If an individual chamber valve is filling continuously, this indicates that the emptying valve is not closing. This is caused by a solid particle on the membrane that keeps the valve partially opened. Replacement of the front panel is not necessary to fix the problem.
Simply disassemble the valve and clean the rubber membrane to solve the problem. Attached is a schematic of the valve components.
Follow these steps to disassemble the unit:
1. Unscrew part 10
2. Remove ring 9
3. Remove electrovalve box 8
4. Unscrew part 6 and catch it by its plastic component
5. Remove part 6
6. Remove spring 5
7. Remove part 4
8. Remove metal piece 3
9. Remove rubber membrane 2
Next, clean the membrane and inject air onto the valve hole to make sure that no solid particles remain. Once this is done, assemble the valve in the opposite order in which it was taken apart. Be sure that no pieces are missing in the reassembly.
Step by step instructions can be seen here.