Based on what we have been able to troubleshoot, this is due to excessive noise on the line generated by the local phone services.  We have seen this issue in some VOIP services. 

Below are some suggestions to fix it and/or work around this issue:

1) Contact your phone service provider and ask them to tune the power / voltage signal levels coming into your house's line to make sure they are normal.

2) Clients have been able to regain control of the unit by simply unplugging their blocker for a minute or so from the LINE cable.

3) Another way to reduce the noise is by using a line filter e.g. DSL filter (installing it in the LINE port of the call blocker), which has helped some customers reduce these ‘freeze’ conditions.  Buy it on eBay > DSL Phone Line Filter 

 Other clients wait for an incoming call to re-gain control of the unit.

5) Other clients have been able to eliminate the "freezing" effect by simply switching the patch cable that connects the LINE on the call blocker. 

 Other clients request an exchange for our new Landline Call Blocker model (

which has its own power supply and batteries -- (We will apply full credit for the price you paid, just pay the difference between what you paid for your call blocker and this model, and return the original unit to us).

If you still have questions, please contact us.