I have a main sump pump ( only 1 year old) and a battery back-up. In the past when my main sump pump failed because of power outages, my back-up would automatically kick on like it's supposed to. Over the past two weeks my back-up has gone on at weird times (once when the well was dry). At first I thought my main sump pump float or switch was getting stuck because when I jiggled or moved the pump the back-up would go off. Now, at 5am this morning when Chicago is getting 3 inches of rain an hour, my back-up kicked off again. I went down and shook the main pump which is working, but my back-up won't go off. I have now unplugged my back-up because when i reconnect it, it immediately starts running again, but my main pump has been working fine all day. It's very stressful as my basement has flooded twice in the past two years. I'm afraid to leave the house now with all the rain we are getting because if my main pump fails, my backup is not plugged in. What would be causing my back-up sump pump to run non-stop????