Businesses in the domestic appliances category supply equipment used for everyday household tasks, including cooking, food storage, cleaning and laundry. Products commonly include fridges and freezers, washing machines, tumble dryers, dishwashers, ovens, hobs, extractor fans, microwaves and smaller appliances such as kettles, toasters and vacuum cleaners. Some retailers also offer built-in appliances, replacement parts and accessories, with choices varying by shop. Services may include delivery, installation, connection and removal or recycling of old appliances. Repair businesses diagnose faults, replace components and carry out maintenance on a range of makes and models. Customers may be able to arrange repairs in their home or take smaller items to a workshop. Work involving gas appliances should be carried out by a suitably qualified engineer; Gas Safe registration applies to engineers undertaking gas work.