Yoder Smokers Community Forum

Trying using my 640 today. Started up normally, but never flashed internal temp. No matter what temp I set it at it always displays it is lowering the temp and does not get over 150 degrees internally. Does this sound like a bad thermocoupler? If so are they are to replace?

Yes, thermocouple. Send an email to [email protected], with the serial number and build date from the door plate, your full name, shipping address and contact phone number, along with an explanation of what is happening.

Thanks Herb! Will do

First thank you for the great service!! I installed the new thermocoupler and that fixed the concern. I must have installed something incorrectly and looking for some help. When getting up to temp now I get a lot of smoke this never happened before. What would cause this? Also it wont hold a constant temp like it did before.

Not really sure what you are describing. Did you install the wires for the thermocouple like this


The thermocouple wires need to be fully inserted into the connection block up to the insulation (you can trim the ends of the wires if necessary), and there can be no stray wire strands outside the connection block. The wires must be in the locations illustrated in the picture.

Forgive me for butting in as I know when most of us do we just confuse the issue!

I have replaced two thermocouplers. Both times there was a small hopper fire before replacing. The first time I had to repair with permatex. If the smoke is acrid in nature you might need to clean out the hopper and check the seals.