This will be useful someday i never knew the pepsi method, will have to try that out if and when my drain gets clogged in the future! Our bathroom installation & refurbishment service is based on superior workmanship which is low-priced. Dmc plumbing & heating today and let’s get started on your project! A combi boiler takes care of both the hot water and the central heating, hence the name – it’s short for combination. What's the cost of replacing your boiler?.