This will depend on the issue. However, many plumbers are also Gas Safe Registered, meaning they can undertake work on all aspects of boilers and central heating systems. It's best to look out for plumbers that display the badge of your boiler on their literature.
Bala
Bala is a market town and area in Gwynedd, Wales. Formerly a city district, Bala exists within the historical county of Merionethshire. It lies at the north end of Llyn Tegid, 17 miles (27 km) north-east of Dolgellau, with a population taken in the UK Census 2011 of 1,974. It is little bit more than one broad road, this being Stryd Fawr (High Street, actually "Great Street"). The High Street and its stores can be rather hectic in the summer season with numerous vacationers. Bala was ranked as having the 20th highest possible percent of Welsh language audio speakers in Wales by selecting department, in the UK Census 2011. According to the census, 78.5% of Bala's population can speak Welsh.