Pilot Light Won't Stay Lit - How to Replace a Broken Thermo Couple on Furnace

When my pilot light wouldn't stay lit on my furnace, I asked a few plumber buddies about the symptoms and they both said it was the thermo couple. I replaced it and everything works fine now. Here is video of the replacement process. The whole thing cost $11! Please be aware that I am not a professional or any type of certified repairman - just a homeowner with a broken furnace - please take this video as such.
New thermocouple at amzn.to/2ZB5eWj

[@CreamOfBeats]

Paid a furnace guy $300 two years ago to get the furnace going, and today I woke up to a 50 degree house! I watched your video and hit the local hardware store up as soon as it opened. Thermo Couple cost me less than $9.00 at Ace Hardware and it took me a whopping 10 minutes to replace/install it. It was almost too easy! I can't thank you enough! If your ever in Detroit, beer is on me! :)

[@liz9388]

My husband recently took ill and I've been doing a lot of work that he used to do all by myself. Today the thermocouple on our gas furnace took a crap. I knew right away what it was but I had no idea how to fix it. This was by far the best video and easy to understand instructions. THANK YOU!!

[@20jazzfunkgreats]

certain persons have managed fine from these instructions. most grateful to luke for providing them

[@danceinparadise316]

I had been having problems for quite a few years with my furnace. I replaced the thermostat first and it did not help the problem. The next day, after watching your video, I replaced my thermo coupler (it was cracked!) and turned everything back on. My pilot light lit and QUICKLY!!! Usually I had the 'ticking sound' that lasted awhile + a 'clunking sound'--trying to light the pilot or everything would just stop. But now, my pilots lights quickly and has never worked this well! . ;) THANK YOU!

[@josejose2001]

I just cleaned ours with WD-40 and steel wool about a month ago. It's been working beautifully. Great video!

[@JustLewisNoClark]

Saved my day. Was able to heat the church up for a full congregation. Thank you and God bless.

[@jd6094]

The weather turned cold the last couple days, and in the middle of the night, last night, I woke up and it was freezing inside. I checked the pilot and it was out, but I couldn't get it to stay on. I have a 24/7 service contract with the utility co. Called and they could come out no sooner than a full day plus! You can call 24/7, but they don't come out 24/7! So we would get colder and colder as the house lost all heat and it would be 23° inside as well as outside. I searched to see if there was something I could do and came across your video. As soon as the home store opened I went and purchased a new thermocouple. It was fairly easy to install, though tight quarters and I followed what you did. It worked! Took a couple hours for the house to get back to normal but it's nice and warm now! Very well done video and very, very helpful. I normally wouldn't mess with a gas heater, but I felt I could fix it after seeing your vid... and didn't want to freeze my keester off for 24 plus hours. Great job and thanks!!!

[@mubarakalesmaily584]

I have the same problem and was waiting for the heating and cooling guy for 12 hours. . so I disided to fix it by myself and I started to watch videos on KZbin till I find your video. . it was very helpful. . thank you and God bless you.

[@samposine]

Thanks dude. Furnace repair bill for today: $11.79! Much appreciated.

[@vikram703]

Thank You Luke for this awesome information. Just in the middle of winter, I discovered that the water heater stopped working and tried to turn on the pilot and it won't stay lit. Saw your awesome video and it gave me confidence that I could do it. Went to Lowes and got thermocouple in $10 and replaced it. It just took 1/2 hour and it worked like a charm. A BIG THANK YOU for sharing your video. Just have to be careful and read instructions carefully and follow the advice.

[@mariemcd5201]

A great video! Not only did you show what to do, you clearly explained it and what the heck a thermocouple is! (Ok, as a little girl I followed my daddy around and tried to learn everything, but my mom wouldn't let him take me to the furnace area... Exploding gas worries?? Lol! As a single mom, I tip my hat to you for making me smarter today!

