Replacing a 2 wire thermostat with a 4 wire
grasswhacker
16 years ago
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bigbird_1
16 years agoterribletom
16 years agoRelated Discussions
Replacing a Thermostat Wiring ?
Comments (3)Rc and Rh are heating and cooling power from the 24V transformer in the furnace and they are usually connected together, except in some heat pump systems Your new digital thermostat will probably have a terminal labelled C which goes to the other side of the 24V transformer in the furnace and that will enable the furnace to power the thermostat, or keep the batteries in your thermostat charged so that you don't have to replace them. It's a necessary connection if your new thermostat has a backlit panel The G wire is to turn on the furnace blower fan The Y wire is for the condenser relay which energizes the A/C compressor The W wire is for the relay which activates the furnace You should be able to operate most single stage heat and single stage cooling setups with those 5 wires - R, C, G, Y, and W Hope this helps, Don...See MoreNew wifi thermostat and wiring issues with C wire
Comments (20)I climb up the attic open the door at furnace and find out there is a transformer that step down 120 v to 24 v . and two terminals at the second end (24v) red terminal is power 24v and the other terminal is use to connect to frame or chassis and serve as common ground so a c wire is any unused wire you can pick any color you want in the same bundle that goes from the furnace to the thermostat in my case those extra wires are trim flush to the bundle jacket on both end so I need to peel that jacket off about 2 inches on both end and connect a single wire about 2 foot long from the frame to the wire you selected (let say black) on the furnace end then the black wire on the thermostat end will be "C" wire and connect it to the "C" terminal on the new wifi fancy Honeywell or Nest. If I say anything wrong please correct me. I will do this at some other time. for now I just thinking. I signed up for smart (something) at gapower.com and they will sent me a nest gen.3 for free. I think this nest also will need "C" wire. I wait till I get the Nest then I will install both the Nest and the Honeywell at same time I will put the Nest down stair and Honeywell up stair....See Morethermostat 2 wires to 5 wires
Comments (1)I have two Honeywell Vision Pro thermostats that use the Redlink system to communicate wirelessly. There's an accompanying part called an Equipment Interface Module (EIM) that's mounted to a wall adjacent to your equipment. The 6 wire or however many connection your equipment needs is wired from the equipment to the EIM instead of being run to the thermostat. The EIM then communicates wirelessly to the thermostat, using Honeywell's Redlink radio frequencies and not using Wifi. You can use the 2 wire run for power only, or even mount the thermostat anywhere else because it will fun for months on battery power only. The Vision Pro system, which is not the newest model line. offers full remote access over the internet with very easy to use apps for Android/Apple. Or, you can even access your thermostat from a PC or generic tablet using a browser. You can change the temperature setting, reprogram or set any or all of the setback times and temps, etc. I find it easier to change the schedule using a remote control than by standing at the thermostat. It operates flawlessly without any glitches or problems. It has reset itself immediately after several power outages. It may be the newer Wifi equipment, which I'm not familiar with, will also work with an EIM. The EIM was designed explicitly for situations where rewiring may be complicated or undesirable to do....See MoreThermostat going 4 degress higher. Swing was set. Need wire help.
Comments (13)The big reason to use solid vs stranded wire is that solid wire is easier to thread into those terminals. With stranded wire, there can be a problem if a loose strand manages to contact an ajacent terminal. More likely because the terminals in a thermostat are so close together. Just had a problem with our thermostat. It started running 2 degrees past set temperature. (I have it set for a 2 degree temp differential because the heater was constantly kicking on, running for just a bit and then kicking off...which was driving me nutz.) After a bit of sleuthing, I found that the caulking backer rod that I had shoved under an exterior door (across the room from the thermostat) had become unwedged and there was a significant draft from underneath the door. (The backer rod was supposed to be a temporary fix that I did a couple of winters ago but forgot all about it...) Once I got that hole plugged up (with a better temporary fix), the thermostat quit heating past set temp. I don't know for sure if the draft was the reason the thermostat got weird or if it was a coincidence.... Whatever, I did buy a new thermostat to replace the old one but haven't installed it since the problem seems to be resolved. Just tossing my recent experience out there as a potential cause because a new therm hasn't fixed your problem. (Yes, I know my thermostat is in a poor location and should be moved away from drafts from opening/ closing exterior doors. Just no good or easy place to relocate it to and it's a low priority problem.)...See Morebigbird_1
16 years agograsswhacker
16 years agograsswhacker
16 years agobigbird_1
16 years agograsswhacker
16 years agobigbird_1
16 years agograsswhacker
16 years agocobraguy
16 years agograsswhacker
16 years agobrickeyee
16 years ago
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