There are a number of different reasons why a drain becomes blocked in. Boilertrust is a london based central heating company that offers bespoke heating solutions we specialise in boiler replacements, combi-boilers, boiler repairs and efficient systems. Our large database of local engineers cover a wide range of boiler types, including oil fired boilers, gas boilers and. Mr anderson is an experienced plumber who does great work! from rough to finish plumbing work chris is excellent in.