Just purchased a new home and the weather is 8 degree in Chicago. Did as he stated and took the part out and tapped a few times. Put it back in and the pilot light started right up. This will get the family through the night! Thank you!!
Worked on my Trane XV80. I also found that the air filter was grossly clogged up. I'll have to check the part for continuity and replace the filter, but feel confident that I can resolve this issue and saved a ton of money. Thanks!
BE CAREFUL! This part is a thermostatic switch which shuts the furnace off if it overheats. Sometimes the part goes bad and shuts off even if the furnace is not overheated. However, sometimes the switch opens because of a potentially serious problem (like the blower fan failing to carry the heated air away from the furnace into the home). It's there as a safety device. This particular switch doesn't really reset by tapping. It resets by cooling, so you could take it out and tap it and think you have done something, but really all you did was let it cool and reset itself. (Typically these switches will open at around 180 degrees F and close again at 150 degrees F. The actual temperatures are printed on the switch.) So, while it's okay to bypass the switch with a paperclip during troubleshooting if you know what you are doing, NEVER bypass this switch during normal operation. Find out if it's a bad switch, or a good switch keeping another problem from burning up your furnace and your home.
Most codes like this will be caused by 'operator induced error'. You could also just turn down your stat and shut off disconnect. Secondary switch is actually your high limit control. It's actually a bi-metal disc and not a relay. Replacement is the only way to correct. Good job explaining it all
Thank you for the video! Had the same problem this morning (following a night of -20C...gotta love Calgary in April lol), and your video not only saved me repair costs, but it also helped me to get the heat flowing again. Even though cleaning the switch seemed to fix the problem, I ordered a replacement from amazon for $50 and will replace the old one once the new one arrives. Thanks!
The internet is undefeated once again! thank you! I determined it was the same limit switch after jumping it briefly. Nobody would sell one to me because I am not a dealer! So.....I tapped the switch and reinstalled it like you said...and VOILA! It worked. Wow. Just wow! this should buy me a day or two to order a new one from Amazon.
I can’t say thanks enough for this video, my furnace randomly stopped blowing heat last night at 3am and I couldn’t figure out why until I saw your video. I did exactly what you said and my heat is now working once again!
Thank you!!! My Trane is older (1989) and the part is different but in the same place. It has a tiny pin that I just pulled out, put back in, reconnected everything and it worked. I tried everything in my bag of tricks to fix my furnace with no luck. We FROZE last night. Woke up this morning and this was the last video (of many) that I watched before calling an HVAC repair shop on a Saturday and likely spending hundreds. So grateful!
Many thanks for this video! I have an XV90 and 2 days ago had the same issue. First I tried basic troubleshooting by switching off thermostat and unplugging furnace for 15 minutes before restarting again, to no avail. Then I followed your instructions, removed the limit switch, tapped it and put back in place and the heat was back to the delight of the whole family. I ordered a new switch online for $63 including shipping as a replacement. Thank you again. Your video save the day for us. With appreciation and gratitude.
Mad props man. Thanks for the video, hornets had built a nest in the intake tunnel, was choking out the furnace, removed the nest and the furnace works.
this part you talking about is LIMIT switch and is very important part of the gas furnaces or even in electric air handler .if your filter is badly dirty or cloged or capcitor moulfunction in blower motor it will stop gas valve and come on after it get cold and need to check it or replace it or correct problem in the system.thank you for explanations.
Hey much love all the way from Boston Massachusetts to Canada my man. Thank you so much for this video. I did what you said to do in the video and now I have heat.
My limit switch is black and has a single piece in the back. I ordered one for my Trane furnace and it looks like the one in this video. Is it fine to use? I bought this one because it was the closest matching ID to my current black switch (all other single black switches had totally different ID's).
remember to check the "resettable switch". Small button in the middle of the switch needs to be reset once you have checked all of the rest. The video shows him pointing to this switch at the 5:34 mark. It has plenty to do with your furnace NOT running if the switch has tripped and not been reset. That was the issue with mine (after changing the filter and making sure the pipes on the outside of the house were clear).
Worked to get me to the general problem, but mine was series in with another Pressure switch P08, which was the one that tripped and, it was resettable with a small button in the center. I changed my filter which seemed to be causing too much backpressure
This worked fore last night at 10pm as I have the same furnace and needed to know which item was the switch to hit. Got it to ignite again and the flames turned on. Hopefully it doesn't die out again but if it does these are fairly cheap to replace. Do you know if there is a specific model# to buy? I couldn't find one that said P06 on it.
I have the same problem on my trane xr90. Where did you find the part number for the limit switch - there so many with different temps available. Thanks!
I once drove 130 miles just to change an airfilter. I wrote it up. Poor guy wanted to kick himself in the nuts. I made sure to clean everything real good and hooked up his new sump pump for him just so he got something for the bill. He was a new homer owner. I never had any luck re using those limit switches either. Just replace it.
You need to find the restriction in air flow that caused the limits to trip. Bad filter, clogged return duct, restricted chimney, A/C coil dirty. You need to follow a specific set of tests in order to keep the greedy and often not too bright repairmen away.
It's not necessary to turn off the gas valve once the furnace is powered down. It's not a good idea to bypass any thermal switches. There's no relay in them - it's a bimetalic strip.
Hi, great video. I see that you replaced P06 with a P01 switch. Mine is P05 and furnace is xv95. I cannot find P05 in Canada, You think I can replace it with P01 or P06 ?
Change the filter and switch fan to on and the heat will be back on. This will make it work again and not have to do the paper clip until the part arrives.
The wires connected to the paper clip to test. If it works, you know what you will need. You can run like this, but make sure your filter is clean, if not leave out and replace asap. Also vent/exhaust pipes clear.
None of this worked for me. I can understand why this might limit switch might trip during operation (due to an overheating condition). But with my XR95, as soon as there's a call for heat the furnace blower and the induction blower starts and continues running but the gas valve doesn't open. Meanwhile getting the 4 red blinks. Tried bypassing the limit switch, but no go. Any advice?
Usally these high LIMIT switches preset at close to 300F and above that will open and shut the main burner for no gas flowing to burners until it get cold and again and again till to fix the problem.
As in the video, the little window on the lower door panel, look through that, and you see flashes, that will indicate a error code. I not a furnace tech, but thought the video would help
This is very poor information, if you continue to make these videos and people follow your direction and their house burns down, you are liable, those are not relays they are safety limit switches, you need a meter to verify if those limits are tripped open, please allow a professional to do these things
