When your heating is switched off in the warmer summer months, air can build up in the system. The trapped air means that hot water can’t circulate properly so your radiators will have cold spots or may gurgle when you switch your heating on.
To keep your oil heating system running efficiently, it’s a good idea to bleed your radiators each year which will keep your oil heating system running efficiently. You may also wish to do a visual check of your radiators throughout the winter months to see if any need bleeding.