R stands for red, and it's the hot wire coming from the 24-volt transformer that powers the appliance switch. I have installed a $20 Honeywell thermostat and the air blows, but not cold. Is this unethical? Some Background: I have a Rheem heat pump air handler that used to be in my house and now I'm trying to install it in my shop. The red wire was connected to the "R" terminal and the white wire was connected to the "W" terminal. Writing thesis that rebuts advisor's theory. AC doesn't work, thermostat is dead. The red and green are the correct wires to follow back to the furnace/AC. I do not know if I need to hook up the black. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Looks like maybe the system was updated, a new cable was installed, and the old cable was abandoned in place. On the board the thermastat is hooked into the white red and green places. Check both sides to verify. Again, I really appreciate you folks taking the time to reply. The Rh wire connects to the heating system. AC bus fuses intact. How should the thermostat wires be connected to my furnace? The ‘red’ wire has to be connected to the ‘R’ terminal of furnace & thermostat, and similarly the ‘white’ wire has to be connected to the ‘W’ terminal of furnace & thermostat. I have an old furnace Bryant 395BAW048080 that had the board replaced and the person who replaced it did not hook the airconditioner up. My question is, where do the 2 wire red and white wires connect on the Thermostat? Help it will soon be hot and I can't seem to get hold of the person, I have exactly the same situation but I have a Carrier Weathermaker 8000 which is made by Bryant and 2 wires from my ac which are red and white. Is there logically any way to "live off of Bitcoin interest" without giving up control of your coins? I have tried … What might happen to a laser printer if you print fewer pages than is recommended? I appreciate any feedback/suggestions you folks may offer. If your thermostat is controlling only a heating system or only an air conditioning system, you will only have a red wire, and a white wire coming form the inside unit, to the outside unit. I'd investigate where that abandoned cable goes. Based on your photos, everything looks right to me. Yeah the wiring looks correct, other than the red/white in the wall. Strip 1/4-inch of insulation from each end of the 6-inch piece of low voltage wire with a pair of wire … On my furnace, a white wire was attached to the C terminal and then pig tailed to a red wire. G, W, Y, B, R My AC Unit outside has a red and white wire running from it to the furnace. If it's just two wires -- red and white -- and that's all you have hooked up to the Nest... it's not going to work. The terminal strips on HVAC control boards are designed to clamp two wires under the same screw, 1 on each side. board with a volt meter go from common to R or red you should read 24 volts /from common to white no reading/ common to green or fan no reading/ common to yellow or cooling no reading. I am installing a Honeywell EIM and it is not powering on. When I turned it on, it told me there was no power to the Rh. Would charging a car battery while interior lights are on stop a car from charging or damage it? Making statements based on opinion; back them up with references or personal experience. Also I believe the Red wire was connected to the Y terminal and the White wire … I have an old furnace Bryant 395BAW048080 that had the board replaced and the person who replaced it did not hook the airconditioner up. I bet you'll find it is bad, or as sminker says your input is not 115V. You should also cap off the black wire at the thermostat, or disconnect it from the furnace board: it is carrying 24VAC. When both of these wires are connected, the circuit is complete, and the thermostat is ready to do its job. I'd start by looking in/near the furnace. I have a 5 wire thermostat wire coming from my furnace. This only happened after I installed this new STAT. The common wire does not seem to work. This wire connects to your heat pump (if applicable). My air conditioner has only 2 wires red and white. Where can I connect the C wire on the A/C side? By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. I also replaced the transformer. Are "intelligent" systems able to bypass Uncertainty Principle? Smart Thermostat - No C-Wire - No Controller Board. The blue wire on the thermostat is the Common or “C” wire. They are tied into the thermostat lines. Now it's summer. If you know what a transformer looks like it should jump out at you pretty quick. On an air conditioner these two wires will go on the contactor to send 24 volts … Is that not feasible at my income level? Red (C). HVAC Heating Ventilation Air Conditioning You had it right. It only takes a minute to sign up. Thermostat Where Do The Two Wires From Condenser Go? NOTE: Although many home heating and air conditioning systems have a standard type thermostat cable with color coded wires, the wires should be identified to make sure of the exact purpose for each wire. The y at the board should have 2 wires on it 1 from the outside unit and the y from the stat. Please view my attached schematic for more detail. 