Drains from hot water cylinder relief valves
- Valid from
- Information provider
- Ministry of Business, Innovation and Employment
- Information type
- Section 175 guidance
Guidance about the function of pressure relief valves in plumbing and drainage systems, including discussion of the requirements in Acceptable Solution G12/AS1.
The guidance was released after MBIE received several enquiries about drain lines from pressure relief and temperature and pressure relief valves discharging to a PVC-U plumbing and drainage system. In some cases, the PVC-U pipes and stacks melted causing a failure of the plumbing system and extensive damage.