Thermostat Wiring Explained in 90 Seconds!

In this 90 second video I show you how the connections that run between your thermostat and your furnace control board controls each of your home's heating and cooling components.

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[sarahcitau]

That was very well done! I usually glaze-over when people start explaining this stuff, but you made it clear and easy to listen to. I learned something!

[WeatherNut]

Best 90 second video I seen. Love the diagram.

[StevesBeyondRepair]

And again, informative and simple to understand! Thanks Ben

[Mike_]

Someone who is skilled and knowledgeable doesn't need to draw out all the details as proved here and produce a long boring video - very good clear simple explanation what a winner!

[xenochaosxc]

What are your thoughts on A/C covers for winter time in the rust belt?

[richardkumpf]

Ben, Nice video. This describes a basic thermostate which controls Furnace, A/C-Air Conditioner, and Circulation Fan if so equipped. It would be good to add the following info to include some missing items:
1. The Transformer mentioned converts 120VAC to 24VAC - AC is Alternating Currrent (sine wave power). Don't confuse with A/C (Air Conditioner)
This system typically controls 1-zone for either Heat Only, A/C Only, or both. RED & WHITE have alternating voltage/current.
2.Many 'smart thermostats' use the 4 wires differently:
The RED and WHT wires receive 12VDC (Direct Currrent - No Sine Wave) FROM the control board. RED=Positive, WHT=Negative
This voltage is used by the 'smart thermostat' to run the smart thermostat's firmware and display which supports multiple-zone temps and other
smart functions.
The other 2 wires are labeled 'I+' and 'I-' OR A and B. These 2 wires support digital (packet) communications (RS-485) between the smart
thermostat and the multi-zone control board, and possibly also to a wireless WiFi interface board which provides connections to the internet for
remote-control apps.
3. Hoping that this adds to further understanding for more advanced systems. -RadioRich in NH

[mrgauger]

Great video! I have been searching to see if you had one on doing a residential load calculation. I have not found it if you have. Could you do a quick rundown on how that is performed?

[pnky]

This video is so informative. I had no idea the furnace fan would be running when the thermostat calls for AC.

I have a nest thermostat and my ac is only intermittently working (mostly not working). After watching your video, I’m thinking the furnace fan is on because I feel air coming out of the ducts but I can see that the ac unit (which is outside) is not running. There is power to the thermostat but the ac unit is not powering on. Any suggestions about where the issue may be?

[JCWise-sfww]

Ben, I have noticed you wear your wrist watch on your right hand. Is your dominant hand the left one?

[JulioGarcia-dunv]

Wouldn't you need R to both W to turn on the furnace and G to turn on the fan to blow the heat like in cooling?

[tedlahm]

Does R to the W for HEAT also connect to the fan lead (green) the way it does for call for AC?

[jorgeortiz]

I have an old TOTALINE thermostat Mod # P374-100 that needs to be replace. This stat has an advance setting that lets me program it to turn the fan ON every hour for 5-10 mins at a time. What other thermostat will do the same? Please advise!!

[dmerks]

ben I have an air handler for my AC and a hydronic boiler with baseboard for heating basically two separate systems using a common nest E thermostat red green yellow from air handler and red & white from taco switching relay need help with proper wiring diagram thanks so much for the help

[aaronnunez]

I have a 4 / 5 ton system how I now wich thermostat I need for the unit ???

[michaelnoll]

How do you check that the C wire is working properly? My Nest that’s been working fine for 3 years suddenly isn’t getting a connection to the common wire (Error E79). Any thoughts from anyone? I’ve cut and reconnected the common wire at the Nest.

[AnAmericanFan]

While I am here, does anyone know of a thermostat that is split into the front or controls end of a thermostat, as in all human interfacing control and then a module controlled by the front end by RF to signal that various functions need to control that furnace or boiler itself? I have a thermostat that the remodeler quite stupidly mounted in a corner of the room to miss having to deal with a pocket door in the wall (instead of doing the installation PROPERLY). It is mostly hidden by a dining room hutch, in a “dead” room circulation zone and it’s very hard to get to. Thus the reason why I’d like to separate out the control end and actual thermostat and place it in a more appropriate spot. Rewiring to do this is not necessarily out of the question but would be extremely involved to do given the finished basement below.

[woolymittens]

Short and sweet. (that's what she said) 😂 👍

[RobertKohut]

A comment in 2 seconds... "Nice"...🙂

[commander_mamedov]

I have by now only one that i subscribed to someone's channel. And it is you Benjamin by now. I am not that one that like a kid subscriber to everyones channel. People even don't know who i am.