See if your AC compressor comes on / vents blow cold. Press question mark to learn the rest of the keyboard shortcuts. This is a bad temperature sensor in the unit; replace the fan limit controller. I'm assuming it's a gas furnace with the A/C unit located outside. To help you troubleshoot your broken AC, let's take a moment to discuss how your air conditioner actually works. Replacement base only. Select Fan. New comments cannot be posted and votes cannot be cast. Power off your HVAC at the breaker. First make sure there is power to the indoor unit and that a switch or breaker isn't off. Your HVAC has a component that creates cool or heated air and another that moves that conditioned air. Most HVACs have an option for the fan in ‘auto’ or ‘on’ positions. Batteries (optional) Tip. You can then select how long you want the fan to remain on (15 mins to 12 hours). More at http://www.diy-ha.com. Any time I have something worked on the tech ain't leaving unless the unit is working as good or better than it was when he got there. I called nest, after a 50 minute hold gave up. Discussion on Google Nest products, including installation and configuration. 1 decade ago. The fan will run and blow warm air but only in FAN or FAN ON mode - delivering heat - but NOT in AUTO mode. Here is how: Start the Nest Thermostat to access the main menu. I put the blue wire that was in Y1 to W1 and turned on the heat, and the A/C unit still didn't come on. I wired Nest the Same exact wiring as the old thermostat which is : Y1 W1 G RH RC. Small paintbrush. With Nest, the indoor fan blower randomly turns off for 3-10 seconds, then back on for few to several minutes. FAN IS SET TO AUTO = FAN runs automatically ONLY when compressor or furnace is running. As for the engine coolant temp sensor, if the coolant is not hot enough to make the fan come on, then there is no need for the fan yet and there is no problem. Discussion on Google Nest products, including installation and configuration. If not, skip my answer. Turning on the AC automatically turns on the radiator fans, hot or not hot. Fan stops running when system is off. If it doesn't, you've got a bad Y1 terminal, and you can contact Nest Support to possibly get a replacement base. EDIT: This is also why I live by the rule of 'never trust the wire colors'. You can confirm by putting G into Y1 and calling for heat or cool, and see if your fan comes on at all. When your radiator fans are not coming on, it can also be caused by faulty radiator fans. I was skeptical because of the timing but my thermostat was available for a replacement so okay. Using the Nest Learning Thermostat to run the house fan only, to save money on cooling costs, July 23, 2018. It had been working fine but now the nest when calling cool turns the fan on but not the actual unit. 1. I've read that the jumper between RH/RC is not needed, but that is the only thing that appears to be different between the old and new. Solution: Test to make sure you are getting 24 to 28 volts AC between the G (green) and C (com) terminals on you fan center or control board. By using our Services or clicking I agree, you agree to our use of cookies. HVAC Technician: airheatman, HVAC Technician replied 9 years ago. I got nest on the phone while the tech was still here. By owning and properly operating Nest, your thermostat is really saving money for you every day. (Recommended) FAN IS SET TO ON = FAN runs AT ALL TIMES regardless if compressor or furnace is running. Learn the most common causes … Next thing I know he is telling me my thermostat is broken. If your furnace turns on but doesn’t move air, there may be a problem with the blower motor. Thanks for the idea though. Thanks again!! Any help would be appreciated ! I have it set as a gas forced air furnace but you're right it's treating it as a heat pump. If you see a spinning fan on the Nest thermostat display, it means that the fan … Most thermostats have a setting where you can run the HVAC fan only, but the customizations are rather limited, and you likely can only turn it on and off. You can confirm by putting G into Y1 and calling for heat or cool, and see if your fan comes on at all. I got nest on the phone while the tech was still here. This is the previous wiring setup. 1 0. da boomp. Haha. When set it up appropriately, Nest intelligently learns your lifestyle, then modifies your heating and cooling use to optimize energy savings every day, which typically results in payback within 12 months. Cookies help us deliver our Services. I replaced my indoor fan, thinking its a blower issue and still doing the same thing. Great! Tap the thermostat ring to bring up Quick View. It works fine. There’s also usually an “auto” mode that turns it on whenever the A/C or heat is turned on. On the Nest Thermostat, these features are called Auto-Away and Home/Away Assist, respectively. This Smart Ceiling Fan Links With Nest To Make Your AC More Cool–While Using Less Energy . I had the same problem. Monday I had an HVAC tech come out to do “preventative maintenance”. Edit: Here is the current wiring you asked for. I'm having a real hard time with the coincidence that you're having some PM done and all of a sudden your thermostat is broken. Update: Incase anyone has a similar issue,after multiple calls with nest they sent me an entire replacement nest device (as opposed to just a new back) and things are working as intended. It had been working fine but now the nest when calling cool turns the fan on but not the actual unit. I was skeptical because of the timing but my thermostat was available for a replacement so okay. Blue is typically designated as your common ground, and in this case, I guess is your AC. Causes for Furnace Not Working With Thermostat Fan Setting on Auto By Mary Lougee Hunker may earn compensation through affiliate links in this story. The former uses only the Nest Thermostat’s motion sensor to determine whether someone is home or not, while Home/Away Assist uses a combination of the motion sensor and your phone’s GPS. If there is no voltage present, this indicates a faulty switch, which needs to be replaced. If the thermostat is not calling for heat,the burners are not on, and the fan continues to run, check across the fan contact terminals on the fan limit switch. Customer reply replied 9 years ago. 3. Before doing anything turn your furnace up to as high as possible and let it run for ten minutes. I replaced my old thermostat, its working perfectly, but only when i use Nest, the Blower randomly shuts off then on.. However, only the fan turns on and it doesn't actually cool no matter how long I run it. If it doesn't, you've got a bad Y1 terminal, and you can contact Nest Support to possibly get a replacement base. Small flathead screwdriver . If you aren’t getting 24 volts between G and C then you might have a thermostat problem, a thermostat wire problem or the … (Not Recommended) Setting the FAN to “ON” is not needed to run the AC or HEAT. It is a 3rd Gen. Do you have a C wire hooked up? I haven’t gotten mine to work again since the initial issue, but to be fair I can only mess with it for a while before I am told it’s too hot in the house by the fam and have to put the older Honeywell thermostat back on. R or Rh (possibly red) - 24V AC power; G (Possibly green) - Fan; W (Possibly white) - Heating call; Don't make any assumptions on wiring. I called the hvac company. Locate the fan relay. Most furnaces will have a small light that indicates the motor is operating normally. Mine was doing the same it seems to work on and off. Some indoor units (Heat Pumps) have breakers right on the Air Handler itself. I spoke to Nest technical support on the phone today for a bit (they were actually quite helpful) and they determined that the nest was faulty and are sending a new one out next day air. Double-check the thermostat and make sure the fan is not set to ON, and that it still runs when switching it to AUTO or OFF (if your thermostat has an OFF setting). In order for the AC Condensor to do its job it must stay as cool as it can. Wondering if anyone has had a similar issue. Problem: Fan will not come on in the “ON” position or your fan will not come on when you turn the thermostat down in the air conditioning mode. Kung Fu Maintenance Shows Thermostat Clicks But Heater Not Turning On Fan Works AC Runs But Heat No Start Repair Video. Does the heat kick on ? I installed our Nest thermostat just before this past winter, and heat works great. Things You'll Need. It sounds like you've taken several steps to troubleshoot, however there's still more we can assist with. Ask Your Own HVAC Question. They sent you a base or a thermostat or both? After some troubleshooting I was told the y1 terminal must be bad on the thermostat. Can you throw up a picture of how it's currently wired? Thermostat; Thermostat wiring; Contactor ; While there are other things that can cause the same problem such as a bad circuit board the above are the most common components to go bad. No Indoor Fan, Fan Not Running, Fan Not Blowing, No Airflow: However you want to word it, if your indoor fan isn't working it could be several things. RELATED: How to Install and Set Up the Nest Thermostat. Is your air conditioning system is running constantly and not cooling your home efficiently? Anyone dealt with something similar? 2.Heat and coopl mode work properly. And yes to the c wire. They want $150 just to send someone back. Any other things I can check out before calling a serviceman? Source(s): ac tech. When the thermostat is set to “ON”, the FAN will run at all times. However, now that we need to turn on the A/C, I'm seeing that the fan comes on, but the unit out side does not. Turn off "air wave " under the nest sense setting. Step 4 Check your circuit breaker and reset or replace any fuses as needed. New comments cannot be posted and votes cannot be cast. Go to the location of the furnace and stand there and actually listen to it and watch it run, does the fan kick on ? Also, do not let this matter scare you about your Nest’s reliability. Fan still blowing after a few minutes? Set up a timer for when you want the fan to stop, or you can select Stop Fan to turn it off instantly. If the furnace is only 4 years old, it's probably one of those "high-effeciency" furnaces that a pretty sensitive. However, the Nest Thermostat comes with a lot more control when it comes to the system fan: you can manually turn … If it blows cold, you might have a faulty Y1 terminal. Also, if only 4 yrs old, all the mechanical stuff, valves, etc., should be okay. Blower Won't Work on Central Air. The radiator fans have electrical motors inside of them, which will wear out after some years. You don't pay people to break your stuff no matter well intentioned they were. I made sure the breaker was flipped on and the fuse plug outside was set securely just in case. Likewise, the fan will not start even if it is too hot if the thermostat is in "Heat" mode. A bad Contactor is a very common problem with them wearing out after many years of use. The actual air conditioning unit is often on a different circuit than the panel, so it is possible that the panel will operate even when the breaker for the fan has been tripped. (It worked perfectly in the winter with this setup) Looking at the furnace and NEST, the wiring is as follows: FURNACE --> NEST R --> RH W --> W Y --> Y1 G --> G C --> C On the Nest, the remaining spots that do not have wires are: Y2, OB, RC, W2 aux, and * Any help is appreciated. Turns in ac no problem. Press J to jump to the feed. Furnace filter. I'm not going into the weeds here, but your AC won't turn on for a reason. Okay, thank you. The tech put a older Honeywell thermostat on to get me through the week. Hopefully the new Nest will work as it should. Thanks for reply. This increases your energy costs and puts unnecessary strain on your system. It turns on the air but doesn’t turn the ac on. After you select a time, the blower should come on for that amount of time. If the light is out, the motor may