How to adjust the Honeywell fan and limit part 2

[@eddierey5202]

Invaluable information for us younger folks who bought an old house! 👍🏼

[@waynegalvin4639]

Good series of videos on the limit switch, thanks for having them up for all to see.

[@johnobeidin7296]

Thanks. This is what I needed to fix my furnace fan turning on in the summer while my central a/c is not working. My attic hits 130 degrees and then the fan turns on and blows hot air inside my house. Will see how much this impacts my a/c bill from here on out. Another video identified the problem, but this was the method I needed to adjust it.

[@grayfurnaceman]

Glad it helped. GFM

[@Fireship1]

I’ve changed a bunch of these in the past that were installed and damaged by homeowners. They were rough with the install and had the control stick or not work reliably. Thanks for posting this video.

[@grayfurnaceman]

Welcome GFM

[@melvin292]

Since my comment is welcome, I will say again, nice video and well done. You always make an informative video.

[@lulutileguy]

thank you thank you took a little bit to find this appreciated

[@curtbarile]

The little whole at the beginning of the dial setting pointers is for locking the dial with a small rod/screw driver so you can adjust this, but holding it down is just as effective.

[@justa_dude]

Thanks, your videos are always informative.

[@grayfurnaceman]

Welcome GFM

[@chiwoody48]

Thanks, first video i see how to do it, I was wondering how to do it at one time. Simple thing to do buy if you never done it. it is complicated I would say, thanks again.

[@markharris9647]

Good video

[@samuelpinheiro1713]

watch a lot of your videos, very helpful! great tech, wish I could be your apprentice.

[@Ajengineering]

Nice

[@Spector_NS5_RD]

Great video. I sometimes struggle taking the flathead screws (I CAN'T STAND FLATHEADS ON FURNACES) that mount these. Once in a while, i'll just get so mad, i'll bash the entire fan limit off with a hammer. Don't get me started on screws that have been placed between the plenum and return on old low boys. LOL.

[@rileyevans4422]

What a helpful video, thanks😉

[@7mcgraw7]

Thanks for this video. Can you set the limit switch for summer (turn down the limits)? I used my auto/manual switch/button to get my fan/blower running in the summer and then the power went out when I had it set to manual and now the manual switch for the blower will not work. The fan will come on if the heat is turned on but will not come on by itself for summer use. Any ideas on how to reset the blower auto/manual switch?

[@grayfurnaceman]

You could set the "off" pointer as low as it will go, but you will have to heat the switch to get it to go "on" to get it to start. GFM

[@7mcgraw7]

@@grayfurnaceman Thanks! I tried that and it worked. I have had just the fan on all summer! Really helped to cool the house!

[@davidsmith5359]

Mr. Grayfuranceman. My old furance has the Honeywell limit switch like the one in your video. Only my unit has the 8" Insertion. Just recently, about 5 seconds after burner kites, I get a bang sound that appears to be coming from the limit switch. Everything works fine, I'm just getting the banging sound. Could this be the bi-metal spring getting hung up when it starts to move when heat hit the spring? My furance is an old Janitorial, and I have lived in house 27 years and had never had an issue but this bang/pop sound. I have searched everything trying to find if spring could be stuck on start up, and I could find nothing. Any help would be greatly appreciated. Thanks

[@grayfurnaceman]

I have never seen that switch make any noise. I would be concerned that you may have a crack in the heat exchanger and the noise is sheet metal of the heat exchanger moving as it heats. This needs to be looked at as it is a CO poisoning problem. GFM

[@GCRAAY]

1990’s Armstrong down flow. Shop furnace. My fan is kicking in before my limit switch hits fan on point. And then eventually starts clicking allot and the burner shuts on & off. It doesn’t start clicking until it’s ran a while. It’s a new switch & flame sensor. ?????

[@grayfurnaceman]

If the limit switch is shutting off the burner, and it is shutting down every 2 to 4 minutes, air flow is too low. Dirty blower? GFM

[@Guyhakverdi]

I think they are more reliable than modern ignition systems . Do you agree? I don't remember any of your videos for troubleshooting these.

[@grayfurnaceman]

The fan and limit did have their troubles. The only saving grace is when one fails, you replace the fan and limit, if the IFC control does not control the fan, you have to replace the entire IFC. GFM

[@gregdowns7876]

All old stuff was made to last or fixed not thrown out and buy a new one.my fan was sticking on

[@Hallnout]

Please explain why my furnace has this old school honeywell on the duct work above the firebox and why I also have a 3" limit switch type with a button on the end like in the first video in the firebox or plenum? Think I explained parts right?

[@grayfurnaceman]

Depending on its location, it could be a rollout switch or, if it is in the draft hood, a spill switch to shut down the burner in case of vent gas coming out of the draft hood. GFM

[@Hallnout]

@@grayfurnaceman appears to be used for thermostat. Only One small red wire running from honeywell down to furnace circuit board somewhere? Not sure w/o tearing apart. Working great don't want to mess with. Only asked to try and understand. Have new honeywell in box, was considering buying 3" button type to have for backup. Furnace acts up now and then. 1986 90+ bryant with ac. Thanks for reply.

[@fatato89]

Do I have a bad switch if the fan is stuck on?

[@grayfurnaceman]

Yes, if there is no white button on the control that is pushed in. That is a fan on button that is on some controls. GFM

[@danitinoco]

Hi Mr. Grayfurnaceman, My situation is: I turn on my honeywell thermostat on the HEAT position and increase the temperature. I hear the furnace starting but not blowing any air.... and when I turn the thermostat OFF, the system starts the blower for couple minutes and then shut off. Do you think is this related to the limit switch. Thanks in advance!

[@gman3109]

My furnace runs for about 5 mind before building up enough heat for the fan to run. Sounds like you're not waiting long enough

[@michellebowersox194]

Okay so what if you don't hold it down and you've already messed with it can you fix it without having to replace it right away because I just bought it and I didn't know to hold it down

[@x.y.8581]

If the furnace is not running as it should even though you have set the limits correctly, then it likely must be replaced - there is no "fixing" them.

[@dannytaylor3210]

Mine works ok until it gets real cold outside. Then it won’t let my fan come on and it becomes a cycle that the burner continues to run and i can’t get it to work until I cool it down with an auxiliary fan. Has mine failed? If I cool it down then run the fan continuously I have no problems.

[@grayfurnaceman]

Replace it. GFM

[@channelcatchaser9426]

Those things are a P>O>S right out of the box.