1. When on AUTO, IF at any time the refer loses the 120 input, the refer will try to light on LP. IF there is NO LP or a malfunction lighting on LP the CHECK light comes on to let you know that the refer will not operate in LP mode if required. That is the ONLY function of the check light
2. It will stay ON until you turn the refer OFF and put it back on AUTO.
3. You have a malfunction of the 120 Heating system on the malfunctioning refer. Odds are it is a Bad Heating element, IF you turn the refer OFF and restart and the Check Light does NOT come on
4. If you restart and the Check light comes on when on Auto, that means you have NO 120 volts to the refer or the 120 element Fuse on the rear control board is blown. Access the rear of the refer and plug a hair dryer or any 120 appliance into the 120 receptacle behind the refer to verify you have 120 power to the receptacle. Doug