“Hi. I have a regular Honeywell thermostat. I know for sure it uses AA batteries. Does this mean that I don't have c wire and then I won't be able to install the new smart thermostat?”
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You will need to confirm if you have a common wire or not. You can not tell simply by the thermostat needing batteries or not. Some thermostats used the batteries for display illumination or to hold the program memory in case of a power outage.
Sorry, there was a problem. Please try again later.No necessarily. Many thermostats, including some Honeywell thermostats use batteries as a backup. I just replaced 2 relatively new Honeywells with these and they used AA batteries but there was a "C" wire, too. You really have to take the existing thermostat off of the wall to see if there is a "C" wire available.
Sorry, there was a problem. Please try again later.My understanding is this is going to be the case with all WiFi thermostats. You can still use it but you will have to change some wires around on your furnace. This unit does not run on batteries. Depending on the wires you have available you may lose access to manual fan control (running fan when ac or heat is not on). The fan still works but is only system controlled. I did. You end up using the G wire at the thermostat as the C wire. You then have to take the Y wire and switch it to G at the furnace and jumper Y. The instructions included with the unit point you to their website for these instructions. You can also buy adapters or have someone rewire your system. If you do decide to use the jumper method be sure to turn off power to the system first.
Sorry, there was a problem. Please try again later.The older thermostats often use AA batteries to light up the LCD panel or maintain the programming in case of a power outage so that is not an indicator of having a C wire or not. The only way to know is to take your old thermostat off of the wall or go to your furnace and check the number and colors of the existing wires. My old thermostat did not use a C wire but the bundle of wires in the wall did contain an extra unused wire. (It was pushed way back into the wall.) Unfortunately, it was not connected at the furnace so we had to connect it there before the C wire could be connected and new thermostat would function properly.
Sorry, there was a problem. Please try again later.The C wire can be hidden behind the thermostat as some older units don't require the c wire and its hidden behind in the wall. Just like most modern residential units the brown, orange, and black get tucked back behind into the wall as there is no heat pump or emergency hvac systems in most homes.
Sorry, there was a problem. Please try again later.The C wire is probably not connected to the old thermostat if it has batteries. If you have single stage heat/cool and the R and Rc wires are not separate then the old thermostat probably uses only four wires(W,G,R,Y). If the thermostat cable has an extra wire (mine has five), then connect the extra wire to the C terminal at the furnace/AC, as well as at the thermostat. If there is no extra wire, then replace the cable or purchase a plugin adapter from Honeywell that supplies 24 VAC to the thermostat.
Sorry, there was a problem. Please try again later.Check your wire bundle for an unattached wire wrapped around the bundle. You can use that wire as your C wire. You nust then go to your furnance and find that same wire and connect it to the C terminal on the furnace.
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