Sounds like the control panel got wet so it thinks you are pressing the lower temp button. The minerals within the water can leave a deposit or cause corrosion which electrically shorts out the wiring or interferes with the switches action. You might be able to clean the spillage using distilled water or 90% isopropyl alcohol. If you see green or rust you might try white vinegar or rust remover. Make sure the area if fully cleaned afterwards using cotton swabs.