You should pull up and remove weeds by hand as and when they appear. If it is a regular problem, you might need to reseal the paving. In extreme cases, the sub layer itself may need to be re-laid. You can use weed killer, however some paving can be discoloured by stronger weed killers.
Aberdaron
Aberdaron is a community at the western tip of the Llyn Peninsula in Wales. It is about 36 miles south west of Caernarfon and it has a population of 965.
The village was the last stop for pilgrims on their journey to Bardsey Island, which is the mythical island of 20,000 saints. A former fishing village, the village became a shipbuilding centre and port in the 18th and 19th centuries. Mining and quarrying became the major industries, and the port exported limestone, lead, jasper and manganese. After the Second World War, the mining industry broke down and Aberdaron developed into a holiday resort. At the west end of the community, there are the ruins of an old pier running out to sea. The beach attained the Seaside Award in 2008. The coastal waters are part of the Pen Llyn Sarnau Special Area of Conservation, which is one of the largest marine designated sites in the UK. The village is also a Heritage Coast and an Area of Outstanding Natural Beauty.
If your property in Aberdaron requires a replacement boiler, it's important that you compare and contrast a at least three quotations from vetted businesses before making a decision.