Blower Fan Motor Won't Shut off!- STEP by STEP Troubleshooting!

[@acservicetechchannel]

Support and Tool List- www.amazon.com/shop/acservicetech Support- www.patreon.com/acservicetech For those that are looking for the tools used in the videos: (Linked Below) Here is the Link for the newer UEI DL479 Multimeter with temp sensor- amzn.to/2jtsUbJ Here is the Link for the newer UEI DL 469 Multimeter- amzn.to/2jw4ePJ Here is a link to the UEI DL389 Multimeter used in this video- amzn.to/2av8s3q Supco Mag1YL magnet jumper wires- amzn.to/2oiDaZ8 Here is a link to the 24v Thermostat used in the video- amzn.to/2bDeUak Pair of Alligator clips- amzn.to/2nDnQ67 Here is the link to the Fieldpiece ST4 Dual Temp Meter- amzn.to/2wc1ME3 Here is a link to a magnet used for holding the door switch down- amzn.to/2gdXd89 Other tool links can be found in the video description section. ACSERVICETECH is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com. Check out other videos on the HVACR topics of interest at- kzbin.info/door/OZR-1IqsAer9wzlvFgb4mAplaylists?view_as=public

[@jrod7017]

I have an older unit with a mercury-type thermostat. It looks different. What should I check?

[@MouthPounder74012]

Nice ad 👏 👍 👌 lol

[@Xhoven]

Hey, thank you so much for this video. Long story short, furnace stopped working a week ago. A technician quoted me over $1300 for the repair (new control board and transformer). I bought the parts online and put them in but then my blower motor was continuously running. Was fretting because I didn't know if the new control board was bad. Watching your video helped me understand exactly how the wiring works and how to troubleshoot it. I figured out my thermostat needed replacing well. All in all I saved over $900 by replacing everything myself and your videos made sure I didn't have to call another technician out for another $90 diagnosis.

[@acservicetechchannel]

Thanks Xhoven!

[@luanpham7469]

Xhoven, I wonder why your furnace could be failed all of these at the same time ??

[@jhrace2]

You helped me identify that my problem was a faulty thermostat. Thanks so much for saving me a repair call from my local HVAC guy!

[@Locbui1989]

great video for newer Furnace, but the older ones come with relays and fan switch that could also cause a constant running BM

[@traviswilliams2272]

This is one of the most helpful and informative channels on KZbin. Thank you sir

[@acservicetechchannel]

Thanks Travis!

[@Deicide1966]

Before you go through all this, check the limit switches. A simple bad limit switch will also cause your blower to keep running.

[@HsingSun]

It sounds a good idea. I have tried to order two of them, but the price is high. I may order them now.

[@spartan5106]

I had to watch it a couple of times to understand but it was very informative.

[@richardmurphy9614]

Great video. One thing also to check is on the Honeywell thermostats they have those pins from the thermostat to the base plate when customers change the batteries most of the time they bend those pins closing the circuit

[@acservicetechchannel]

Absolutely, Great Comment!

[@Hvacmania]

Richard Murphy wow always learning in this trade

[@tlitchford]

Thank you for this video. Following your troubleshooting steps, I found that the board on the wall plate of my thermostat was fried. My blower was stuck, and I had checked the wiring and experimentally tapped the relay and thought I might need to call a tech. Thanks!

[@diyerintn833]

Great video, extremely informative. Before you do anything, check the thermostat wiring to your unit for damage from mice or other rodents. If the thermostat line is not installed in conduit, then this is a quick starting place where you might find your trouble, particularly is the problem is sporadic. In my case, I found there was a wiring problem when I checked the voltage between red and common at the thermostat and at the unit and found they were different. When I chased the wiring, I found that something had chewed up the insulation on the wiring underneath the unit. So, I repaired it and ran it inside conduit.

[@acservicetechchannel]

I have found mice chewing thermostat wires in mobile homes usually but not so much in houses, thanks and glad you found your problem!

[@baffled3111]

My units 7 YO fan has been running continuously for a couple days now. I viewed your video and started troubleshooting by separating the thermostat face from the wall plate - fan continued to run. Since my unit is in the attic and, even during this time of year in Florida, it's very hot and uncomfortable up there, I decided to try something else prior to going up there and going through your other troubleshooting steps. I have an AC and a Heat circuit in my breaker panel. With the fan still running and fan and system both set on Auto, I went through the following steps: 1. Turned AC breaker off - fan continued to run and thermostat remained illuminated. 2. Turned Heat breaker off (AC breaker still off) - fan stopped and thermostat "went dark". 3.Turned AC breaker on (Heat breaker still off) - fan still off and thermostat still dark. 4. Turned Heat breaker on - thermostat was illuminated and fan was Not Running! It's been about 4-5 hours now and the fan has remained off, except during two ventilation cycles, after each of which the fan turned off automatically. Will you please offer an explanation for my apparent good luck, and also let me know if the sequence I went through could possibly have solved the underlying problem, or if it was somehow just a lucky "bandaid fix" and I'll soon be faced with another continuous fan issue? Thank You!

