E1 error heating error

Possibility is the pressure chamber or hose (pressure chamber to sump) is blocked and the microswitch is being activated because the water is not entering the tank quick enough. Isolate from electric, remove lid and left panel (looking from the front). There is a plastic chamber bottom right of left side with two microswitches, either this is blocked or the hose that runs from it to the right and along the back of the kick panel and into the sump. Clear either or both (make sure all hoses are pushed true when repositioning). Could also be a failure with the heater or module.