The system is designed to give a continual supply of gas, which it does by using only two of the four cylinders at any one time. When there is some gas in all four cylinders the window (shown as red in the diagram) is white. When a pair of cylinders becomes empty the window turns red and the change over system automatically begins to use the other pair of cylinders.
The arrow on the changeover system is an indicator to us as to which cylinders need replenishing and is for our use only, You should never change the position of the arrow as this will cause confusion.
Used correctly the customer should never run out. You will get into a pattern of checking the change over, perhaps weekly in the winter, monthly in the summer. As soon as the window turns red, this is the time to order your next delivery.
Gas Safe Register is the official list of gas engineers who are qualified to work safely and legally on gas appliances. It has replaced CORGI registration. Only use a Gas Safe registered engineer to fit, fix or service your gas boiler, gas cooker, gas fire and other gas appliances.
Always use a Gas Safe registered engineer
By law gas engineers must be on the Gas Safe Register. This has replaced CORGI registration and only engineers who are on the Gas Safe Register are qualified to work safely and legally on gas appliances.
You can find or check a Gas Safe registered engineer on the Gas Safe Register website www.gassaferegister.co.uk or by calling 0800 408 5500.