Your heating system is struggling due to trapped air or low water pressure, which is causing the banging or whooshing noises you are hearing.

DIY fix possible

Check the pressure gauge on the front of the boiler; if it is below 1 bar, use the filling loop to top it up to 1.5 bar.Turn off the boiler and let the radiators cool down.Use a radiator key to bleed each radiator starting from the ground floor up to the top floor to release trapped air.Re-check and top up the pressure gauge to 1.5 bar again if necessary.