I'm currently the owner of a Hottop B2-K that I've had for several years. Recently I took the machine apart for a deep cleaning. No big deal I do it a few times a year. After re-assembling the machine the factory thermocouple is reading higher than before. I have two other thermocouples installed through the back wall for ET and BT. I typically don't monitor the factory probe. The problem with the factory probe reading higher is that I'm hitting the maximum temperature of 428f. Once you hit that temperature the beans dump without warning. Before my roast ended with the factory probe reading between 390f to 400f, now it's hitting 428f. Any ideas? Can the probe be calibrated or should I just replace it? I thought about pulling it out and leaving it in the back of the roaster by the motor but I kind of like having the safety features.

The maximum temperature is 435; it's just the default that's 428. However, that is probably not very helpful for you, and this seems like a very strange issue to be having.

Page 15 of the B2-K owners manual...
"3) When the KN-8828B-2K displays a temperature of 428 F (220 C), the beans will be immediately
ejected. There is no override for this safety function."

Maybe it was 435f on the older models. When I had it apart I didn't clean the probe itself. I'm going to try that and see if it helps.

If you want to extend your roast you can cut back on the burner setting when you get around 400 +/- That way the temp will rise slower and you can get more time at the higher roast temps.

There is no "safe" way to override the max/safety dump temp without modifying the wiring inside the roaster.

I have done this so that I can restart the roaster at a higher temp (300 +/-) for back to back roasts but I would never use that to extend past the 428 that Hottop sets as their max allowed temp as I do not wish to have a bean fire.

If you wish to verify whether the thermcouple is reading correctly you can remove it from the back wall and drop it in some boiling water. Use a digital reading thermometer of KNOWN reliability. to compare it against

Also, check to ensure that the thermocouple is securely attached to the circuit board, as a dodgy connection will cause incorrect readings.

Alan

ajf wrote:Also, check to ensure that the thermocouple is securely attached to the circuit board, an a dodgy connection will cause incorrect readings.

Alan

Thanks I'll check that.