Is it OK to dump very hot water from a heating system down a drain or sewer?

There is a Public Health Act regulation of 1936, which states that water should not be discharged down a public sewer at a temperature greater than 43°C, but in reality this is unlikely to be a problem when power flushing. However, do consider the risk of cracking a toilet pan if you discharge very hot water into it when power flushing.  more