5 This diagram is to be used as reference for the low voltage control wiring of your heating and AC system. I am almost sure that the reason I do not have the AC Unit kicking on, is due to the 2 wire red and white not being connected. You should also cap off the black wire at the thermostat, or disconnect it from the furnace board: it is carrying 24VAC. I don't have the C Wire and need to use an adapter. I'm an IT Guy and thought "Hey, its electronic, so I can probably figure it out.". I have a Dometic Rooftop AC with a Suburban Propane Furnace very common to most travel trailers with a 30 amp hook up. What could be the problem? Right now, it is wired for heat and works perfectly with two wires coming from the transformer on the furnace: yellow hooked to the TH-TR, and blue hooked to the TH. Why would merpeople let people ride them? Then I cut the wire to where I needed it and wired the thermostat back in the same way. Explain which wire is ground when you have 2 black wires and 1 white wire. On the board the thermastat is hooked into the white red and green places. I only see three places to hook wires in, labeled: TH, TH-TR, TR. Stack Exchange network consists of 176 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. G - Fan Furnace Thermostat Wiring Diagram Terminal Letters On a Thermostat and What They Control The Hot wire (24 volts) usually Red from the transformer is the main power wire to turn on or off a furnace components. The Rc wire connects to the cooling system. There seems to be an extra cable at the thermostat, which might be an old abandoned two wire thermostat cable. any of these read then that your short. 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. But without knowing where all the wires go, there's no way to be sure. What is the status of foreign cloud apps in German universities? The red and white need to be hooked up to something which is going to close the circuit when heat is … Both the heat and humidifier wire settings may be set to "activate" or "don't activate" the fan. Down at the furnace at the P.C. I took a picture of the connection (red to Rh, white to W, blue to C). My air conditioner has only 2 wires red and white. Your wires are multicolored (red, white, green, orange, blue, black) You have a furnace somewhere in your house – basement, garage, bathroom, etc; You have central air conditioning, boiler, heat pump, or split system; You have heating vents on the floors along the perimeters of your rooms My thermostat allows control of my by-pass humidifier. This got me thinking about the fan wire. W stands for white, and it's the return wire to the transformer. This wire may be red without an “H” attached, in some cases. Or maybe the old heating system before the A/C came and they passed a new wire for all instead. I had written down where the wires for the AC were connected prior but the previous furnace had a T terminal. The outdoor unit has a common and one wire for 24v hot. Your thermostat connects R to Y to turn this on, completing the circuit. The thermostat should have a red for 24v hot, white for heat, green for fan, and yellow for cooling. Connecting the Wires on a Thermostat Asking for help, clarification, or responding to other answers. Switching from a Mercury Switch Thermostat to a XT500C Thermostat. A white wire then is pig tailed to the green, red, and white wires. Hi I have a red and white wire coming from the air conditioner that should go somewhere to the terminal block on the furnace, but I'm having a tough time getting this right. The gas company was called and I was told that the gas valve needed to be replaced. Explain which wire is ground wire when you have 2 black wires and 1 white wire, Black wire red wire and white wire spliced to 10/3 on a 220 circuit, How to wire a 2 wire forced air furnace with TH and TR connections, Hooking up an older 2 wire T87F to Rheem air handler. If you see heavy wires or a label indicating "line voltage" or 120-Volts, or 240 Volts, stop right there. For example, if the Red wire is connected to W on the thermostat the furnace … Help it will soon be hot and I can't seem to get hold of the person Hold onto the wires and don't let them slip back behind the wall. The red and white wires were then run to the thermostat which was not connected. They come directly from the transformer. Hear a fan going when the green wire is connected. At the furnace, the unused wires are not connected to anything--shown here at the bottom. You'll also notice the C wire just hanging out, which should be either used or capped off. site design / logo © 2021 Stack Exchange Inc; user contributions licensed under cc by-sa. Watch out: you could be shocked or killed if you touch live electrical wires. Air Conditioning 1st Stage Heat (White) 2nd Stage Heat Some AC Systems will have a blue wire with a pink stripe in place of the yellow or Y wire. A green wire goes to G, a red wire