As my colleague Terry Burger mentioned in his article, “Temperature Control Devices,” devices that are certified to ASSE 1017, Temperature Actuated Mixing Valves for Hot Water Distribution Systems, are often certified to ASSE 1070, Water Temperature Limiting Devices, as well. So, what are the differences between the two standards? How are the testing criteria different for each standard?
As mentioned previously, ASSE 1017 devices are often referred to as “Master Mixing Valves.” These are devices used for controlling inline water temperatures in domestic potable hot water systems. The devices are to be installed at the hot water source. ASSE 1017 devices are sometimes used in hot water recirculation systems.
ASSE 1070 devices are water temperature limiting devices intended to limit the hot or tempered water temperature to fittings, such as sinks, bidets, lavatories, and bathtubs, to reduce the risk of scalding. This is achieved by manually setting the set point to 120°F or lower. A common misconception of ASSE 1070 devices is they are intended to prevent thermal shock. They are not. They do not control temperature; they merely limit the water temperature to the fixtures.
To certify a product to ASSE 1017, compliance with NSF 61 is required. However, an ASSE 1070 device only requires compliance with NSF 372. When certifying an ASSE 1017 device, compliance with NSF 61, Section 8 is required. However, a client may wish to also have an NSF 61 listing on their ASSE 1070 product. Since an ASSE 1070 device serves the end point fitting and is contained within the last liter of water, it must meet the stricter criteria of NSF 61, Section 9. The methods for Section 9 are different from Section 8, and the acceptable limits of some additives are lower. Therefore, if a manufacturer seeks to certify their device to both ASSE 1017 and ASSE 1070 to include NSF 61, they will need to show compliance to NSF 61, Section 9.
Lastly, ASSE 1017 devices can have flow rates over 40gpm, while an ASSE 1070 device is generally limited to lower flow rates, often tied to the fixture they are meant to be used with.
While there are different requirements for ASSE 1017 and ASSE 1070, it may make sense for a manufacturer to obtain certification for both. Should you have any additional questions, or wish to update your listing(s), please contact ASSE International at listingcoordinator@asse-plumbing.org.
