Yeah, even I have used them before and worked well for me. Still thanks a lot, I will buy another MAX maybe it's the issue and will let you know.
Hope the new one works
FYI:
This is the only problem that I'm aware of with the MAX31856
https://forums.adafruit.com/viewtopic.php?t=115474
Thanks @jim-p, I will go through it.
If you have a multi meter with mV , just connect the thermocouple to that , output is about 40micro volt/c. ( difference between the hot and cold ends ) So a quick flick in the flame you should see some voltage .
You can also check for continuity , and check you do have a type K thermocouple !