Worcester Bosch Greenstar Outdoor Weather Sensor, External Temperature Sensor, Weather Compensation Sensor, Boiler Heating Control Accessory

Domestic boiler accessories are the parts that complete a boiler installation: flue kits, extensions, bends and terminals, plume management kits, programmers, room thermostats and wireless controls, weather compensators, filters, pressure relief valve kits and natural gas to LPG conversion kits. Boiler and flue packs are also included.

Flues

Flue systems are designed for particular boiler ranges, so use only the flue parts the boiler manufacturer lists for your model. Concentric flues run the air intake around the exhaust pipe and are commonly 60/100mm or 80/125mm in diameter; twin pipe systems use separate air and exhaust pipes. The installation manual sets the maximum flue length for each boiler, and every bend or elbow reduces the length allowed. Plume management kits redirect the visible plume from a condensing boiler away from where it could cause a nuisance.

Controls

Programmers set the times for heating and hot water, and room thermostats, wired or wireless, switch the heating according to the room temperature. A weather compensator adjusts the boiler's output using an outdoor temperature sensor. In England, gas and oil boilers need time and temperature controls, and when a combi boiler is installed one extra energy saving measure is also expected: flue gas heat recovery, weather compensation, load compensation or a smart control with automation and optimisation. Check that any control is compatible with the boiler, as some are made for one manufacturer only.

Safety

Work on gas pipework, appliances and their gas parts must only be carried out by a Gas Safe registered engineer. Oil boilers should be worked on by an OFTEC registered technician.

For replacement parts, see boiler spares; for thermostats and programmers, see heating controls.