maintenance of plumbing; repair of plumbing; plumbing installation, maintenance and repair; plumbing installation advisory services; advisory services relating to the installation of plumbing; plumbing maintenance advisory services; advisory services relating to the maintenance of plumbing; plumbing repair advisory services; advisory services relating to the repair of plumbing; maintenance of water purifying apparatus; installation of water supply apparatus; installation of plumbing; installation of plumbing systems; repair of water supply apparatus; maintenance of apparatus for purifying water; repair of apparatus for purifying water; repair or maintenance of water purifying apparatus; installation and repair of bathroom heating devices; routine servicing of heating apparatus; routine servicing of ventilating apparatus; installation, maintenance and repair of water supply apparatus; emergency servicing of water supply apparatus; plumbing services; drainage services; plumbing; cleaning of drains by high pressure water jetting; cleaning of drains; drain cleaning services; drain cleaning services by high pressure water jetting; cleaning of bathrooms; installation of rainwater drainage systems; installation of water pipes; installation of pipes; pipe installation; insulation of pipes; laying of pipes; installation, maintenance and repair of gas supply apparatus; installation of equipment and apparatus for gas and water supply; installation, maintenance and repair of gas, electricity and water supply apparatus; installation, maintenance and repair of apparatus for supplying gas; installation of gas supply and distribution apparatus; advisory services in the fields of construction, repair, restoration, maintenance and installation