[@newlife5896]

Did you ever fix it? My air handler for my system is doing the same thing. Only shuts off when i flip the breaker. Thermostat is off and the blower still blows

[@4underpar]

EXCELLENT! Thank you. Do you have close up pix of where you touched the probes? Hard to see in the video.

[@acservicetechchannel]

Roark, I don't have any close ups of this particular video but I do have close ups of troubleshooting the thermostat and blower motor. Here is bypassing and testing of the thermostat and wiring. --- kzbin.info/www/bejne/gGrFqX-mf9WFhKc&list=PLxnHR5_D2ojzDfU1IjPpzdhi_mUGe3F7W&index=13 ------- Here is testing of a furnace blower motor -- kzbin.info/www/bejne/nJ3FhqeCgsqGhbM&list=PLxnHR5_D2ojyDrxCT9MIttGW4wxOZ3n-7&index=9

[@kyky7kyle7]

When you took off the green fan wire and tested the 2 locations what where those 2 locations?? Also fan still runs with green disconnected from the board

[@jpcalo8]

Excellent video. In my case the control board was bad.

[@acservicetechchannel]

Thanks jpcalo8!

[@clint1285]

​@AC Service Tech LLC my fan won't turn off either. The red light on my board is always on and the error code says " continuous red light , replace board"

[@betoamaya7248]

Love the vids thank you it helps me out fresh out of HVAC school always learning something

[@acservicetechchannel]

Thanks Beto! Glad tom help you on your journey!

[@commonsense3673]

@@acservicetechchannel this goes to show how much you need to follow the instructions in the school training and apply all the knowledge that you have

[@adiletbai]

Thanks for video My furnace blower stays on only with AC mode. On Heat its fine and turn in and off as supposed to be. AC reaches set temp and after tstat clicks shuts off but blower keeps on. AC works fine! I have replaced tstat with thoughts that it is causing but nope didn’t help. Mentioned When i pull tstat the blower shuts off.

[@acservicetechchannel]

If pulling the tstat cover shuts the fan then it definitely has something to do the the tstat, otherwise sounds like a fan relay, thanks!

[@JonEhBee]

If you have a simple 3 button thermostat, you probably want to verify you have gone to the "fan" function and changed the setting to "auto" there, then go to heat or cool as needed, before you dig into your ac components.

[@danielpowell8546]

brilliant! thank you for going through step by step troubleshooting! I feel much better prepared to tackle my AC problem now!

[@cookiesnation5321]

My a.c. unit is an old model which was installed in the garage way back in the 80's so hopefully I can check it without any issues.

[@acservicetechchannel]

Thanks

[@marine0371]

Been out the Biz, but still the same. TY

[@giovannireyes8398]

I saw the entire video, and you mentioned at the end that changing the wires will solve the problem. Was it solved, or did you change the board to solve the problem?

[@reggaejja]

Very nice troubleshooting!

[@acservicetechchannel]

Thank you very much!

[@robertpalmatier2699]

Sell them a unit Craig! 😁

[@donnierobertson3088]

Great job again like always

[@acservicetechchannel]

Thanks a lot Donnie!

[@johnmiller102]

Very well done. Great explanation on the control side of the hvac unit.

[@acservicetechchannel]

Thanks John!

[@Tj146164]

Great information, thanks for the video.

[@acservicetechchannel]

Thanks No_Mercy!

[@keithshreve6736]

Excellent Video and training ! Thank you for sharing your knowledge ! Done very well !

[@acservicetechchannel]

Thanks Keith!

[@douglasmccoy2571]

I’m really REALLY surprised that u don’t got to may subscribers....very helpful and detailing steps

[@acservicetechchannel]

Thanks Douglas!

[@jeffmattero8500]

Rather than exchanging the brown for the green wire, why not test for continuity between the green and red wires at the furnace? Wouldn't that prove a connection between the two?

[@AKatawazi2]

So what is you completely replace the thermostat and terminal block but taking off the thermostat still shuts off the fan? I’ve tried 3 thermostats and they all do the same thing with two totally new terminal blocks.

[@acservicetechchannel]

That is what it is supposed to do. What is the problem?

[@AKatawazi2]

AC Service Tech LLC Fan still runs all the time even though I replaced thermostat with two different units. When I take off the thermostat it shuts off the fan, otherwise it runs all the time. I also replaced the terminal block. I am baffled at this point, thanks for the help! Unit is a Rudd 4 Ton heat pump and evap coils.

[@actechformallyyomama746]

Their is a short feeding off the thermostat. Have you gone through the set up of the stat for gas or electric heat? It might be a switch or jumper on the new stat. It is not the stat. You could have it wired incorrectly.

[@joshdurniok3225]

Is it okay for a brand new motor to have up and down play in shaft? I had a blower motor and the shaft was moving up and down direct drive psc motor. I got a new one and that one also had up and down play on the shaft so I opened another one on my truck and that one doesn't have any play. I would think up and down play on any shaft isn't a good thing I know the motor can run like that, but for the longevity of the motor and for the customer I've seen bearing drop before and makes the motor fail sooner

[@shentelleallen9716]

Really nice video and very informative...question what should I check if I changed the contactor and now the power on the thermostat won't come back on?

[@shentelleallen9716]

@Blue Khalifa I will check that tomorrow and let you know if it worked, i just never encountered that before. But there is a light that is also a part of that circuit that this circuit breaker also powers and the light works fine.

[@shentelleallen9716]

and also i still have the same issue with my fan blower not turning off unless i turn the circuit breaker off

[@SombraLocs]

Another great video!

[@acservicetechchannel]

Thanks, I always enjoy your comments!

[@jewdali1]

A picture is worth a thousand words

[@kenwilla5051]

So we currently have a problem with the a/c internal blower running non stop even after the desired temperature has been reached. Our original honeywell thermostat (similar to RTH6580WF without WiFi) failed to turn off the blower even when setting it to off, so I tried replacing with another honeywell thermostat that has a manual off switch and now the unit turns on and off, but when it's on cool, the blower still runs continuously even when temp is reached. In fact, last night it had dropped 1 degree below the set temp and was still running, so I turned it off to keep it from running all day. I think I'll try some of the steps in your video, but was wondering if you could provide any additional info related to our problem. I'd like to avoid another pricey service call if I can help it. We recently had our unit recharged (told we may have a slow leak, but not yet confirmed). We were also told a few days ago that our heat strip is bad (was mixing hot air with cool and taking a long time to cool the house - also spiking our electric bill), so they temporarily disconnected it until we can fix it.

[@kevincarel735]

I appreciate your videos and they are done up very well.If I could ask, do you think we should troubleshoot these things from the inside out, rather the outside in? Meaning, if there's an issue with the blower, we start from the blower and work towards the t-stat, rather than start at the tstat? Here's why. I, too, had looked at the tstat first, then tblock, then wiring, then the board itself. Through eliminating all of the aforementioned parts, I ultimately found 0V on the G terminal of the board while the fan was running....so I, too thought it was the board. Bought the board and swapped and same problem persists. So I still do not have a solution to my problem, but here are some remaining questions: I'm seeing about 5 wires coming out of the motor with 2 capped off. So I'm assuming it's a 3 speed motor (I honestly don't know). nonetheless there has to be a constant power to that motor and I'm curious if there's a possibility there's an issue with the wiring inside the motor that would put it on constant run? Clearly one of the wires has to go to the relay so perhaps the relay is stuck on? So obviously, it is something between the motor and the board (with board and low volt enables and tstat eliminated).If this is not a comprehensive diagnosis and mainly focused on enables, I apologize. This one has me puzzled and I'm about to pull the whole blower assembly out to start checking wiring. but once again, I love the video. Very nice! :)

[@acservicetechchannel]

Thanks for the questions! So the reason I approach the service from the start to the finish is just so everyone understands the full operation and is the same way I teach at school. I do however, like you said, just go right for the problem and work backwards out but I can't work backwards out unless I know frontwards. That is all. Is this motor a psc motor with capacitor, a ecm x13, or a variable speed ecm 2.0, 2.3, 2.5, 2.7, or 3.0? In this playlist, I have variable speed, psc 120v and psc 240v, and x13 troubleshooting and motor details.----------kzbin.info/aero/PLxnHR5_D2ojyDrxCT9MIttGW4wxOZ3n-7

[@WorldCommander]

Thanks to your instructions, I was able rule out the thermostat and wiring and find it was a relay on the circuit board. Where can I find a replacement board for a thirty year old system?!

[@acservicetechchannel]

You would need to contact a local distributor of that brand of equipment and they can order one based on the model and serial number, thanks!

[@WorldCommander]

@@acservicetechchannel Thanks for the reply. I did check with local, unfortunately no parts are available. Obsolete. So, time to upgrade to a new system. Need a video on Trane vs Carrier vs Lennox vs ???

[@DjTechoBeatz]

Nice Thanks!

[@acservicetechchannel]

Thanks!

[@aarongray503]

Thank you for this video! My blower motor stays on unless I shut it off at main shut off or pull the face plate off. It wouldn't shut off if I turned it to off. I'm going to go buy another therm. My thermostat is only a little over a year old.

[@sportyfareal3]

Did that work?

[@Pretzel114]

Great video ACSERVICETECH! Those terminal blocks on the t-stat, can you replace them or do you need a new base plate? Thanks.

[@acservicetechchannel]

You need a new base plate. Thanks

[@Pretzel114]

Thanks for the reply I appreciate it.

[@lenbodnar205]

I have a 2012 5th wheel with furnace issue....My thermostat is set at 68 degrees F and the furnace operates fine But the furnace won't shut off...I have a 5 button thermostat which has been replaced 3 days ago but still not working. My dual therm thermostat is very pricey and all wires are connected proper.We had a service man here But he knew and did nothing.So we have too find a geek to solve our problem. P.S we had the furnace working fine yesterday morning from 6:30-2 pm without an issue, then it started again to malfunction ...need some answers as needed this furnace to heat the nights as it dips down to 2 degrees. thks

[@acservicetechchannel]

Hey Len sorry to hear that. Without being in front of the furnace and not knowing the type I would not know. The channel is set up for techs. It sounds like the thermostat is not the problem but without reading voltages one would not know the issue. My only recommendation is to have a tech out from a reputable dealership that sells them. Thanks

[@starsofsirius559]

2 things to check first which I didn't even think or realize, which you should do before even watching this video. 1.Check to see if you have an air exchange switch somewhere upstairs. Turn it off. It's like a light switch 2. Bathroom fan! My house has it so it exchanges the air in the house if it's on. My roommate had her bathroom fan on and I never even considered it.

[@jimbola77]

confusing partner but I wil watch it and take some note's that's how it work's for me but super explanation and great video's all of them thank you for sharing!!!!!

[@acservicetechchannel]

Maybe revisit the "thermostat wiring" video first, then "troubleshooting blower motor of a furnace and ac" and that will set you up for this one. Thanks

[@mahesha5886]

Hi my carrier package unit not cut off at the same time by thermostat remote showing 50°c room temperature so I was changed new therkostat Remote also the same problem came how can I troubleshoot

[@tommyhoule4025]

Question ! My electric furnance blowe is running without the (G) connect inside the motor board , and don't strop when we as the thermostat to stop. One others thing I got is , half of Element is working ( 2 stage ) .... and ,so I decided to BYpass one sequencer to see if it was this. If I bypass 1x sequences, all element work except 2 .... W1 and W2 are bypass. What is the your idea ? Furnace is 5 years old.

[@acservicetechchannel]

That would be considered an air handler equipped with electric resistance. A furnace is typically a combustion fired appliance. It sounds like a safety sensor is tripped which allows the blower to run all the time. It sounds like that or one of the relays is stuck closed. That is high amperage in there so I may recommend a tech to come for safety, thanks Tommy!

[@tommyhoule4025]

@@acservicetechchannel do you have a phone number?

[@tommyhoule4025]

Ok.. here my big problem. I will try to do my best in english. When I ask my thermostat to get heating, the fan blower start witch is normal. But blower never stop... then I open the planum a bit and saw that the element inside the furnace work only on 1 stage, but should work on 2 stage because ny w1 and w2 is bypass at all time. Then first this , i go look the limit stiwtch if one stuck open and Yes, there is one open. I bypass the wire direct without the first limit switch (because we have 2) and look again inside the furnace. I got more element working but not all? How its possible.... spring broke(element)..? And the fan blower.. still got the problem... i test the thermostat wire.... i disconect the G from the panal board... and still the blower start without the G ask for it... make sense if its on safe mode ( limit stwich open) but.. the limit switch is bypass now and work.... look like 2 problem Any help?

[@acservicetechchannel]

It is possible you wouldn't need power on g if you were calling on emergency heat if there was a board. G is normally powered but the board may see that heat is being powered. With the power off and the element that is not working disconnected, it should have a resistance reading in ohms. If it reads 0.L then that element is broken. I would not run that without the second limit working. You need both in there working properly to cut off the power before a problem occurs. You should order that right away. Have you seen the video I did on "electric resistance acservicetech"

[@tommyhoule4025]

@@acservicetechchannel I changed both limit switch , anf still got the second stage element not working and fan dont stop.... maybe the relay? How relay work?... im realy confused.. because if i jump the 2 wires ( limit switch ) straight(bypass) with pin the second stage start working.. but not if i pluged the new limit switch.

[@sergiobullitt4509]

great video

[@acservicetechchannel]

Thank you very much!

[@jimmyung3212]

Great detail thanks!!!

[@acservicetechchannel]

Thanks again!

[@acservicedaytona386portora3]

again a great video

[@acservicetechchannel]

Thanks Robert!

[@jens4016]

Great video. One question how long after you take the thermostat off should the fan turn off? Immediately or does it take a few minutes? Thank you

[@acservicetechchannel]

Usually less than 30 seconds

[@chandarasena]

Thank you very much for this great video. It give me a lot more lesson I did not know before.

[@acservicetechchannel]

Thanks chandarasena!

[@tonyran1611]

Great help thanks

[@acservicetechchannel]

Thanks Tony!

[@benspeakman2623]

what if it's not the t stat or wire? bad board? or you briefly mentioned a limit switch but didnt really touch on that

[@MrDmadness]

The blower will continue to run if the funrnace has had a high limit temperatur switch trip, the blower keeps running to attmept to cool the furnace, this is usually evident by a manual reset imit switch ( look for a limit with a small red button ) but often times is an auto resetting limit. You would need to check limit switches and see if there is a differential potential on both sides of the swith, if the circuit is open then it means the limit has tripped. If the high limit has tripped then you need to figure out why, often this is caused simply by a dirt filter, in many cases also expensive 3-m type filters cause this to happen as they limit the airflow too much. hope this helps. :)

[@RineboBohead]

Thank you!!!

[@acservicetechchannel]

Thanks Rinebo0011!

[@Whitbug68]

Okay so my air won't turn off at the thermostats, I have 2 and 1 unit. He came yesterday to fix a no cooling problem. It ended up being a stuck zone damper in the attic. I woke up to mid 60's, set at 74 and won't turn off at the thermostats. Have to turn them off at the electrical panel. What is wrong do you think?

