Our Culligan system froze last night @ 20°. It went into emergency mode to prevent blowing the lines. Only way to fix it is call Culligan and they will reset it for $$$$. If you just unplug it and remove the back up battery and disconnect nthe mother board, wait 30 seconds and put it back together and plug it in, it resets out of service needed mode. THUS SAVING YOU $$$$. Culligan soaked us a lot until we watched them how to do it and now we don't call those bandits anymore.