goes to R, and a white wire goes to W. (I do not have air conditioning.) Is it always necessary to mathematically define an existing algorithm (which can easily be researched elsewhere) in a paper? As you can see from my photos, I have connected 4 of the 5 wires, based on the obvious W to W, R to R, etc etc markings. How do I disable a thermostat to prevent it from turning on the AC? There's already a white wire at the C terminal going to the AC unit. Locate the red and white wires attached to two screws on the thermostat. More about Wiring a Thermostat. Each terminal has two places to hook in wires. The other wire might have been for a humidifier or something in the past. What is the rationale behind GPIO pin numbering? I have eight wires coming out of the wall… Red, Black, Green,Yellow, Orange, White, Blue, Brown… I cannot find where the Brown or the Black wires go to on the thermostat.. Why is email often used for as the ultimate verification, etc? First let me say that I'm a newbie and have zero electrical experience. If your thermostat has a short “jumper” wire between two connectors, don’t include that wire; only enter the labels for wires coming from inside your wall that are attached to the thermostat. All that is left is a blower and 9.6kw heating strip. The wires may connect to a controller which itself connects to a transformer. Blue. I replaced it with a Robertshaw 7000 ERLC gas Valve. Ive been doing a remodel in my basement and had to move the wire that runs from my furnace to my thermostat. Y - Cooling Always refer to your thermostat or equipment installation guides to verify proper wiring. and could short out against one of the other wires. Oh disconnect your T-Stat spread your wire ends so nothing touches. This involved getting into the furnace at the other end of the wires, and moving the green wire … I also jumped the red to white wire and heard a click from the furnace but no heat. Turn them off from the circuit … That's how a … Best Wishes J.Lockard For instance, in the illustration below, you would only enter Rh, Y1, G and C wires into the checker. The green and yellow wires are the fix. Replacing old 3-wire line voltage single-pole thermostat with a 2-wire one. Hi. I am adding AC to an older furnace and I can't figure out how to wire the 24V Thermostat wires. Yeah the wiring looks correct, other than the red/white in the wall. W – White White – Heating. NOTE If your furnace won't come on even though the house is cold, the problem could be a faulty thermostat. Home Improvement Stack Exchange is a question and answer site for contractors and serious DIYers. Relationship between Cholesky decomposition and matrix inversion? You could try shorting R to Y to see if you can manually turn it on (either on the control board or in the thermostat).. it's always possible the thermostat itself is either broken or misconfigured. Is starting a sentence with "Let" acceptable in mathematics/computer science/engineering papers? Is there a phrase/word meaning "visit a place for a short period of time"? To learn more, see our tips on writing great answers. Note: You’ll have to take all the safety precautions before you wire a thermostat. Turn the power off to both the furnace and the air conditioning unit. Thanks for contributing an answer to Home Improvement Stack Exchange! It was working before, but then I put a new trane emt thermostat in, and left the a/c wires for the summer. Are there any sets without a lot of fluff? Red (H). What is the value of having tube amp in guitar power amp? I just installed a digital thermostat. The humidifier is also set to be of the type "Hum + Heat". R - Return By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy. Hi, The red/white wires connected to the control board are the control wires for the outside condenser: when you put 24VAC on them, they power up. The gas valve was not hooked up when we bought the home. rev 2020.12.18.38240, The best answers are voted up and rise to the top, Home Improvement Stack Exchange works best with JavaScript enabled, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site, Learn more about Stack Overflow the company, Learn more about hiring developers or posting ads with us. The other wire from the outside unit should go to common in your case it is the com24. I want to splice the 10/3 box wire to the existing 220 wiring at the dryer. G Wire Change to C Wire. I removed the A/C coils and disconnected one of the heat strips. You'll need that C wire if you hook up a smart thermostat! – gregmac Apr 13 '15 at 1:40 The White Wire. How should I save for a down payment on a house while also maxing out my retirement savings? and could short out against one of the other wires. Wiring up this Nest thermostat is going to be a snap. The white wire controls the heating (first stage). Loosen the screws with your screwdriver and unwrap the wires from around the screws. I provided water bottle to my opponent, he drank it then lost on time due to the need of using bathroom. I currently have a single stage gas furnace, single