The message OH4 is activated when the indoor temperature of the frequency is approx. 80 °C.
The indoor temperature is evaluated by the 8200 vector (15 - 90 kW), as well as by the 8200 motec (1.5 kW and 2.2 kW). It is monitored in addition to the cooling temperature (OH message). All other 8200vector / 8200motec devices only monitor the cooling temperature.