[@mercruiserm]

I didn't have to replace my thermocoupler. But ur video helped me in taking it apart and all it needed was cleaned. But thanks for the close up shots. Very helpful

[@20jazzfunkgreats]

great video. many thanks. i also read the following- make sure gas supply ok [flame blue, strong enough to cover top of thermocouple], clean thermocouple w brush then fine sandpaper if needed, should be positioned right in the flame so gets sufficient heat to do its job, make sure the copper tube isn't kinked. once again thanks- without you taking the time & trouble to share this a lot of people would be in difficulty. diff between hand to mouth and hardship in the case of one v close to me

[@sewashburn0529]

Thank you for your post. That is exactly what was wrong with my furnace when I woke up to a cold house. My pilot light would not stay lit. Your video and a quick trip to Home Depot solved the problem. $12 plus a little work beats a $100 service call plus $25+ for the part from the HVAC man. This is equivalent to people calling an electrician to reset their GFCI outlet.

[@bpw466]

Thank you very much for this video. I woke up this morning with no heat and discovered the pilot on my boiler was out. I tried to light it and it wouldn't stay lit after holding the button for well over a minute. I watched your video and had it up and running by noon time. . . and for only $10.00!!

[@winowmak3r]

Thanks for posting this man, it helped a lot. Got home from work and noticed it's about that time of year to finally turn the furnace on but it wasn't working. I can light the pilot but it won't stay on and I'm very much of the opinion that this is why. My thermocouple was pretty grungy. Gonna just wear a sweater to bed tonight and get to the store in the morning, you saved me a lot of money my friend, thanks!

[@rayjgold]

Even in 2019, your video is still helping people. Thanks

[@scotty4837]

My pilot has the same problem and when i searched i found your video, well! i rushed to home dept and bought the same thing for $11.00, then problem solved!!!! thank you very much!!!!!!

[@floresgl]

May GOD bless you for making this video. I saved money and my house is warmer because of you. I can not thank you enough.

[@cldsrmtns]

Bro. Lifesaver. Used your video... 12 bucks and a half hour later my furnace was up and running. Thanks man!

[@Ferretlover64]

THANK YOU for sharing this video...woke up this morning to a cold house...tried to re-light the pilot and ti wouldn't stay lit.... now I can do it my self and not pay the 150-300 service call that I have had to pay in the past !! ( for whatever reason, I have a furnace that has a lousy thermocouple life span) This was so helpful and appreciated..... again THANK YOU

[@mrtrek64]

Great video. I find that removing the entire burner tube with everything attached is much easier to work on.

[@mrmattkeyable]

Thank you kind Sir! I used this video to successfully replace mine. People who take the time to make How-to videos are saints!

[@Ruddgate]

THANK YOU THANK YOU THANK YOIU. I did it and all for 10 bucks. Your video was a blessing. You & yours have a great Holiday Season

[@stvbrsn]

Holy actual shit. I just replaced the thermocouple and got my furnace working again! Thanks in no small part to you and this video. A true gem.

[@echopapacharlie]

I just want to add that you should always check your work, especially on a safety-critical part like the thermocouple. After you install the thermocouple and get the pilot light lit, blow out the pilot light. You should continue to hear the hiss of gas. This is normal as it takes the thermocouple sometime to react. Within 30 seconds or so, the thermocouple should cool down enough (from the lack of fire) and shuts off the gas flow automatically. The hiss sound will stop. And also when you route the copper wire of the thermocouple , you should do it so that there is clearance to put the safety cover back on. If you didn't do it and had to jostle the copper wire to get the cover back on, remove the cover again and check both ends to make sure nothing came loose from the jostling.

[@rg2027x]

good tips, thanks 👍

[@binhnguyen-ll3mk]

epchen37 mm.

[@Swaygodeus]

Thanks man..went right to Valu got the part 12 bucks my old man came over and we had it fixed in about 15 minutes...probably saved me 200-300 bucks!

[@snarlingrabiddog5150]

Thank you for posting this. I have made a few videos and know its not easy and working on a furnace isn't the easiest thing in the world. You've saved folks a LOT of money and kept them from freezing. I removed my assembly and cleaned the soot off with steel wool. They say not to touch the thermal coupler with your fingers due to oils causing it harm to it. I don't know about that, but cleaning the soot off is a good fix before replacement, but if you're that far in, replacement is good.

[@jaidevbhola]

spot on. same thing happended to my furnace and i replaced the thermocouple ( according to this post) and it worked like a charm. one thing to note - home depot has a 24" and a 36" length thermocouple. i would recommend that you measure the length of the old one and the buy accordingly. it will save you a trip to return the one you don't use. :) other than that, just follow the video.

[@TwistyPuzzles]

This was exactly what I needed. Once I had the part and the know how, it only took me 15 minutes to get my furnace running again. Thank you, sketchyvan!