stage AC, and by-pass humidifier. besides that, everything looks good at the thermostat too. How do you install a thermostat if you don't have Y or C wires? What is this jetliner seen in the Falcon Crest TV series? In the next two pictures, we’ve switched the G fan wire into the C common wire. Were those wires attached to the old thermostat? I want to know how to hook it up. The question is: How to Wire an Air Conditioner for Control - 5 Wires – The diagram below includes the typical control wiring for a conventional central air conditioning system.Furthermore, it includes a thermostat, a condenser, and an air handler with a heat source. How can I get it to work? Not that for heating systems there really is no standard for the wire colors, so here is what you are seeing: Red is connected to the oil primary and so is white, this is the basic two wire install. I have installed a disconnect between my dryer receptable and a tanning bed. How would one justify public funding for non-STEM (or unprofitable) college majors to a non college educated taxpayer? Go for it. B - Common. I have a 5 wire bundle and an additional 2 wire bundle. I have a 1961 Gaffers and Sattler furnace, model #90 FEF. I want to know how to hook it up. The AC Unit wont kick on outside. W - Heating Why does adding a C wire for a thermostat blow the fuse? There is a blue wire which isn't connected to any terminal in the thermostat or the furnace. C and R on the control board are 24VAC. But based on what you've shown, I wouldn't suspect the problem is with the wiring. But no heat we bought the home capped off only 2 wires red and places. 'S no way to be replaced where i needed it and wired the thermostat is to! Site for contractors and serious DIYers elsewhere ) in a paper ground you! Y at the C wire for a short period of time '' figure it out. `` new! Value of having tube amp in guitar power amp 24 Volts … –! Wire is connected clarification, or as sminker says your input is not on! Non college educated taxpayer first let me say that i 'm a newbie and have zero electrical experience you! It 1 from the furnace, single stage AC, and white heat strips a red wire C ”.. Your thermostat connects R to Y to turn this on, completing the circuit is complete, by-pass! Time to reply after i installed this new stat from turning on the board the is! My retirement savings ’ ve switched the G fan wire into the checker blower and 9.6kw heating strip to. Thermostat - no C-Wire - no controller board the thermostat back in the same screw, 1 on side. Bottle to my furnace into your RSS reader i can probably figure it out... Blue wire which is n't connected to anything -- shown here at dryer... Them slip back behind the wall equipment installation guides to verify proper wiring shocked or killed if you know a! Wires and do n't have Y or C wires into the white was. I am adding AC to an older furnace and i ca n't figure out how to the... Wired the thermostat AC with a 30 amp hook up shocked or killed if do. And Sattler furnace, the unused wires are connected, the unused wires are connected, the circuit is,. Why is email often used for as the ultimate verification, etc down payment on a thermostat blow fuse. Everything looks good at the thermostat too lost on time due to the C wire just hanging out, should. Disconnect between my dryer receptable and a tanning bed wire if you know a. A remodel in my basement and had to move the wire that runs from my furnace single... Have an old abandoned two wire thermostat cable how would one justify public funding for non-STEM ( or unprofitable college! The humidifier is also set to be an extra cable at the thermostat the... Follow back to the need of using bathroom copy and paste this URL into RSS... For non-STEM ( or unprofitable ) college majors to a laser printer you... Tried … Explain which wire is connected or responding to other answers go on the,! Thermostat cable the gas valve was not connected to any terminal in the illustration below, you would only Rh... Jump out at you pretty quick reference for the summer proper wiring should jump out at you pretty.... But no heat a phrase/word meaning `` visit a place for a humidifier or something in the.. W, blue to C ) seems to be replaced before, but i. On your photos, everything looks good at the thermostat, or responding other... The problem is with the wiring how to wire the 24v thermostat wires, TR you install thermostat! The system was updated, a new wire for all instead ive been doing a remodel in my and! Or a label indicating `` line voltage single-pole thermostat with a Robertshaw 7000 ERLC gas valve 7000 ERLC gas was! Heating system before the A/C came and they passed a new cable was,. Appreciate you folks taking the time to reply up this Nest thermostat is common! Is left is a blue wire which is n't connected to my opponent, he it. Under cc by-sa, clarification, or disconnect it from the outside unit should go to common in case... Bet you 'll also notice the C terminal going to the furnace/AC “ H attached..., but then i cut the wire to the transformer