[@acservicetechchannel]

Do you have 24v from y to c on the board when the tstat is not calling for cooling?

[@TheSincere20000]

7:18 where did you test for 120 volts

[@acservicetechchannel]

L2 common and the hot output from the control board relay, thanks

[@DWAYNE2ism]

good video

[@acservicetechchannel]

Thnaks Dwayne Doxilly!

[@hsulli5800]

thanks for sharing

[@acservicetechchannel]

No Problem, thanks!

[@sajidrafique375]

Can sometimes relays get stuck and remain on even without 24VAC ? At my thermostat terminal , I dont see any 24VAC (probably a blown fuse) but the fan is ON and wont shut off .

[@acservicetechchannel]

Yes relays can get stuck and the contacts burnt together. That is a possibility, thanks!

[@GetRealwithJesus]

Very thoroughl anyway can you jus come over an fix this I dont have a voltage meter. Ty

[@acservicetechchannel]

You should ask around and work with referrals from neighbors or friends for the correct company to select, thanks!

[@SouthernFoodJunkie]

I have a carrier heat pump and the blower motor will not shut off. I at one point I could pull the face of the thermostat off and the motor would then shut off but now it will not do that. It was making a clicking noise outside. I had a HVAC tech that mainly works on industrial stuff (he is a neighbor and he was just helping me out) change out a relay that was stuck then the motor seized up and we changed that out too. Any idea?

[@acservicetechchannel]

You would need to read if there was 24v from g to c on the control board when the tstat was not calling for fan first, thanks

[@SouthernFoodJunkie]

acservicetech Thanks

[@lashesone]

Hello I have a question I had the AC company replace the heat coil and after it was replaced I noticed that once the temperature is reached on the thermostat the vents stop blowing air and the fan outside runs constantly I can shut the unit off and it turns off but it sucks because I can leave it on and I need the heater.

[@acservicetechchannel]

It is likely that they wired something incorrectly on the low voltage because the fan should always be on in the indoor unit if the outdoor unit is running, thanks and sorry to hear that!

[@franktrujillo6879]

Blower works for AC not for heat

[@dapperdon7212]

Still keeping up with the videos throughout my career. Always watch 30min a day. Is there any way you can do a video explaining schematic symbols. Probably most difficult for me. Especially on trane equipment

[@acservicetechchannel]

I will keep that in mind Dapper Don. Thanks for letting me know what you would like to see! Thats the way to go and learn, 30 minutes a day!

[@mijemumijemu4466]

If I have my thermostat wires on wire nuts outside the furnace can i disconnect the green there instead of from the board, will that give the same results?

[@acservicetechchannel]

Yes except it won't take out the possibility of the wires touching each other somewhere, thanks!

[@lkheatingcoolinginc.9803]

Thank you very much for your help!!!!!!!!!

[@acservicetechchannel]

Thanks Leonid!

[@traderflorstock9497]

Hello there. I have a York system and my problem is the opposite. The blower motor shuts off and my condenser AC unit outside keeps running and freezes my lines. Can you point me to the right direction? Thanks.

[@acservicetechchannel]

Do you have a fan limit control , fan relay, or control board controlling the blower motor? Do you have a shaded pole, psc, x-13, or variable speed motor? That would help in determining the problem. Also does the outdoor unit continue to run after the thermostat has reached its set temp?

[@traderflorstock9497]

AC Service Tech LLC control board ; unknown on the motor type. Blower turns off before reaching temp. Sometimes at temp.

[@purrungas2012]

thank you for your video really helps, question: my blower motor does not remain on when the heating shuts down, not even a second, can you please give me a pointer, thanks

[@acservicetechchannel]

Do you have a control board, electronic fan timer or, 24v sequencer, or fan limit control? If it looks like this then you have a board. You may have dip switches that you can set for the blower off delay. You might want to set it for 60 or 90 seconds unless your furnace is a downflow in which you may want to set it to 120 sec. Thanks

[@purrungas2012]

this is an old G.E. package unit, which has a fan/limit control switch which I just replaced, no board

[@deerphoria4314]

I have a Goodman furnace Model GMPN100-4. My blower never shuts off even if the thermostat is set to Off/Auto. The only way to shut it off is to pull the plug on the furnace. There was continuity on the hot surface igniter, but no continuity on the limit switch. Is the bad limit switch the problem?

[@acservicetechchannel]

If it is a limit switch for testing purposes only, you could jump it out temporarily and then turn the power back on to see if the fan does not run. Just make sure not to leave the jumper there as no safety limit should be jumped for normal operation. Some furnaces are wired in the way you are describing. Also check for 24v from g to c on the board. You could turn the power off and take the therm wires off the board and turn the power back on to see if the problem persists. Let me know what you find or any other questions. Thanks

[@dh889]

Hi, why does my furnace blower fan stop and rapidly restart intermittently during normal furnace flame operation? You can here the fan power down, then rapidly power back up again 3 or 4 times in 15seconds, then stay on awhile till it cycles down to cool. Would u have an idea?

