Our Book https://www.acservicetech.com/the-book This is for testing if a 24 volt thermostat is bad. These are the steps you should take in order to verify that it is the thermostat that is bad and not the wiring or control board. When you make sure that the power is on to the unit, the light (if there is one) is lit inside the HVAC system and nothing happens when you turn the thermostat on then this video is for you.
Support- https://www.patreon.com/acservicetech
Tool List- https://www.amazon.com/shop/acservicetech

Supervision is needed by a licensed HVAC Tech while doing this as Experience and Apprenticeship garners Wisdom and Safety.

All of the ACSERVICETECH Playlists- https://www.youtube.com/channel/UCOZR-1IqsAer9wzlvFgb4mA/playlists?view_as=public

If you want to support the ACSERVICETECH Channel and receive more HVAC content, check out www.Patreon.com/acservicetech

These Videos are all part of our Training Series on HVACR Service, Installation, Preventative Maintenance, General Knowledge, and Tips. Please comment and ask for videos that you would like to see in the future! We come out with new videos every few days from my job sites, service calls, and the training shop! I hope you enjoy and find them very beneficial! See you next time at ACSERVICETECH Channel!

Supervision is needed by a licensed HVAC Tech before doing this as Experience and Apprenticeship garners Wisdom and Safety.

ACSERVICETECH is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.
You can enter Amazon through this http://amzn.to/2aenwTq

The above link happens to be the Gauge Set that I use in my refrigerant videos but you can search from there.

Here is a link to the 24v Thermostat used in the video

Here is the Link for the newer UEI DL479 Multimeter with temp sensor- http://amzn.to/2jtsUbJ

Here is the Link for the newer UEI DL 469 Multimeter- http://amzn.to/2jw4ePJ

Here is a link to the UEI DL389 Multimeter used in this video- http://amzn.to/2av8s3q

Here is a link to Refrigerant hoses with valves used in the videos http://amzn.to/2aBumVI

Here is the Link for the Yellow Jacket Refrigerant Manifold Gauge Set used in the videos

Here is a link to the Digital Refrigerant Scale used in the video

Here is a link to the Imperial 535-C Kwik Charge Vaporizer for Charging Refrigerant- http://amzn.to/2oge0u9

Here is a link to the JB 6 CFM Vacuum Pump http://amzn.to/2nqbvo8

Here is a link to the JB Platinum 5 CFM Vacuum Pump with Valve

Here is a link to 1 gallon of JB Vacuum Pump Oil http://amzn.to/2mGrlXy

Here is a link to the Supco Vacuum Micron Gauge http://amzn.to/2bH98bO

Here is a link to the 1/4″ by 1/4″ female coupler from Supco – http://amzn.to/2kFrbU9

Here is a link to the Hilmor 4 port Aluminum Manifold Gauge Set-

Here is a link to the C&D core removal tool http://amzn.to/2bFpobQ

Here is a link to the Supco core removal tool http://amzn.to/2brEJco

Here is a link the Nitrogen Regulator http://amzn.to/2bXdR5f

Here is a link to the Nitrogen Flow Meter http://amzn.to/2brvoBg

Here is a link to the General Tools digital Psychrometer

Here is a link to the Amprobe Digital Psychrometer http://amzn.to/2d7cGkW

Here is a link to the Fieldpiece SDP2 Digital Psychrometer- http://amzn.to/2nniMVR

Here is the link for the Ratcheting Service Wrench http://amzn.to/2dGV4Nh

Here is a link to the Appion G5 Twin Recovery Pump http://amzn.to/2dGSEyr

Here is a link for RectorSeal Bubble Gas Leak Detector http://amzn.to/2ckWACn

Here is a link to the air acetylene torch setup, just make sure that this will fit your tank size connection. http://amzn.to/2aQalsb

Here is a link to the Malco Snap Lock Punch http://amzn.to/2cY53Ag

Here is a link to the Wiss 3 Pack Tin Snips http://amzn.to/2bHWhWO

Here is a link to the Wiss 5 Blade Crimper http://amzn.to/2bwTlsW

Here is a link to the Wiss Hand Seamers http://amzn.to/2dRk83v

Here is the link for the Hitachi Lithium Ion Drill and Flashlight kit http://amzn.to/2dzNgkL

Here is the link for the Irwin Wire Stripper/Cutter/Crimper http://amzn.to/2dGTj2V

