The Watts LFL70AT 3/4 is a 3/4" lead-free low-temperature hot water extender / tempering valve with NPT connections. It blends hot and cold water to hold a field-adjustable outlet temperature of 100°F to 130°F. It is a water-heater capacity extender and carries no ASSE listing — it is not a scald-protection valve. It features a brass body. Rated to 150 psi. This model is certified lead-free for potable-water installations.
This 3/4 inch hot water extender mixing valve is designed for domestic water supply systems and recommended for lower tempered radiant heat applications installed at or near the boiler or hot water heater. It consists of a lead free brass body, threaded connections, thermostat, stainless steel springs, and dial adjustment cap. The hydraulically operated thermostat opens a spring loaded check in the cold water inlet which allows cold and hot water to mix and can be replaced as a unit. The low temperature range is 100 to 130 degrees F (38 to 54 degrees C).
Features
- Lead free brass body construction
- Thread connections
- Thermostat assembly is easy to maintain, remove and replace
- Dial adjustment cap
Common Questions
- Can I use this at a lavatory — is it ASSE 1070 listed?
- No. This valve carries no ASSE listing of any kind — not 1070, not 1069, not 1016, not 1017. It is a hot water capacity extender, installed at or near the water heater so the tank can store hotter water while a lower temperature leaves the valve. It is not a substitute for a scald-protection valve and must not be used to protect a lavatory, tub or shower. For a lavatory choose an ASSE 1070 listed valve (Watts LFMMV or Under Sink Guardian); for a shower, an ASSE 1016 device.
- What temperature range does it deliver?
- The outlet temperature is field-adjustable from 100°F to 130°F. This is the low-temperature version of the series, intended for radiant heat rather than domestic hot water.
- Does it have integral checks?
- Not as a cross-flow protection package. The thermostat operates a spring-loaded check in the cold inlet as part of how the valve mixes, but this series does not carry the integral check-and-filter-washer set found on the LF1170 or LFMMV. Provide external checks if your installation requires them.
- Can I lock the temperature setting?
- No. Temperature is set with a dial adjustment cap and there is no locking or tamper-resistant feature. If the setting must be secured against tampering, specify a series with a locking adjustment such as the LF1170 or LFMMV.
- What happens if the cold water supply fails?
- This series has no shutoff on loss of cold supply — another reason it is not a scald-protection device. If the cold supply is lost, hot water passes through at tank temperature.
Specifications
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Type: Mixing/Tempering
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Size: 3/4"
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Connection: NPT
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Body Material: Brass
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Max Pressure (psi): 150
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Pack Quantity: 25
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Country of Origin: United States
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Warranty: 1 Year Limited
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MPN: LFL70AT 3/4
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Certifications: NSF-372
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Lead-Free: Yes
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ASSE Listing: None
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Install Point: Point of Distribution
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Outlet Temp — Min (°F): 100
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Outlet Temp — Max (°F): 130
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Integral Checks & Filter Washers: No
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Locking Temperature Adjustment: No
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Shutoff on Cold-Supply Failure: No
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Temperature Gauge Included: No
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Union Connections: No
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Applications: Radiant Heat;Water Heater;Tankless / Boiler
