Hot flushing of building water system

A water tempering system for flushing a water supply system of a building with water, comprising:

• a water heater receiving water from a first source and providing hot water;
• a second source of water;
• a mixing valve (MV) having a first MV inlet configured to receive hot water from said water heater and a second MV inlet receiving water from the second source, said mixing valve being adapted and configured to mix hot water and water from said second source and provide tempered water at an automatically controlled temperature to a tempered water supply system of a building;
• a pump receiving tempered water from the water supply system and providing the tempered water at a higher pressure to said second source;
• a first multi-flowpath (1MF) actuatable valve having a 1MF inlet receiving pressurized water from said pump, and an 1MF outlet in fluid communication with said first source, said first actuatable valve being actuatable to a first position in which the 1MF inlet is not in fluid communication with the 1MF outlet, and actuatable to a second position in which the 1MF inlet is in fluid communication with the 1MF outlet;
• and
• a second multi-flowpath (2MF) actuatable valve having a 2MF inlet receiving hot water from said water heater, and a 2MF outlet in fluid communication with the second MV inlet, said second actuatable valve being actuatable to a first position in which the second MV inlet is not in fluid communication with the 2MF outlet, and actuatable to a second position in which the second MV inlet is in fluid communication with the 2MF outlet.