Every now and again, an electrical appliance will either generate interference on the power lines or attenuate the X10 signal, reducing the range of your X10 signals. This is when you need the X10 Appliance Filter. Your electrician will need to wire the Appliance Filter into the offending appliance and then the interference will disappear.

As the Appliance Filter blocks out interference, you could use it to isolate multiple 'noisy' devices on a power board, provided the total load is less than 10A.