[@acservicetechchannel]

Is it an x13, variable speed, psc, or shaded pole blower motor? If it has a capacitor, it would be a psc, look up blower motor identification acservicetech for a video, thanks

[@3beltwesty]

On a 3 decade old 120 volt Carrier system here the relays can stick after they are 25 years old. The fan keeps running after the call for AC or Heat has stopped. One can tap on the relay and it will unstick as a sign that one needs a new board, or the old relay contacts cleaned. My place has two airhandlers and thus 2 boards. This video link below is where I tap on a faulty one to unstick it. This is not a repair, but a ancient troubleshoot method. You have to be carefull you do not hit any live wires. The real odd thing is the unit will usually only stick every few months when it first happens and it gets worse slowy. ie it might happen a few times a year at first. But when one opens up the access panels the relay may go "unstuck" since one is bumping around removing the panel! and thus with the power off one really is baffled since the problem "went away". Thus a weird intermittent issue can drive one nuts until it is understood. kzbin.info/www/bejne/ZnjFq5KHrtaDpNk

[@acservicetechchannel]

That would mean that the contacts on the relay are actually slightly melted/burnt together. They get rough instead of smooth on their surfaces and the smaller parts that the amperage is going over remelts onto the other contact again. I see this on old open contactors and other relays quite a bit. Thanks for your comment!

[@ToddOutdoor]

I have the Honeywell 5 N 1 heat pump. Blower motor is blowing constantly. I did shut off the power disconnected the thermostat. The fan did not come back on until I reconnected the thermostat. I'm thinking the thermostat is bad? Your expert opinion please.

[@acservicetechchannel]

Without seeing voltage readings I would not be certain but it sounds like you are right that the tstat may be bad, thanks

[@ToddOutdoor]

@@acservicetechchannel I done a reset on the stat and it has worked great until a few minutes ago. Now the fan isnt shutting off but the heat does.

[@uneCENT]

Any idea how to handle an issue like this where my AC/Fan run constantly? I remove my thermostat and after ~1 min it turns off. A new Thermostat didnt fix the issue. using a multi meter I see 24v on the Y, but from the outside unit not the thermostat. If I pull the Y from the thermostat, I still see the 24v on the Y from the outside, but the fan then stops.

[@bennydayao2619]

great video, my blower run around 5 seconds then stop then run 1sec. then stop repeatedly, is the motor is bad?

[@acservicetechchannel]

Is it a variable, ecm, psc, or shaded pole motor? Thanks

[@moeboom2519]

Hi acservicetech! great video. I am an installer and I saw one time that a blower would not turn off after customer set it to heating before we hooked up the gas. The unit locked out and kept the blower on even after turning unit off from t stat. we had to pull high voltage plug for blower to come off. is this normal? Did the blower get locked in from the board because no flame was sensed as a safety? Also, I have had customers tell me to lower their fan speed but no one has ever showed me!! do you just switch the black lead on the board with whatever speed you want it to be? like switch the black with the red or blue. etc. Thanks!

[@acservicetechchannel]

It is likely that a fault set the blower motor to run continuously depending on the brand. It was in lockout likely. If you lower the fan speed for heating mode then you still should check to make sure that the temp diff between the return and supply is still only 50 degrees and not hotter so the plenum heat sensor doesn't go off. Likewise in cooling you should check the charge again to make sure that you still have enough air going across the coil and still have some superheat. Check this troubleshooting blower motor playlist out.--- kzbin.info/aero/PLxnHR5_D2ojyDrxCT9MIttGW4wxOZ3n-7 ---- and especially blower motor fan speeds and testing --- kzbin.info/www/bejne/mYnIoYRogax4gpY&index=10&list=PLxnHR5_D2ojyDrxCT9MIttGW4wxOZ3n-7

[@emmanuelsilva4753]

So i disconnected all the t stat wires that goes directly to the control board and turn on the door switch. The blower motor turns on and the Igniter turns on but not the gas valve does that mean the control board is bad?

[@acservicetechchannel]

Make sure that you have 24v to the gas valve from the board at that point when the hsi is glowing, 5-7inch wc upstream of the gas valve if nat gas or 11-13" wc upstream if Lp. You should have an output gas pressure as denoted on the rating plate of the furnace or the new Lp conversion rating plate, thanks

[@acservicetechchannel]

You would need to test to see if you have 24v going to the gas valve when this is happening and then if you do, check the inlet and outlet gas pressure with a digital water column manometer, thanks

[@jimbola77]

sweet video!!!!!

[@acservicetechchannel]

Thank you!

[@geojor]

thanks for this ...

[@acservicetechchannel]

Thanks pei broker!

[@CesarGarcia-db8gn]

thank you very much that was very very helpful

[@acservicetechchannel]

Glad to help!

[@whitesheatingairappliancer7101]

have a 1985 carrier replaced main board, blower continues to run. removed all low voltage wires, blower continues to run. check safety stats all good. found second board for inducer and has valve. I need to check.

[@acservicetechchannel]

What are the m#'s of the 2 boards and or the furnace?

[@IshockO]

Good video

[@acservicetechchannel]

Thank you!

[@Hvacmania]

So why did you disconnect that 120v wire again ?

