So you have a minor problem ;)
Originally Posted by 313C3B3A67312C550 link=1242678911/0#0 date=1242678911
1: What model ?
2: What does the manual say ?
3: What type of water are you using ?
4: Was the magnet in a package such that it could float ?
5: What have you done or changes just prior to the Error ?
The Magnet may or may not be for level sensing - Could be but it also could be just to detect teh tank.
If there were SS probes into the tank then that suggests a conductance method... Depending on the water your using, that can be a problem.
In short, none of us here have ESP... So we need a little more info and detail.