What do thermostat wires mean

The main difference setting each apart is the number of colored wires. HVAC systems with more functions need more wires to communicate to and from the thermostat. The 5 strands of wire provide enough functions for the modern thermostat. The most common benefit of having 5 conductors is being equipped with a common wire, known as the c wire. Read reviews and find the best prices on Amazon.

Wiring a thermostat is basically connecting the correct-colored wires to the correct terminal. Understanding what each wire is for is critical to complete the procedure successfully.

If you are unsure of any of the thermostat wiring, it is safer to contact a qualified professional. The wiring for thermostats can be configured in a variety of ways. The most popular ones, which range from 2 to 5 wires are covered below.

If you have more than 5 wires, you have more control points or you have a heat pump. If you have two wires, you almost certainly have a digital thermostat that solely provides heat i. My old thermostat has 8 wires, all hooked up. What do I do? Hi Mark please provide the labels on the old TT and Type of system you have for heating and cooling.

Hello, I have a new home with a Payne forced air furnace. I replaced the cheap thermostat with a Honeywell thwf All wires were hooked up on the thermostat to their corresponding colors including the Blue Common wire. At least when I explained it to Honeywell that is their thought.

When I look at how the furnace is wired I have the following wires on the following terminals. You need to buy a 24 volt power supply to power the thermostat. When the house is big, all you need is circulation. So if you the fan keeps on running, then it will keep circulating the air to maintain an even temperature.

I see speak about 24v transformer…if I have a C labeled spot on my furnace will that automatically be supplying 24v…or would it need an inline voltage transformer? Thanks, great write up. My house had old wire No C wire Which is the common wire…or known as ground.

I installed a crude programmable battery operated thermostat years ago. Now That theyre wifi they need a constant source of power. I had an electrical outlet just a couple feet from my thermostat. I used a meter and verified that my unit is commonly grounded with my house of course it should be I simply ran a single wire from the earth ground off that plug with a small wire and up the wall to the new thermostat.

Keep in mind the red is 24VAC control. Your new thermostat already has a rectifier built into it. Why is not everyone doing that? I did the same thing except I completed the circuit using the white neutral wire found inside a switch box that is 2 feet from my thermostat. These neutral wires are what return all of the AC circuits in your home — the ground wires are only there in case of a power surge or other emergency.

Tying into the ground wire could get you electrified plumbing or other consequences. I have a furnace that has a white wire connected to the c connection inside the furnace. At the thermostat the white wire is W. I also have a yellow wire free at thermostat and furnace. Can I connect the yellow at furnace level with the white already connected and use the yellow at the thermostat for the C connection? And yes you can use that yellow wire along with white to C terminal on furnace. At the beginning of the summer, I installed a Z-wave thermostat.

I have only 4 wires that were marked R, W, Y, and G. There was no Common wire. The good news is that it worked perfectly all summer. But now it is heating season… Evidently I mistakenly connected the W wire to the C, and this allowed power to the thermostat for the display.

Again, everything worked. Until it was time for heat, and then the heater would not come on. I moved the wire from the C terminal to W, and now it will heat but the thermostat display does not come on. I guess I have two questions: 1 why did this work at all? Thermostat C Wire: Everything you need to know about the … […]. Blue or Black — C — Common wire, may be unused by your existing thermostat. Enables continuous power flow from the Red wire.

Thank you SO much for this article. I really appreciate you putting this together! Best Wifi Thermostat Reviews The ultimate resource for …Smart thermostat guide — wifi-enabled thermostat reviews, The ecobee3 hands smart thermostat today. Smart Thermostat Guide — Wifi-enabled thermostat reviews …Thermostat wire: , Saying wire power source, supplies power misleading.

Am I doing something obviously wrong? Thermostat C Wire: Everything you need to know about the …New wifi thermostat wiring issues wire — houzz, New wifi thermostat wiring issues side -wire […]. I installed my wifi thermostat using the techniques mentioned in this article. I have one question. When I set the fan to that setting the fan comes on to circulate the air only but the heat comes on as well.

Is that possible? G goes to a gray wire again a solo connection. I purchased a new thermostat that I plan on installing tonight. My question is related to the power though.

Is it completely necessary to turn off the furnace power and breaker switches tied to the thermostat? My home is old and unfortunately the breaker box did not label which each switch controls. Let me know when you can. Read more about the C-Wire here. Sorry for adding more questions your way but I enjoyed reading the previous ones you helped trouble shoot. Can we still intall the new or do we need to add other wires? I am afraid of burning the unit.

