]

Hi Craig I have a question about my HVAC. My Ac works for about a hour whenever I take out circuit board and put it back. I constantly have to do that process to stay cool this summer. I might think you might know the solution.

[@renecuevas4128]

You don't have to take it out...next time do not take it out. Just leave off for one hour n if there s no difference it means I m rite and u are just resetting the ac. About ac going off ALWAYS give specifics of Ac u got Could be a bad run cap or motor itself

[@thecurious6721]

Hi Craig, thank you for your videos 👍 I have a question if you dont mind :) We are supposed to use exact run capacitors for the motors. But amrad turbo200 capacitors have two 5 uf terminals used one is for 5/4 uf (dmm showed 4.7uf) and the other for 5/6 uf (dmm showed 5.7uf). I spoke with them, they said there is no effect on the motor performance/reliability if I use 5/4uf for 4 uf capacitor, but it is almost 20% difference. Some old ac's use 35/3 or 35/4 capacitors, so I am curious how it is safe to use 35/5 instead of them :) I would appreciate if you could explain it. thank you. 🙏

[@renecuevas4128]

No big diference u can use either or sometimes doing this every day give u the confidence and knowledge of trying new things...al most as trial and error. U kno . I do thiS bout 30 yrs already, never fails

[@thecurious6721]

@@renecuevas4128 🙏

[@MrSaniaFlame]

Is there any video how to repair pcb? Or you just change it to new one?

[@crispinplariza1503]

What is the right resistance when testing the thermostant sensor/and ambient temperature.

[@moneycalling8457]

You should come to Boston for a conference I will be the first one buying the tickets

[@ramonvenegas8535]

Thx for you video

[@copkhan007]

Quick question. On a 90% furnace the hot surface ignitor lights up but the furnace does not fire up. I disconnected the connection to the gas valve, and I was reading 9.2 volts. Did this several times to be sure and reading remained the same. I am assuming I have a bad board since I should expect at least 24 volts. What do you suggest?

[@LRBennettInc]

This a very good basics tutorial I like the way you have explained the different boards. But there are multiple issues that go deeper and one that comes to mind is loosing the common connection in the board. Very rare but happens and difficult to read if you aren't open minded for that problem. Thanks for your videos.

[@onlyulee866]

I have a question if a piston oversize would that lower or higher temperature difference..

[@sebausa1]

Awesome Thank you.

[@acservicetechchannel]

Glad you liked it!

[@sergeonevdah5164]

Hi, I have 3 speed fan blower motor 120volt Can you please advise which one control board I can instal for using 24volt WiFi smart thermostat? I don’t have a heater, only cool Thank you!

[@OthmanAlikhan]

Thanks for the video =)

[@acservicetechchannel]

My pleasure!

[@Ray-wr2wr]

hi what's causing blower motor working non stop ? relay on the board ? i troubleshoot thermostat its good

[@حسين-ج9ط7ي]

Great job, thank you brother. You are so talented

[@Dillonmechanical]

Thank you!

[@matttzzz2]

9:30 D F T = Defrost Femperature Tensor

[@Dbrooks0341]

I'm in school. I will say I learn more from KZbin lol

[@deanmartin1966]

Can you jumper from R to C? Lol. Kidding

[@mehdibourha180]

The best HOT to GROUND

[@dougrodger8208]

I wish people would stop saying cooling or the Y terminal is your high speed fan. It really regional. High efficiency Furnaces can require a large air flow across them in areas with a higher heating load than cooling load. Causing you to have a furnace heat fan speed to be set on high and maybe the cooling speed to be on medium or medium high. We run into a lot where the heating and cooling fan speeds are the same.

[@zachosborne6577]

Sequence of operations baby. Know what it should do.

[@jameskoecher6036]

Unusual problem with furnace circuit board terminal C: I live in Alaska and have a furnace only system with a battery powered honeywell thermostat. Red and white wires from honeywell to furnace terminal board. No connection to furnace C terminal and system works fine. I am trying to go to smart thermostat which requires connecting furnace C terminal to the smart thermostat C terminal and of course the red power and furnace white terminal connections. As soon as system sees power in this set up, it blows the 3amp fuse. New thermostat wire and new thermostat independently verified as operating correctly. Furnace C terminal to furnace ground has continuity which it should but there is continuity from the furnace R power terminal to its C terminal which indicates a direct short. Since the C terminal was never in use in honeywell setup, the issue never was discoved. Now I am blowing 3amp fuse using C terminal of furnace. Is my circuit board internally shorted? Can I get my thermostat C furnace connection by going to the negative leg of the 24 V transformer? The circuit board for my furnace is very expensive, $1K. Your guidance will be greatly appreciated.

[@yollydiazmillan5309]

hell were we can buy a replace board?

[@bruceboma357]

For every input, there should be an expected output.

[@eugeniorivera5522]

Any videos on trane Hyperion units

[@silasketgaskets8709]

In USA is pcb repaired or replaced?

