Topping up the Pressure of your radiators is just as important as checking the oil and water in your car.
Many modern heating systems are pressurised. There are many advantages to this including really efficient heat distribution and it allows the removal of components such as feed and expansion tanks. The only problem is that from time to time the heating system will gradually lose pressure and this lost pressure needs to be topped up. The following videos from Worcester Bosch clearly show how to carry out the “topping up” procedure. Have a good look at your boiler and see what video applies to your heating system: