What does the programmer do? The programmer tells the boiler when to be turned on or off. You can set it to activate the boiler during...

Are your radiators giving off a bad smell of eggs or similar when you bleed them of air? (the removal of air via the air vent) Then this could probably be a build-up of a chemical called Hydrogen Sulphide in the water. Hydrogen Sulphide which can build up in central heating systems not only causes a bad smell but will cause corrosion sludge and magnetite within your central heating system over time and will require removing. A few well known brands of central heating cleaner

By managing your boiler, you can not only ensure your home remains as comfortable as possible, but also boost its efficiency.