[@nickgallegos430]

**HELP**. Does anyone have think control board could be the problem with my ac compressor not turning on. It sometimes does and works for days then will randomly stop coming on but fan outside comes on just not compressor. Capacitor seems to be fine. Switched it last year and still does same thing. Just have issues with compressor not coming on sometimes…Unit is for house built 2017 so not too old

[@rickross7796]

The tech mate pro works good in diagnosing ecm's

[@oso1165]

Good rule of thumb: If it's doing weird shit, it's the board 😂😂 jk jk

[@Alienspecies635]

If they have a nest it could be that too 😂

[@oscarcontreras4315]

👏👏👏

[@acservicetechchannel]

Thanks Oscar!

[@stephwaylonwells3218]

👍

[@INKDnARMD]

Just jump board out after you confirm your transformer is good.

[@arthouston7361]

The advanced ECM motors and inverter drive systems all claim "efficiency." That efficiency comes at a fairly high cost, and it is unlikely that a consumer can EVER recover the additional cost of such a system by that alleged "efficiency." If power is very expensive, you might come close, but you will never achieve enough operating cost savings to justify the added costs from an economic standpoint during the normal projected service life of the equipment. Then, all it takes is ONE repair...such as a $1500 control board or a $1,000 ECM motor to put you in the hole very deeply. All of these high tech systems are the result of the DOE requiring higher efficiency numbers, which makes them look good to the so-called "environmental" left, and the consumer of course is the one entity that pays for all of this misguided pursuit of better numbers. This dose of truth comes to you free from a lifetime of mechanical knowledge. You're welcome.

[@brandondelcox8065]

This comment deserves more attention.

[@matthewstewart9732]

Install them correctly and your chances of failure are pretty slim. Proper install includes surge protection and ensuring static pressure is correct. In my experience lots of people complain about new systems but don’t take the time to understand how to properly install and commission them.

[@arthouston7361]

@@matthewstewart9732 Surge is an upgrade that many turn down. No one can ever recover the addition cost of an ECM by energy savings.

[@matthewstewart9732]

@@arthouston7361 surge protection isn’t an upgrade it’s a necessity. Build them into the cost of the equipment. Installing inverter or ECM systems without surge protection is an improper installation practice.

[@arthouston7361]

@@matthewstewart9732 ...which customers will not pay for. The quote that is lower wins. ECO101.

[@smilleeguy1]

I dont understand why my comment or question was deleted. I have a possible stupid question. i'm not an amateur when it comes to using the meter, i did more refrigeration than air conditioning but i know my way around. so here's a question sir or anyone that care to jump in. i'm working on a honeywell ST9120C 4040 fan timer control board, much like one of the ones that you have in this video. it burnt a transformer so i took it out and wanted to bench test it, in fact, i have 2 used boards that i know was working and have very similar pins and also similar path from back of board. so my question is. if i were to just simply bench test the board by applying 120 volts at the right pins (upper right and neutral) and then connect a 24-28 volt 40va transformer and the right pins, and all voltage has been confirmed at both high and low voltage pins, aren't i suppose to get 24-28 volts between R and C at the thermostat terminal? or was i suppose to connect something to the board like the blower motor or the inducer motor. please help. thank you

[@mikeadler434]

👍👍

[@hishamchohan494]

Well, there should be a testing device,..... custom made..

[@mikev.1034]

👍👍

[@donio71]

When are you going to write another good book buddy?

[@acservicetechchannel]

Hoping to have our minisplit book out in a couple months! Be on the lookout!

[@kevinpearce3281]

I’m list

[@kevinpearce3281]

Lost.

[@aboriginal267]

Stop this video or the decepticons will find the all spark !! 😂

[@nebraskaman8247]

In my opinion that’s the biggest fail with newer technicians. Never turn the power off until you have fully diagnosed as much as you can with the power on. Otherwise your errors are likely gone. Slow down, and you will thank yourself later, as your life will be much easier.

[@JBK63]

Until HVAC manufactures include the type of diagnostics available on any modern vehicle it’s going to be a hopeless, time-consuming and expensive mess to try to troubleshoot a hodgepodge of electronics on these units. Manufacturers can’t even get their act together so that people aren’t having to replace capacitors right and left. These components are not designed for the temperature extremes found in outside enclosures. This controls circuitry should be mounted inside after all it is only driving a compressor a fan and a relay. A simple relay module in the outside unit is easy to replace and diagnose. The complex electronics should be inside. All of it is really overkill trying to reach efficiencies that are beyond the basic physics of the refrigerant and technology.

[@MaksimIzer]

Not a single use of a multimeter in this video, just a bunch of "could be, maybe this maybe that" This guy might be a plumber

[@edilsonserafim4784]

Craig you are really good thank you for being you I have grown so much and getting better with my techniques watching your videos.

[@alfredcasasola]

👍