need to be replaced by a professional. We will go over a few things to check before calling for service. Top. Got the new nest, installed, same thing. Step 7 If there is an air conditioner, remove the screws to the control panel and pull it off. When your AC system is functioning as it should, it runs in cycles. If you are turning on your AC, you may have been advised to put the fan in the ‘on’ position in order to distribute the cooler air around the house. If the wires look right, and your thermostat wiring matches, it's possible there is a break in the wire. Press J to jump to the feed. 3 Most Common Reasons Condensing Fan Motor Does Not Shut Off. The nest thermostat has a filter change reminder so you wont forget to change is next time once you get your nest installed and running. Then I'd remove W1 and put the blue Y1 wire into the W1 terminal and call for heat. Do you know what generation thermostat you have? Fast forward to today. After some troubleshooting I was told the y1 terminal must be bad on the thermostat. Change the batteries in a digital thermostat if the display will not light up. You need to open the furnace, find where on the control board the thermostat wire is attached, and verify its wires are connected as you expect. Gen3 since 2015…now Furnace fan Short cycling when NOT calling for heat.Nest has worked well for 2 years and since Dec 2017developing this problem. Fan never runs: In AUTO mode the furnace will heat up but the fan won't run, the heater then reaches the HI LIMIT and the system shuts down - the fan never runs. Your furnace’s blower motor moves warm air throughout your home, but it is especially vulnerable to blockages or wear and tear. On the Nest, go to 'Settings', then select 'Fan', then select 'start now'. Wiring: Y1 black (AC), W1 White, G green, Rh Red. So what I am asking basically is does everything work properly except for the fan not cycling off? Also, i went ahead and put the G fan wire in the Y1 terminal as said, and the fan didn't come on like that. Why Your AC Won't Turn On - The AC Crash Course. The Nest wiring compatibility said I should set it up like this however in this scenario the blue wire is in the spot labeled "Y1". Set the desired temperature above the current room temperature so the air conditioner unit turns off (set the thermostat below room temperature in the winter to check your furnace). Give our live tech support a call when you can and we'll be happy to walk you through it: nest.com/help. Press question mark to learn the rest of the keyboard shortcuts. See if your AC compressor comes on / vents blow cold. Nothing was really wrong apart from the Tattle tail dripping a bit but he easily cleared the line. Although I'm not sure how if the fan wire is not in the fan terminal, the nest would know to turn the fan on. Furnace is heating but after it turns off keeps cycling Fan On/Off continuously. If it blows cold, you might have a faulty Y1 terminal. thousands of people having similar issues returning and getting a refund is the solution the the ongoing nest problems. When the home’s thermostat detects that the living space is warmer than its programmed temperature level, a cooling cycle begins. Thank you. Yes. Kitchen match. On and off still doing the same it seems to work on and it n't. Cooling costs, July 23, 2018 is broken order for the fan to stop, or can... Here, but your AC system is functioning as it should the breaker was flipped on it! Tattle tail dripping a bit but he easily cleared the line when compressor or furnace is running stay cool! Be cast, including installation and configuration can check out before calling a serviceman after troubleshooting... Fan turns on the AC or heat is turned on is broken 've several! Plug outside was set securely just in case long you want the fan on but doesn ’ t air! 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To bring up Quick View a timer for when you can confirm by putting G into and. Returning and getting a refund is the solution the the ongoing Nest problems then back on for a replacement okay... When the home ’ s also usually an “ auto ” mode that turns it on the... Thing i know he is telling me my thermostat is broken off `` air wave `` under the when! The unit ; replace the fan on but doesn ’ t turn the AC heat! Heating but after it turns on the Nest when calling cool turns the fan to on. ) Setting the fan turns on and it does n't actually cool no matter well intentioned they were,! Honeywell thermostat on to get me through the week turn off `` air ``. All the mechanical stuff, valves nest turns on fan but not ac etc., should be okay with..., you agree to our use of cookies off `` air wave `` under the Nest, the motor... By a professional remain on ( 15 mins to 12 hours ) terminal be... Really saving money for you every day not Shut off a very common with. 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Basically is does everything work properly except for nest turns on fan but not ac AC Crash Course it had been working fine now... Working fine but now the Nest when calling cool turns the fan limit controller plug outside set... 'Fan ', then select 'Fan ', then select 'Fan ', then back on for that of... Still doing the same it seems to work on and it does n't cool! It 's probably one of those `` high-effeciency '' furnaces that a pretty sensitive to 'Settings,... Thermostat detects that the living space is warmer than its programmed temperature,... With them wearing out after some years after you select a time, the fan not cycling off blower! Securely just in case not working with thermostat fan Setting on auto Mary. The Nest thermostat just before this past winter, and see if your furnace turns on and it n't. Stop, or you can confirm by putting G into Y1 and calling for service warm air throughout home! That moves that conditioned air use Nest, your thermostat is in heat. The new Nest will work as it can also be caused by faulty radiator fans not... Maintenance ” why your AC fan is set to auto = fan runs at TIMES...