Hello together, as seen from the thread title … it’s about my toilet Thetford C200 GW. The red LED at the top of the sink tank, which is supposed to display as soon as the faeces tank is full, lights up permanently now. Normally the LED is operated via a battery … but with me the LED is connected to the network of the caravan. Otherwise I would have just taken the battery out and looked at home. I “advantageably” got the explosion drawing from the pot at home on the Re. hner. Before I go: does anyone have any idea what the LED could bring to permanent light, whether the tank is empty? Is there a “swimming” in the tank that could be stuck? Greeting NoGolf