[@amysmith4296]

Thanks Luke. I'm going to try this myself tomorrow. Pilot light will light, and furnace fires up, but all flames die out within 2-3 minutes. my furnace is approximately 35+ years old. Had it serviced and cleaned a couple of years ago and had thermostat replaced. got a clean bill of health even for its age. I'm in Kansas City and its 20 degrees and the two electric oil radiators can't keep up. it's 56 degrees inside. furnace went out 3 days ago. thanks for posting this. if it is the problem, then I'll have saved $150+. if not, I'm only out about $10. thanks again!

[@donkeyrider]

I like how you said - "Thermo-couple replacement successful!" That was awesome. Thanks for your help.

[@douglascardinal7955]

L011°

[@cl00bie]

Thanks!!! You just saved me a couple hundred dollars. I had the same trouble lining up the two little screws. What I did was put one screw in the hole, and lined up the other one with a flashlight. When the top was lined up the bottom screw went in (with a little wiggling) then I put in the second one.

[@VELOC1RAPT0R]

Thank you! I got my furnace running again and it was going to be a cold night! A guy cleaned my furnace and knocked out the pilot light. With your video I was able to light it.

[@reelsworld6661]

Thank you. You saved me $100 on a service call. Job only took me15min. Part was only $12.00

[@highwaymanxx57]

excellent, I almost threw away my portable cabinet heater because of the same symptoms, its a butane fire, but the same principles apply, Im almost certain that a new thermocouple will get it working again, Thanks for this great video Luke.

[@C100RXP]

Thanks for a well documented thermocouple repair. You did a good job.

[@FWHMyers]

Thank you so much for such a clear, detailed, and exceptionally helpful video on replacing the thermo couple.

[@tbilecky]

This video helped me a lot. $15 and tenants not angry anymore. Yeah! Thanks for posting this!

[@lwild1970]

Brilliant. Thank you. You have saved me from getting ripped off by the local sharks. I successfully done this myself today and it works good as new. Many thanks,

[@josephdonnelly2663]

thank you so much, My elderly mothers heater went out and needed fixing on a Saturday. thanks to you the repair was made simple.

[@kellmunroe6050]

Great upload! simplistic yet informative, was able to replace mine in an hour. Thanks for the help.

[@BrokePencil]

Im an hvac guy. You did a fine job. Btw if your pilot goes out but relights fine your heat exchange may be clogged and causing dangerous blowback. Or your gas valve could be going bad

[@stephenhobbie3617]

Thanks for demonstrating how to remove the pilot light bracket and thermocouple clips! That was the part I wasn't quite sure about.

[@BillHobstetter]

Thanks for the great video. I have been trying to get some heating company out to do this, They want at least $85 service call and then charge a big price for the thermo couple so you saved me a bunch of money.

[@elmaestrokgb]

Great video. Thanks so much for posting. I couldn't get anyone to come out today and now we don't have to freeze tonight.

[@krasyschrib6721]

Thanks for sharing. Thanks to you, our old furnace start working again. And cost us only 11$ to fix it.

[@hectormorey2182]

Luke...thanks for the video!! I just swapped out my thermal coupler and now I have heat & house has not blown up. I didn't realize but I actually needed a 36" coupler, not the smaller 23" or 26". One tough part was connecting the pilot assembly back into it's place. On my furnace, you can actually remove the tubes with the jets where the heat comes out of. Thanks again!!

[@eboy1718able]

Wow this saved me money. Sears wanted to come in 3 days, but drove to homedepot and fixed it myself.

[@rg2027x]

cool video, thanks. clear direct & to the point. I'm gonna give mine a go in the next few days. Furnace is over 25 years old! Thermocouple never replaced and the pilot light won't stay lit. I'm kind of amazed it lasted that long. Had similar issue with a water heater last year. The problem was a bad thermocouple.

[@iForza]

just watched the video and I feel prepared to fix my thermo couple! but my wife is still insistent on calling a repair man. Great video man!

[@cedergrenpeter]

Thanks so much! I'm off to the hardware store to buy me a thermocoupler! Fingers crossed!!! Awesome video!!!!!!!

[@TexHen]

Great Video......Saved me some money...... spent $11 on my Thermocouple and my heater is back in action Thank You Once again............

