“How do I know if I have a C-wire in the wall where my old Honeywell thermostat was? Is there a way to make this work if I do not have a c-wire?”
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You can use the fan or “g” wire to Power it.
Sorry, there was a problem. Please try again later.I would like to shed some light on this question. SHUT OFF ALL POWER to ALL THE HVAC indoors and OUT just to be safe. The "C" wire as most are naming it is the Common Wire, think of the common wire as the negative end of a battery, positive on one side negative on the other, you need to complete the circuit to make the device work . Older thermostats did not need this Common wire because they acted like a standard light switch, common wires are tied together and bypass the switch. Because this device has light and other circuitry requires a complete circuit to operate. Any color can be used as long as it is not in use for something else. These are the standard colors and what the control. RED = +24 volts A/C, White = turns on the Heat, Green = turns on the Fan, Yellow = turns on the A/C compressor outside. Pull the wires out a little from the wall you may find a couple of extra wires wrapped around the thermostat cable that you can use as a common wire. If the common is not hooked at the furnace/air handler you will need to hook it up to all the other commons which should be the most amount of low voltage wires twisted together, if you are not sure call a professional as the wire colors coming off of the transformer will not make sense to the average person, hooking up the wrong wires can DAMAGE control boards and other internal devices!
Sorry, there was a problem. Please try again later.My thermostat for this installation also lacked the c wire so I had to choose between the work around provided by Honeywell or bring in a pro to rewire the connection. Opted for the professional installer, but would have saved $400 on the DIY. Know that the workaround means you'll lose manual fan control, but the fan runs fine when the system calls for heat or cool (just can't run only fan or fan in circulate mode). Great product and the fifth gen I've installed in various homes over the past few years.
Sorry, there was a problem. Please try again later.I wanted to upgrade old, battery powered 4 wire thermostat to a 5 wire smart thermostat. My current installation has a humidistat located about 3" above that thermostat. There was no "C" wire connected to the old thermostat, but there was a blue wire attached to the humidistat. I applied a multimeter across the RH wire in the thermostat and the blue wire in the humidistat and discovered to my delight that it was a 24 volt circuit (C wire). So I simply spliced into it with a wire nut and ran connected the blue wire to the C terminal in the thermostat. Problem solved!
Sorry, there was a problem. Please try again later.You should be able to snap the front of your thermostat off the baseplate and examine the wiring of your current thermostat. You can see if it uses C or if there is an unused wire in the multi-conductor cable that runs to your furnace. There are good videos on the Honeywell site referenced in the Quickstart guide.
Sorry, there was a problem. Please try again later.When you look at the wiring on your current thermostat, simply check to see if the terminal block marked C has a wire running to it. Or if there is a terminal block marked C. If not then you do not have a C wire. Lots of homes do not. There are some workarounds but it may not be easy. Google C wire and I am sure you will find lots of advice.
Sorry, there was a problem. Please try again later.The best advice I can give you is to contact their tech support group before you purchase. I did this and they resolved my concerns prior to purchasing and the install went well. The C wire is needed to power the thermostat, and there are other options, I read it in the book. But I have a heat pump, with aux heat, and even in this configuration, this thing was a breeze to install.
Sorry, there was a problem. Please try again later.If you remove the old thermostat and there is a 5-wire cable, the blue wire is used for the "c" or common wire. This wire may not be connected or connected to a different point.
Sorry, there was a problem. Please try again later.You require a common wire (C wire - usually blue) to power on the unit since it does not take batteries. I think there is a workaround, but you need to call Honeywell support to make sure.
Sorry, there was a problem. Please try again later.You well dictate this from the wall ..
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