Here is the link for the Hilmor 12″ folding tool http://amzn.to/2d9VTPR

Here is the link for the Malco 3″ Blade Combination Snips http://amzn.to/2dz7Ejc

Thank You,

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  1. My Service and Procedure Book-
    Tool List-
    For those that are looking for the tools used in the videos: (Linked Below)
    UEI DL479 Multimeter with temp sensor
    Magnet Jumpers-
    Alligator Jumpers-
    Fieldpiece ST4 Dual Temp Meter
    Fieldpiece Bead K Type Temp Sensor
    Fieldpiece Wet Bulb Temp Sensor
    Fieldpiece TC24 Temp Clamp
    Yellow Jacket Refrigerant Gauge Set
    Refrigerant hoses with valves
    Yellow Jacket Gauge set & hoses
    Yellow Jacket 4 Port Manifold w Hoses
    FieldpieceSMAN360 Digital Manifold Set
    FieldpieceSMAN460 Digital Manifold Set
    Compact Ball Valve for Refrigerant Hose
    QuickDisconnect 90 for refrigerant hose
    JB 6 CFM Vacuum Pump
    Appion Blue 3/8″ to 1/4″ Vacuum Hose
    Appion Red 3/8″ to 1/4″ Vacuum Hose
    Appion Valve Core Removal Tool
    Yellow Jacket 1/4″ by 1/4″ hose
    CPS Vacuum Micron Gauge
    Supco Vacuum Micron Gauge
    RectorSeal Bubble Gas Leak Detector
    UEI DL389 Multimeter
    Air Acetylene Torch setup
    15% Silver Brazing Rods
    Nitrogen Regulator
    Nitrogen Flow Meter

    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-

  2. I just solved my problem with my 1950″s Lennox Furnace with this video. Thank you for all the great videos!

  3. Awesome.. I have a new 2 story house with 2 separate air conditioners on ground floor outside but I accidentally touched the blue and red wire on the upstairs thermostat and now nothing works upstairs but the downstairs is fine. I guess i need to change that 3 amp fuse now, is that located in the attic on the heater board or the air conditioner outside? Thank u

  4. Excellent tutorial. I asked a guy years ago how he knew the tstat was failed, he said, ‘I jumped it’ and I assumed but didn’t know that meant (esp with multiple wires, and why). It makes sense if something is simply not turning on. If it starts/stops w/o hitting temp, I assume that is on furnace side?

  5. A service guy came and told me the first stage heat pump does not work because he could not feel the heat when touching the tube. Do you have a video to check which heat pump has problems in the two-stage electric AC+furnace system?

  6. My thermostat is set for 60 degrees at 3 am. The thermostat still runs at 68. Is the thermostat unrepairable? How long does a thermostat last? 10 years?

  7. What’s wrong when the thermostat works on fan only ? When put on auto the ac and the heat don’t work. It does nothing, no sounds or anything

  8. P L A Y Power check, Load check, All your switches, Your lines. Not the best acronym, but it’s honestly super effective for troubleshooting electrical issues. Start simple, and eliminate the simple stuff before moving onto more complex stuff. Obviously you use your common sense to skip steps, like spotting a burned connection or hearing a motor make nightmare sounds.

  9. Having problems with the air conditioning sometimes when it is on there is no cool air coming out..had a wellness ck up in june..guys said outside unit was fine just needed cleaning.. But once in awhile it seems the spark doesnt start the cool air..we turn it off for 10 mins..the on and it will start..could it be its not firing up correctly?

  10. I helped the fan by spinning it manually. It slowly turns on. Air is still humid. Not blowing cool. I turn the furnace off, but the fan still sounds like its on and it doesn’t spin.

    Would this be a thermostat problem?

  11. Thank you for saving me a costly service visit! Your suggestion of tapping the R and G wires helped me confirm a bad thermostat! Thank you for taking the time to produce easy to follow instructional videos with detailed explanations that don’t require hvac training to understand!

  12. Hi I have problem whith my termostat, it turn on no automatic just on and when I change the automatic it works. But when comes to the right temperature inside doesn’t turn off, and when turn off try to turn on again but sounds only a click on it and dosnt start. Can you help me please ?🙏

  13. My ac wasn’t blowing cold so I had a tech recharge the refrigerant. It helped but now, a week later, whenever I switch the thermostat from ON to Auto, the fan doesn’t blow. Any suggestions?

  14. What if my thermostat is off, but a/c continues to run? I have to pull the themostat from the wall to turn off the a/c.

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