It means seism switch is open.
If seism or stove tilts it will appear these words.
It means that there are some problems with vacuum Switch.
Such as door has not been closed properly
Combustion fan's speed should be up.
There is some leakage about the stove and so on.
You can press
If showing following words, such as:
It means temperature sensor 1 is short-circuit.
It means temperature sensor 1 is open-circuit.
!! ATTENTION !!
to exit the program state. Otherwise, keep pressing