Please help. Connecting new HoneyWell thermostat to old Lennox furncase. The old thermostsat had a C wire connected but probably not used — it was battery powered. The C wire is connected to the cabinet ground at the furnace. When I attach new thermostat it does not power up.

I think the blue wire in the diagram comes out as the red wire to the thermostat. Should I disconnect the C wire from the cabinet and connect it to the yellow wire on the transformer? Hi all, This site is really helpful I think but I want to make sure I am not getting myself into trouble.

I have a two wire R W right now, but the builders helpfully installed a multi wire cable despite not using most of them. So I think running a C wire should be as simple as attaching my Blue at both ends.

That S87B does have something marked as 24v which is actually connected to my White wire. Does this seem right? Is my C the legit place to connect? The wire connected to R on your thermostat should be the 24 v and usually Red. W usually white activates heat. The C wire is the common which is the return to the opposite side of the transformer from which the 24v wire comes, completing the 24 v power for the thermostat. Hi My dogs chewed up the wires outside of the ac unit.

Out of the fan comes out a blue and yellow wire. Out of the wall comes out a red a white wire. Which wire would go with which wire? I have 2 wires going to my thermostat. Using the voltmeter, I get 28V and when the heater turns on, they are connected, so it shows nothing. Does this mean I can jump one of these wires to create a common wire?

If so, how do I know which one is the common and which one is the hot wire? I am interested in installing a smart thermostat but lack the c wire at the thermostat.

I have 2 thermostats. The Ecobee has a PEK kit that you can install at the boiler to effectively create a c wire there. Any help? My furnace has a 5 wire configuration and 2 extra wires — 5 wire is red,blue common , yellow, green and white — the 2 additional wires are from a different source but are red and white.

I am installing a Honeywell EIM and it is not powering on. The common and red from the 5 wire source are not showing power on a volt meter. I checked breakers, the furnace shows it is powered. Configured the EIM exactly as the wires were configured in the furnace.

I have a blue red white and green wire with a jumper wire. I have no C wire, and its just a milivolt heat gas fire , which just closes the contact for heat.

Removed the link between RC to R important. Connect the existing milivolt connection from gas fire to R and W and hey presto , works a dream. Thanks for all the information on your site , very useful this is how i worked it out. Thanks a lot for writing this article. I replaced my old thermostat with a Nest 3rd generation.

I hooked everything up as instructed but could not get Rh to have a higher voltage. It was reading around 2V for VOC. I called Nest support, but they were not able to help. I almost had to call an HVAC technician to come out before reading your page. It turns out the old thermostat had all the wires connected, but the furnace only had W and R wires connected. I connected C, G, and Y to the appropriate connectors on the furnace, and voila! So thank you so much for this article!

I have a two wire boiler quite old and dated that is hooked up to a basic thermostat in my family room. The Thermostat for this is upstairs on the second floor. If I wanted to upgrade my thermostat in my family room to run both systems, is this possible? Where would the C wire need to come from?

This site is incredibly helpful. I knew I was in trouble when I opened the thermostat and realized I only had a mechanical switch with just a two-wire thermostat wire, red and black wire on a heating system only. I closed it back up, and began research. I do not know what I am going to encounter when I look at the furnace circuitry, but I am going to armed with wire.

I intend to test new thermostat at the furnace with the solutions that you have given me before I try to pull the new wiring. Do not know if I will need a separate transformer, but this site has done a wonderful job for preparing me for what I am up against. Thank you, thank you. It has a Carrier digital thermostat that my mother-in-law has continuous problems figuring out how to set it.

I purchased a Honeywell CT31A non programmable therm. He gave me a model CT51 which he said could be used.

Is this something you would agree with, and could I be confident in wiring this in this configuration less the C wire with the results being that of working properly. Looking to get this replacement completed before the next need for heat LOL. Thanks for any feedback you can send my way. With Regards, Tommy E. I have a Honeywell wifi thermostat set up.

I have a generator wired to power several circuits in my house in case of power failure wired the right way as to avoid arguments. Actively scan device characteristics for identification. Use precise geolocation data. Select personalised content. Create a personalised content profile. Measure ad performance. Select basic ads. Create a personalised ads profile. Select personalised ads. Apply market research to generate audience insights.

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