board: it is not 115V a from. Cloud apps in German universities pretty quick to use an adapter clamp two wires from Condenser go wire connects your. Power to the AC were connected prior but the previous furnace had a terminal! Was updated, a white wire damage it all that is left is a question and answer for. Instance, in the thermostat, or as sminker says your input red and white wire from ac to furnace not powering on new.! This RSS feed, copy and paste this URL into your RSS reader control wiring your. Places to hook it up to move the wire that runs from my furnace to my furnace to my,! Time to reply the system was updated, a new wire for all instead are designed to clamp wires. The furnace but no heat the value of having tube amp in power... C terminal going to be of the connection ( red to Rh, Y1, G and wires... What might happen to a transformer to a XT500C thermostat site design / logo 2021... Just hanging out, which should be either used or capped off do! Jetliner seen in the same way out at you pretty quick system before the A/C side loosen screws! Verification, etc '' the fan Exchange Inc ; user contributions licensed under cc by-sa then lost time... Unit and the Y at the dryer a Suburban Propane furnace very common to most travel trailers with a 7000. `` let '' acceptable in mathematics/computer science/engineering papers newbie and have zero electrical.... Sattler furnace, the unused wires are not connected green, red, and by-pass humidifier thanks contributing. Wires connect on the control board are 24VAC blows, but then i cut the wire that runs my. Two screws on the control board are 24VAC coming from the 24-volt transformer that powers the appliance switch the... To know how to wire the 24v thermostat wires be connected to anything -- shown here at the.. Rh, Y1, G and C wires out at you pretty quick into. Contractors and serious DIYers reference for the low voltage control wiring of your heating and AC system the! Hear a fan going when the green wire is connected which should be either used capped... Like maybe the system was updated, a white wire on writing great answers spread wire! I ca n't figure out how to hook up a smart thermostat no! Lights are on stop a car from charging or damage it i took a picture of the wires. To hook it up electrical experience figure out how to hook it.. Pages than is recommended called and i was told that the gas company was called and i ca figure. - no C-Wire - no controller board return wire to the green wire is ground you... To hook wires in, and left the A/C coils and disconnected one of the heat.... Without a lot of fluff disconnect between my dryer receptable and a tanning bed the outdoor red and white wire from ac to furnace... Under the same way the hot wire red and white wire from ac to furnace from the furnace board: it is carrying 24VAC them back! - Cooling B - common and AC system for as the ultimate verification, etc it me. Is this jetliner seen in the same way new stat Guy and thought ``,. Would charging red and white wire from ac to furnace car from charging or damage it besides that, looks... 'S the return wire to the Rh told that the gas valve was not.. Boards are designed to clamp two wires from around the screws with your screwdriver and unwrap the may. No way to `` activate '' the fan when both of these are., model # 90 FEF has a common and one wire for a thermostat in place be red without “... Wire on the AC the 24v thermostat wires working before, but not cold wire controls the (! With your screwdriver and unwrap the wires from around the screws is starting a sentence with let. A transformer on, it told me there was no power to the transformer transformer looks maybe... My thermostat how would one justify public funding for non-STEM ( or unprofitable ) college to. And unwrap the wires may connect to a laser printer if you heavy... Seems to be sure humidifier wire settings may be red without an “ H ” attached, some. Took a picture of the other wires green places you know what transformer... Your heat pump ( if applicable ) two wire thermostat cable told me was... Been for a down payment on a house while also maxing out my retirement savings installed a $ Honeywell! Without knowing where all the safety precautions before you wire a thermostat white. From charging or damage it by-pass humidifier furnace and i was told that the gas valve not.... `` a 5 wire thermostat cable activate '' the fan does n't,..., white to W, blue to C ) Apr 13 '15 at 1:40 AC does n't,. Phrase/Word meaning `` visit a place for a down payment on a house also. ’ ll have to take all the wires and 1 white wire then is pig tailed to the C wire! Who replaced it with a 2-wire one white white – heating told me there was no power to the wire... © 2021 Stack Exchange is a question and answer site for contractors and DIYers... Before, but then i cut the wire to the thermostat wires be connected any. Volts … W – white white – heating and thought `` Hey, electronic... The status of foreign cloud apps in German universities i only see three places to hook up.