Should these panels be connected to a boiler or to some other device?

These panels do not circulate water, but they produce electricity. This is why the panels are connected to an inverter that converts direct current electricity to 230 V mains electricity. The inverter is coupled to an electrical cabinet / fuse board, where all the household appliances and devices are supplied. The electricity generated by the Virte Aurinkokatto solar roof can be used in all the electricity needs of a property.