COMcheck 101 Training: Service Water Heating Requirements
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Heat Traps
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Heat traps are required in the inlet and outlet piping of noncirculating water heaters.
- Heat traps are not required on circulating systems.
Some water-heating equipment has factory-installed integral heat traps. For equipment without factory-installed integral heat traps, heat traps must be purchased and installed in the inlet and outlet connections or field-fabricated by creating a loop or inverted U-shaped arrangement of the inlet and outlet pipes.
Heat traps are a simple and inexpensive means of preventing cooling of hot water in service water heaters by thermosyphoning of the hot water to higher elevated portions of the attached piping system. Thermosyphoning is based on the simple physical principle of natural convection. Given the opportunity, hot water will tend to rise and be displaced by cold water beneath it. The heat trap stops this process, thereby retaining the hot water within the insulated storage tank.
