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this is indicative of a different issue. It indicates we may have too high of a temp rise. With the unit running can you tell me what the temperature is at the return air grill and also at the register closest to furnace?
Thank you....by chance are you using a high efficiency filter?
the end result is you are running too hot...and actually wearing out the limit. It is cycling on limit as most furnaces never trip limit at all. Only if blower fails or filter plugged.
Basically the furnace is running hotter than designed and the safety limit (which there for rare trips) is being activated on a regular basis.
High efficent filters can cause this, blocked registers/returns, duct too small etc.......we can look at increasing the blower speed if you are game.
Thank you...coming from blower motor to circuit board...there are commonly red, black, yellow, blue etc (some colors can be different.)
Then at the board where theese wires attach will be terminals lik COOL, HEAT, LO or HI...
can you tell me what color wire from motor is attached to what terminal?
well someone already had this issue or could have even been done on start up.
Black is highest speed for ac
Blue is med high
yellow med lo
red is lowest...
red is factory set at heat. Black at cool.
then yellow and blue on Park which are dummy terminals to put unused wires.
Someone has already bumped your speed from red to to blue bypassing even yellow. The overheat has been an issue for sometime. You can buy the limits regularly but the type and brand of limit will not matter.
You need more registers, more return or something to get the temp down...if you have ac...check the bottom of the ac coil at furnace and see if plugged
Ok you want to leave black on cool.
Leave blue on Heat...What I am saying is that someone has already recognized the overtemp issue and already raised the blower as high as it will go.
Not only is this tripping the limit but is also costing extra in gas as the unit is cycling..
You will need to have some duct changes or the issue will continue.
same reason ignitors go bad...they are wearing out.
A normal cycle would be 1 glow one igniton blower runs, shuts off....yours is glow, ignition blower, trip, glow ignition, blow trip. Your parts are not bad.....they are getting 10 years use in one year. Whether ac was added, duct changed, blocked etc....
And the fact that the unit is already on blue wire shows this issue existed for a while...or...the red would still be on heat where factory put it. This has been going on and an attempted fix by changing speed.....changing speed, ignitors, limits, 130 plus register temp...all point to running too hot
I would just say get "this type part"...but it will not change the issue.
I really wish you the best...
Anything you can do to lower that output by 20 degrees...
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