There are no obvious differences looking at the LEM PCB
It is marked on the box which it came in, or check your order
You can also give us the serialnumber and/or the stamped date code normallly \"BS.....\" with 4 numbers
Haven\'t opened the box yet this morning...
BUT
If it IS incompatible
Why does CCT9 (obviously on the LEM01) defined as zone type 26 work fine?
Surely it either works or it does NOT
No, that is not a valid conclusion. Comfort I and II logic work at different voltages, sometimes circuits may work partially or intermittently when they are outside their voltage range. If you have Comfort II LEM with Comfort I main board then that combination is not supported and should not be used