[@acservicetechchannel]

It may have been during the resistance check of the blower motor or the testing of the capacitor or just for safety between moving the multimeter, thanks

[@Hvacmania]

AC Service Tech LLC wish i had money to support channel . your videos contain great value !

[@acservicetechchannel]

Glad to help Gerardo!

[@firdauskhush8158]

I got my furnace working normal at start, till it reaches the set temperature, then starts blowing cool air, have a brand new board on, thermostat is clicking when I change the set point, same problem with new thermostat. checked thermostat wire, no shorts, blower fan keeps running at all times. had thermostat on off blower fan still runs, where the problem is and what u suggest I should do, new filter, haven't cleaned sensor yet, will tomorrow. any suggestions would help and appreciate your help.

[@acservicetechchannel]

What do you mean working till it reaches set temp? Does it fire and provide heat and then blower continues to stay on? Do you have a fan limit control or board that powers the blower motor? When the blower is running after you are to the correct temp in the house, do you have 24v from g to c or w to c or y to c?

[@firdauskhush8158]

acservicetech yes, it blows heat till it reaches the set temperature on thermostat, then starts blowing cool air. after a bit it goes back to warm air.

[@principeazteca2000]

nice videos....thanks sir..

[@acservicetechchannel]

Thank you kesil!

[@rasrastaman5712]

Excellent info. For me , a little too much info in 1 vid😂😂😂 plus I couldn’t see where he was touching... I guess there’re letters written on them? Thank you tho.

[@acservicetechchannel]

Thanks

[@jameswasher3938]

An old oil furnace I worked on years ago was showing a similar symptom. It turned out to be an overtemp sensor that was keeping the blower running waiting for the heat exchanger to cool down (which was never going to happen). I just checked the schematic for my current (80%) gas furnace, and I see no such sensor. Are such sensors no longer in use?

[@acservicetechchannel]

The fan limit control you are referring to is only really used on some oil burner furnaces now. The control board now tells when to turn the fan on for newer units. I did a video on Fan Limit Controls if you were interested! Thanks for your Comment!

[@fconde6157]

Why does my blower keeps making a humming sound when I turn off the AC? It will not stop until I unplug it. Thanks

[@popsncracks9108]

I have some problem my furnace can keep running but heat pump turns off. I replaced control panel but fan still keep running. I turned power off the removed thermostat cover and turned power back on and furnace still running. Is that mean thermostat good? What is problem ll be? Pls help thank you.

[@acservicetechchannel]

That does mean that the thermostat is good if the same thing happens when the thermostat face is off. What happens when you turn the power off and disconnect the w wire off of the control board and then turn the power back on. If nothing happens then the problem is in that thermostat wire.

[@popsncracks9108]

acservicetech do you mean W wire goes to termostat? There is no W wire going to control panel. Btw I changed termostat and control board. But still have same problem.

[@popsncracks9108]

acservicetech do you mean W ( white wire ) going control panel, yes I unplug it then turned power back on, and fan still on

[@Crifstar]

How do I get the fan to run continuously when I select fan on?

[@acservicetechchannel]

With the power off, a thermostat wire must be run from your g terminal in your tstat to the indoor unit g terminal. Then turn power back on and select fan on, on the thermostat, thanks

[@JulesBartow]

I'm so confused. First I thought AC meant Air Conditioning. Then I found out AC means Alternating Current, but its referenced to voltage. If there is an open circuit, there will be voltage, and no current per Ohm's Law. Does the voltage still alternate if there is no current to alternate? Are you setting your UEi DL389G2 Phoenix PRO+ True Root Mean Squared RMS Digital Clamp Meter to AC when you're taking HVAC voltage measurements? My Snap-On DMM for automotive use defaults to DC for some reason and I have to switch it over. Is there any DC in HVACR? I ain't never seen a mag jumper til watching your videos. I just ordered a couple because I haven't figured out how to operate croc clips without wanting to attach them to my nose as jewelry while troubleshooting and getting boogers on them. I'm running spare wires from now on so I can switch brown wires for green ones. Excellent color choices by way. Do you have any interior decorating tips videos?

[@acservicetechchannel]

Yes measure almost everything in AC. There is DC in variable speed motors and flame rectification. Thanks

[@renenarvaiz8676]

Having an issue where the blower turns off in cool mode but will not stop in heat pump mode even when the when the thermostat is turned off

[@doughill4070]

Sometimes my fan runs all the time and the house gets hotter and hotter even though the heat pump is not on .It does it about 2 times a month and I have to turn it off at the breaker .Sometimes it work fine .

[@acservicetechchannel]

While this is happening, try pulling the 24v thermostat face off and see if it continues to run. If nothing is calling at the time from the tsat but the fan is running and you remove the 24v face off, you would know if the tstat is the problem. Start there, thanks Doug Hill!

[@doughill4070]

I have pulled it off and it still runs and keeps heating

[@acservicetechchannel]

Do you have electric resistance heat strips powering too or is it just the fan? So at least you have one thing out of play knowing the tstat is good so far. Are you getting 24v from g to c in the air hander?

[@acservicetechchannel]

I would only troubleshoot this with the electric res off and the fan off to stay safe. I would turn the power off and disconnect these items and then turn the power on to take the voltage readings to figure out what is going on.

