Where protection lives
Boilers and hydronic heating
Boiler water is heated, pressurized and frequently treated with corrosion chemicals. A boiler can push water backward into the supply, which is backpressure rather than siphonage.
The protection you will typically see
Higher-hazard, backpressure-rated protection on the makeup water line, assigned by the authority based on whether the system is treated.
Who decides
The water authority assigns the required protection by degree of hazard and enforces the test schedule. Requirements vary by jurisdiction; the authority's cross-connection control program is the answer to every "do I have to" question on this page.
What the owner should know
If your building has a boiler with a makeup water connection, expect the assembly on that line to be on a recurring test schedule where the authority requires it.
Common questions
Why do boilers and hydronic heating need backflow protection?
Boiler water is heated, pressurized and frequently treated with corrosion chemicals. A boiler can push water backward into the supply, which is backpressure rather than siphonage.
What kind of backflow preventer is used?
Higher-hazard, backpressure-rated protection on the makeup water line, assigned by the authority based on whether the system is treated. The assembly type is assigned by your water authority based on the degree of hazard, not chosen by the property owner.
How often does it get tested?
Testing is typically annual where required, on a schedule set and enforced by the water authority. A certified tester performs the test, tags the assembly, and files the report.
Other places protection lives
| Lawn irrigation systems |
| Fire sprinkler systems |
| Restaurants and commercial kitchens |
| Apartment and multifamily buildings |
| Medical and dental facilities |
| Car washes |
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