The longest 0% period available at the time of writing is 31 months – see our. Millhouses plumbing & heating services are proud to be worcester accredited installers, corgi gas safe registered installers and which? trusted traders. Drainage law applies to both foul and surface water pipes the term foul waste does not just mean the waste from the toilet but also includes the waste from kitchen sinks, basins, baths, showers, dishwashers and washing machines etc. Be the first.