Good vid but one correction, you are in voltage mode, so you are not "getting current from it". Current is when you complete a loop and draw current through a load. Technically a meter is a load, but it is designed to draw as little as possible, so this is not a current but a voltage test. It is, however, good advice. You should see voltage only between Red and C wires but not between C and any other wires. In addition, you should see voltage between red and basically every other wire (W,G,Y). Note the meter is in AC voltage mode and should read around 24V.
Just an FYI if you remove a thermostat while the unit is running and replace the thermostat with the stat still calling for function, it may pop the fuse on the circuit board.
C (common) wire is a bit confusing, its referred to as if it's a hot wire that provides current, when in reality its a return wire that completes the circuit from the red hot wire... what is even more confusing is that smart thermostats need it and instructions also refer to it as if were a separate source of 24v
@@n.g.1577 figured it out after much confusion.. wished they just called plain and simple- a hot 24v source.. "C wire" is too misleading... My furnace didn't have a C wire connector, so I tried tapping into the existing 24v hot but the load was too much.. so I installed another 24v transformer to solely power the thermostat C connector.
my current wokring thermostat wiring has the blue wire on G, and I'm trying to install smart thermostat. Should I simply keep the same wiring or put the blue wire on C.
Sorry for the newbie question. What happens if I touch the red pen to "R" and the black pen to "C"? Will be the value 0 or -27? Because I don't have C-Wire, I purchased a 24v transformer Wall adapter from Amazon. Maybe because Chinese brand or a cheap brand, it doesn't have any mark which one is for C or R. I want to test with a multimeter before just guessing and plug to fry out my furnace. I like to know what kinds of results I get if I test in the opposite way. Thank you.
Because it's AC, it will still read +27 whether you put black to R and red to C or black to C and red to R. Polarity makes no difference in an AC circuit.
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Simple, short, to the point. Thank you!
Good vid but one correction, you are in voltage mode, so you are not "getting current from it". Current is when you complete a loop and draw current through a load. Technically a meter is a load, but it is designed to draw as little as possible, so this is not a current but a voltage test. It is, however, good advice. You should see voltage only between Red and C wires but not between C and any other wires. In addition, you should see voltage between red and basically every other wire (W,G,Y). Note the meter is in AC voltage mode and should read around 24V.
R g
Just an FYI if you remove a thermostat while the unit is running and replace the thermostat with the stat still calling for function, it may pop the fuse on the circuit board.
GREAT tip!!! Thank you
What do I do if my c wire isn’t showing any power coming from it?
C (common) wire is a bit confusing, its referred to as if it's a hot wire that provides current, when in reality its a return wire that completes the circuit from the red hot wire... what is even more confusing is that smart thermostats need it and instructions also refer to it as if were a separate source of 24v
If it hooks directly into the C terminal on the board, then that's a direct 24v source, not a loop from another wire.
@@n.g.1577 figured it out after much confusion.. wished they just called plain and simple- a hot 24v source.. "C wire" is too misleading... My furnace didn't have a C wire connector, so I tried tapping into the existing 24v hot but the load was too much.. so I installed another 24v transformer to solely power the thermostat C connector.
@@toofargone10the c-wire is the “neutral” wire of low-voltage system.
No. C wire is 0 volts, or ground. @@n.g.1577
my current wokring thermostat wiring has the blue wire on G, and I'm trying to install smart thermostat. Should I simply keep the same wiring or put the blue wire on C.
Sorry for the newbie question.
What happens if I touch the red pen to "R" and the black pen to "C"?
Will be the value 0 or -27?
Because I don't have C-Wire, I purchased a 24v transformer Wall adapter from Amazon.
Maybe because Chinese brand or a cheap brand, it doesn't have any mark which one is for C or R. I want to test with a multimeter before just guessing and plug to fry out my furnace. I like to know what kinds of results I get if I test in the opposite way.
Thank you.
Because it's AC, it will still read +27 whether you put black to R and red to C or black to C and red to R. Polarity makes no difference in an AC circuit.
What setting on dial of the multimeter do you put it on?
lowest VAC setting around 50 or auto
it has to be alternating current is all that matters.