[@Pootle132]

thank you for sharing after watching your video it gave me the confidence to replace the thermocouple on my boiler £5.14 and all up and running again... thanks again.

[@donnaslavens7395]

Thanks for the video! Now I can go home and replace my thermo coupler tonight!

[@mikehunt2190]

The thermocouple is basically a safety device, in that it detects a flame. When the pilot flame is lit it sends an electrical signal to the gas valve ( thermoelectric gas valve) so it "knows" that the pilot is on. Without it, if the pilot was to go out, the gas would continue to flow and you have a gas leak, or the valve would open to fire the burners, and you'd have a major gas leak. These idiots saying that its dangerous for you to fix it are full of it. You did everything right.

[@writewordsmp]

Thanks allot , my friend Luke replaced thermocoupler with your help we have heat and didn't donate to plumbers pool fund thanks great vid

[@Malaryush]

Thank you so much for this video! My furnace was out and it was getting pretty chilly in the house. I was quoted $140 to get the thermocouple replaced by a professional. Instead I spent $9 at Lowe's and had it fixed in 10 minutes. It's great to have heat again!

[@priscillachang5353]

Thanks for sharing this video. I think this is exactly what I need to do. Will attempt tonight. Keep fingers crossed.

[@TheOriginalSurfTheEarth]

Dude you rock. Hope you are staying warm! Blessings!

[@justinperry7906]

This was Straight to the point. I replaced mine in an hour and thats including the drive to lowes for the 8$ part. Thank you very much.

[@The1970Snoopy]

Thanks for posting this! We figured out that is what was wrong with our furnace, too!

[@weatherrecords]

Nice hitchhiker thumb you got there, pal. I'm gonna take my hitchhikers down to the hardware store and fix my problem. Thanks for the great vid.

[@lukeqstafford]

Matthew Lusk if there’s a better apparel invention than the hitchhiker 👍, I’ve yet to find it.

[@djcar5181]

Luke. Great work. looks like I'm doing this tomorrow, as I woke up Christmas morning to the same issue. Thanks for the video bro.

[@MoosicMauler]

Thank you very much! Was after hours, so I took it off and cleaned it with a wired brush and wala heat is on. Thank you for posting this.

[@peterhellmuth7384]

East Indian pronunciation of Voila!?!

[@AAS0929]

On my way to Home Depot now. Great job. Thanks for the video. Let's hope I can find the right one at the big box and get it all back together correctly. Thanks again. Andy

[@tonyd1149]

Thank you sir. I was able to get our furnace running again. (Pilot light would not stay on). Thank you again.

[@fsped09]

Thanks Luke, that solved my issue too. And after ten years the price is now $11.99 :)

[@bodymindspiritguide5592]

Thanks Luke, I think you just saved me $500 bucks... I appreciate you doing the video and how you explained everything

[@alanatzenhoefer5296]

Thanks for putting this video together...very clear. Swapped out my thermocouple. About $11 bucks at HomeDepot, and now we have a working hot water heater again. Thanks Man!

[@journeymann3305]

Awesome video. Just replaced mine and it's working perfect. Only thing I forgot to do was measure the length so I needed 36" vs 24". Thanks saved about $200 for a service call!!

[@BoWeava]

Thanks Brother! Off to the store with fingers crossed...

[@Cosimo7777777]

This is excellent. Well-paced and didn't skip and steps. Thank you!

[@michaelbarryrobson]

Thank you! This helped my resolve my issue with my garage furnace! Only $10.00 for the part too.

[@MrWhaatay]

Excellent. You are the first one who says what the purpose of the thermocouple is. I was wondering what happens with the gas if your pilot light goes out. Now I know.

[@MrTechnoBuffo]

There's fluid inside that thermocouple and when it heats up, it expands and completes a circuit. like an electrical circuit which tells the control that the pilot is on and when it goes out, the thermocouple cools down and the fluid retracts cutting off the circuit or "connection" which stops the flow of gas.

[@MrWhaatay]

+Leo Gutierrez Thank you for taking the time to explain it. I understand electronics and circuit but never knew what the purpose of the thermocouple was or how it works.

