Baxi Solo 3 30 PF System Installation And Servicing Instructions page 28

6.0 Installation - Page 28
6.15 Connection and Flushing
1. Connect the gas, water and pressure relief discharge
pipes to the valves on the wall plate using the copper tails
supplied. Ensure that the sealing washers are fitted correctly
to the water connections.
2. Connect the filling loop and fill and thoroughly flush the
system (see system details, section 4.2 & 4.7).