[@doughill4070]

I do have heat strips but they have never had to come on ,I turn them on to burn the dust off ever so often .But something is making heat ,it's not as much heat as the pump makes but if it's 50 outside the temp inside will keep rising. I think thats why the fan is running.

[@CINCYB0Y]

I have a system that will not shut off after reaching the desired temperature. I have it set to heat at 68. When it get to 68 the heat will kick out but the fan keeps running pulling in cold air until the temp reaches 67 and then the heat will kick back in and run till 68. This is a none stop process. What do you think? Amana M# PHA24B0002A S# 9212231454 with a hunter 44760 thermostat

[@acservicetechchannel]

After turning the power off and removing the thermostat face plate and turning it on, does the fan still run? Do you have 24-28.5 volts between the G and the C on the control board of the package unit?

[@CINCYB0Y]

The fan does not run after turning off power. The fan will stop and not turn on until power is back to unit. Checked the volts and I am getting 15.9 volts on Fan = G and common = C

[@acservicetechchannel]

What happens when you turn the power off and then disconnect the g wire off of the terminal block and make sure it doesn't touch any other metal in the furnace and then turn it back on?

[@CINCYB0Y]

Sorry for the delay. I work second shift. I pulled the green wire off G= Fan and the heat pump kick on first then 2 to 3 sec later the blower kicked on. Temp set to 60 and it is 63 inside.

[@acservicetechchannel]

So Randy, is the blower shutting off when the heat meets the temp set at the thermostat now with the g off of the terminal block? Also that post not the last one but before that I was asking if the blower keeps on when you turn the power back onto the unit with the face of the thermostat off. I was trying to see if it was the thermostat that was the problem. It would also be good for you to watch these about heat pump thermostats and therm wiring. -- kzbin.info/www/bejne/p5qkgKmAndZrldU -- kzbin.info/www/bejne/fpbRgIqLeb1rhrM

[@shaunmcknight7354]

My combo fan doesn’t turn on until I switch it to AC but then it won’t turn off after it reaches temperature. Any ideas? I pulled the thermostat but it did nothing.

[@BanjoPicker]

Cant you just pull the G Green Blower motor from the terminal and see if it stops? If not then its not the Terminal or stat that is shorted or bad..Correct? ?

[@acservicetechchannel]

Yes you certainly can start by pulling the g wire off of the control board first to figure out if it is a bad tstat, or wiring. I usually test things first with my multimeter before moving any wires but there are many ways to do it. This is just an example, thanks

[@rodneyfull]

I have a trane heat pump with a York air handler. The fan runs continuously. I have changed the thermostat. Replaced the thermostat wiring, and replaced the control board. The fan still runs anytime there is power to the unit. With or without the green wire. With or without the thermostat attached. The capacitor on the fan is rusted. The transformer looks ok. What are my next steps?. I have electrical heat as a backup source, so no rollout switch. No gas components.

[@acservicetechchannel]

It sounds like a safety switch is open. Did you shut the power off and test the continuity across each?

[@actechformallyyomama746]

You have a sequencer sticking. It needs to be replaced. Sequencers stage the fan and heat. Then cycle off with the fan first and last to go off. That stage is sticking. Probably have heat blowing as well. Possible to just have the fan only.

[@TheMaximomex]

If the t-stat wires were touching it would blow the fuse also.

[@johnboykin3128]

Board, short, or limit switch

[@themechanic4222]

My unit never shut off always run even the thermostat set up point on 72 and inside temperature 66 any suggestion . my house like on ice box please help. I did replaced the thermostat twice and still

[@acservicetechchannel]

Turn the power off at the indoor unit and take a picture of the tstat wiring. Then remove the wiring. Turn the unit back on to see if it still does it. If not, then it is the tstat wires accidentally touching somewhere. Just had that last week, and switched the y wire with a different color that I wasn't using, thanks

[@elanreally3522]

My AC, I don't know if it's the Blower Motor or what, but it keeps running AFTER I turn the CIRCUIT BREAKER OFF. When I turn the switch OFF, It turns OFF. I just don't get it. The problem is, I think eventually I won't be able to turn it off. This is a NEW Industrial unit. One year old. The fan recently broke and was replaced and this problem resurfaced. Should I call the AC repair guy? It's still under Warranty.

[@elanreally3522]

Oh, I forgot, Thank You.

[@joepah51]

Thanks dude... excellent top to most painful troubleshooting.. Found that my Rheem blower motor board relay was burned.. no idea why.. Voltage spike? The replacement board had many different connections so I hired a guy to replace.. works fine now.

[@acservicetechchannel]

Those board relays tend to be the thing that makes most boards go bad. It is typically due to high amperage or just the amperage of the blower motor over time makes the contacts fail, thanks!

[@joepah51]

@@acservicetechchannel I hope so.. I saved $80 by doing the troubleshooting myself.

[@victorvillegas3169]

I have Lincoln Navigator 2004 climate control after I turn it off still running how can I fix it?

[@acservicetechchannel]

Do you have 24v when you test it with a multimeter from g to c at the control board?