[@backbeatkeeper]

First off, you're an uneducated dork. There is no fluid inside of a thermocouple that is shown in this video. A thermocouple is two dissimilar metals (usually copper and tin, look at the word, thermo meaning heat and couple meaning two) that are closely bound to each other and when heated create a small amount of voltage, called millivolts, that hold the safety valve open. The only fluid that is present is the brain fluid that you seem to have lost.......LOL

[@MrWhaatay]

You're a liar. Metals simply being close to each other don't create voltage. Couple in this case means "to connect" as in a coupler. It doesn't mean two? What a stupid thing to say. The metal may touch to complete a circuit when hot and then retract and not touch when cold but they don't create a voltage.

[@backbeatkeeper]

Whatatay T en.m.wikipedia.org/wiki/Thermocouple Obviously you have no sense of humor about the couple reference but you are wrong about two dissimilar metals making a small millivolt. Read above Mr. Naysayer.

[@davidhahn5650]

thanks luke. gave me the confidence to fix this myself. my TC was mounted to a tube so it was a bit diff, was nervous bending that thin gas line. up and running.

[@MrArielM1]

thank you mine just went out on me this morning. You make it look fairly easy and you explanied it well.

[@danielmcgrane5698]

Thank you sooo much! Have zero HVAC experience and I just fixed my problem entirely because of this vid. All I had to do was clean off my thermo and that seemed to fix it.

[@conniebolinger6059]

Superb instructions, annunciated so nice, very thorough and exact, thank you, i will Tell everyone about your method of instruction, so refreshing. 😃

[@iLikeMike]

Hey Luke - we had the same problem where the fireplace wouldn't stay lit. Apparently the thermocouple on ours was OK but the thermopile was dirty. So we simply took one of those Scotchbrite or 3M pads to clean it and now it works. I posted a video on my channel if you want to see how easy it was. Thanks for your video.

[@lukeqstafford]

great to know! thanks for sharing.

[@andreamangroo5527]

This was a great video! I was able to replace my thermocouple by myself at 4:00am on the coldest night of the year, 6° weather. Thanks for sharing.

[@lukeqstafford]

Way to go!

[@DreamingTurtle]

Luckily, it's just my hot water heater that isn't staying lit. This was very helpful. Thanks!!

[@phreakincool]

Thanks for posting this Luke! 21 thumbs down, really? Must all have been from furnace repairmen. This is what is great about the internet. Information is shared and not hoarded.

[@michaelrojo6971]

yes , I agree with last 2. comments ..thanks to this video I was able to finally fix my issue with my wall heater..thank you very much for your help ..great video!!

[@paulfrost6951]

Thank you, last time this happened I called someone to fix it and it cost me 300 bucks for an $11.00 part. Took them about 15 minutes to fix. That is way to expensive for what was done.

[@hershellacey9405]

Outrageous isn't it?

[@marey8881]

Thank you so much for the video! you saved me $100s of dollars and i fixed it myself .Only spent $10

[@100babaj]

thank you for the very helpful video.. I am having the same issue with my water tank heater. Pilot not staying lit. I will try the thermo couple route and see how that goes

[@G1Main]

Thank you man! I love you dude!! You saved me from getting sick because of a freezing house.

[@canagica]

Lemme just say that I appreciate the time you took to make this video. Best bit was your excitement as the flames lit, which I shared a few moments ago after replacing my thermocouple. Thanks!

[@ARVon]

Mine is a bit different. But going for it. Thank you for sharing!

[@rchristie13]

Thank You, Great video... Just what I was looking for cheap and easy fix. saved me alot of money for a simple job that would cost me a lot of money if I hired a plumber. Thanks again...

[@PrettyTubs]

Hey man, your video just saved me 150 dollars. Thanks alot

[@downfall616]

awesome! thanks man! $8 part. 10 min fix (very tight maneuvering, took a couple extra mins)

[@millea8]

Great vid man, much appreciated! Bout to try this on my furnace, thanks!

[@afxma]

Thank you! This novice got the heat back on in my house.

[@mapalargo]

I loved it, thank you. I am going to spend a less cold winter. Very well explained, and easy to follow everything you were doing.

[@PeteTaylorRealtor]

Great job. Especially mostly one handed. thanks,

[@leeleesaysorry]

this was the problem with my fryer on my.good truck, thanks. I figured it out after your video! also nice sleve holes ;)

[@jamesbillet8954]

Nice job Luke. Thanks for sharing.

[@michaelb344]

Thanks for the video, great to understand exactly what was going on!