Hello... I have a 4 year old(give or take) electric 25 kw nortron furnace... the fan drops to low when the t-stat tells it to shut off... it stays on forever... only way to shut it off is with main breaker... no switches were tripped or touched... there are three switches on furnace itself... summer switch is set to heating... energy saver switch is set to cold weather... fan control switch is set to automatic... there`s also a green light on the furnace which says t-stat on... t-stat controls are set to heat and auto... this has been like this all winter... now fan won`t shut off... it`s stuck on low... on the t-stat when I switch to on instead of auto,the fan goes to high then back to low when I switch it back to auto... also on the t-stat is the heat/off/cool switch... on heat,the furnace goes to high and elements work... on off,the fan stays on low... on cool, the ac does it`s job with fan on high... so everything works like it`s supposed to except the fan goes on low and stays on... 25KW, 240 Volt D Series Electric Furnace
Model 21D25... no model # written on furnace... not positive on model #... how do I trouble-shoot this problem so I can buy whatever part I need?? which wires do I pull to test this and that?? please help... I`ll include a picture to help you guys... thank-you

Update... I went back to the furnace and now know why the fan stays on... it`s because even though my t-stat is switched to off,the element glows red when I unplug the fan wire... with the fan running,I couldn`t see the red... so now the problem is why does the element stay on??

Probably the sequincer is stuck. In the photo I`m seeing 3 sequencers directly under the heat elements. Find which sequencer is feeding the heat element that is not turning off,, sometimes you can tap-tap-tap the sequencer lightly with a screwdriver handle and the will come unstuck,but it probably will happen again at a later time

You`re a genius... probably saved me some coin... been trying to shut that fan off for a while... tap-tap-tap and off she goes... thank you very much... maybe you can help me a bit more? What exactly is sticking?seems to me that there`s one part that sits on top of another at the sequencer... do I change the top part or the whole thing that you see in the picture?thanks again

Sorry but it comes in one piece so will have to change it out for sure

Anyone know where I can find a sequencer cheap?

Well, I was going to tell you where till I saw the word (cheap),, that kind of throws a monkey wrench into the answer., LOL ,I`m kidding, no they aren`t that expensive
Try around your home town at some HVAC supply houses,, some won`t sell to homeowners but again some will, I could pretty well tell you that it being an electrical part ,if you damage the new part it probably want be under warranty,you not being a trained contractor, you could probably find it on e-bay but the shipping/handleing cost puts it up there where its not so cheap,, maybe some others in this forrum can point you in another direction,

Goodluck