During the blocking period of a heat pump, the energy supplier (utility company) has the option to temporarily interrupt the electricity supply to the heat pump.
This helps to relieve the power grid during peak times and balance overall energy consumption.
The legal regulations for blocking periods can be found in § 7 of the German Federal Electricity Tariff Ordinance (Bundestarifordnung Elektrizität).
Please contact your local energy provider to find out whether a blocking period applies to you and what specific rules are in place.