Watts Mixing Valve
LF70A-F-050 -  1/2 Inch

Lead-Free


Hot Water Extender Tempering Valve
Hot Water Extender Tempering Valves are used in residential water supply applications to mix cold and hot water to extend capacity of water heater storage tanks and hot water boiler tankless heaters. 

You can meet various installation requirements with the Watts 70A Series Hot Water Extender Tempering Valves. They are available in 1⁄2" and 3⁄4" [15 - 20mm] sizes, with sweat connections. Temperature range 120° to 160°F [49°- 71°C].

The hydraulically-operated thermostat opens a spring loaded check in the cold water inlet allowing cold water to mix with the hot water.

Maintenance is very simple, as the thermostat is easily removed and replaceable as a unit. Valve bodies are of brass construction that is recognized and required to resist corrosive domestic hot water conditions.

Product Application:
Hot water extender tempering valves are used in residential water supply applications. Recommended for tankless heater, water heater and solar installations


Product Function:
Adjustable temperature
control - mixes hot with cold
water to preset temperature.

Product Features:
• Brass valve bodies
• Simple maintenance
• thermostat assembly
• is easily removed and
• replaceable as a unit
• "FINGER TIP" Dial
• adjustment Cap
• Stainless steel spring
• with sweat connections



Product Warranty:
• 1-Year Limited Factory Warranty - see warranty details below 

Maximum Pressure: 150psi [10 bars]
Series 70A temperature range: 120°F to 160°F

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Watts 70A Mixing Valve Dimensions and Weight
		Dimensions								Weight
Size		A		B		D		*
in.	mm	in.	mm	in.	mm	in.	mm	in.	mm	lbs.	kg.
1/2	15	2-1/32	52	3-11/16	94	2-3/16	56	15/16	24	3/4	.3
3/4	20	2-3/4	69	4-1/8	105	2-27/32	72	1-3/32	28	1-1/4	.6

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HELP » Contact Customer Support
• Toll-Free help line offering product info and ordering support
• Online e-mail technical and installation support
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Installation Note: Valve should be installed by a licensed contractor

Product Installation: 
• Close both hot & cold water shutoff valves upstream of the valve
• Bleed pressure from the system.
• Remove the thermostat and bonnet assembly [A], which is
• hand-tight, from body and install valve body as illustrated in
• diagram. Valve must be trapped as shown.
• Reinsert Thermostat and Bonnet assembly in body and tighten
• knurled portion of bonnet securely with pliers or channel locks.
• START UP REQUIREMENTS: Open cold water then hot water
• shutoff valves. The cold water supply line to Series 70A valve
• should always be opened first to prevent possible thermostat
• damage.

HELP » Installation Manual[PDF Format]

Caution:
Periodic inspection by a licensed contractor is recommended. Corrosive water conditions, temperatures over 210°F [99°C], unauthorized adjustments or repair could render the valve ineffective for service intended. Regular checking and cleaning of thermostat assembly helps to assure maximum life and proper product function. Frequency of cleaning depends upon local water conditions.

Watts 70A Series Troubleshooting Guide
Problem	Cause	Solution
Fluctuating or erratic hot water temperature at fixture.	Heavy draws of either cold or hot water elsewhere in the system, such as clothes washer or dishwasher. Unbalanced pressures.	Hot water temperature control valves cannot compensate for this condition. Check valves in hot and cold legs to hot water temperature control valve would help but not cure the problem. Install balancing or throttling valves (shutoff valves) in hot and cold legs to hot water extender tempering valve and adjust accordingly for demand.
Hot water backing up into cold water line.	Hot water pressure overriding cold pressure.	Install check valve in cold water leg to hot water temperature control valve.
Cannot adjust water temperature to desired temperature.	Unequal pressures. Hot or cold temperature differential. Valve undersized.	A balancing or throttling valve must be installed in the cold water leg to the hot water temperature control valve to throttle or restrict the pressure. In most installations, the cold water supply line feeds both the hot water temperature control valve and the water heater or tankless heater. To compensate for the pressure drop through the heater, the cold water to the hot water temperature control valve must be throttled or reduced. Check water heater controls to verify that the water temperature is the same as the heater thermostat setting. Check gpm flow required versus gpm flow capacity of valve.
High pressure drop through hot water temperature control valve.	Valve undersized.	Install larger hot water temperature control valve.
Insufficient hot water during peak demand	Valve undersized. Heater or capacity insufficient for demand.	Check gpm flow required during peak demand period and size hot water temperature control valve accordingly.
Frequent failure of thermostatic element.	Thermostatic element exposed to extremely high temperature. Corrosive water conditions. (Buildup of mineral deposits) Electrolysis (pitting deterioration, etc.)	Check heater thermostat setting. Hot water temperature control valve must be trapped at least 8" to 12" as per installation instructions. Install check valves as recommended. Frequent cleaning of thermostat element and plunger would tend to prolong the life of the element. A small coating of FDA approved silicone lubricant in the piston area of the element would also help. Electrically ground the piping system or install dielectric unions.
All hot or cold water flows at hot fixture.	This problem will require considerable troubleshooting met. Minimum flow requirement for 70A series valves is 2 gpm.	Verify that complete installation instructions were followed: Is valve properly trapped? Check to see if thermostatic element has failed. Check to see if temperature control on water heater is set at desired temperature. Check to see if minimum flow requirements for valve size are met. Minimum flow requirements for 70A series valves is 2 gpm.

WARNING
Watts hot water extender tempering valves cannot used for tempering water temperature at fixtures. Severe bodily injury [i.e., scalding or chilling] and/or death may result depending upon system water pressure changes and/or supply water temperature changes. A.S.S.E. standard 1016 listed devices such as watts models L111 or MMV should used at fixtures to prevent possible injury.

The WATTS hot water tempering valves are designed to be installed
at or near the boiler or hot water heater. They are not designed to compensate for system pressure and/or temperature fluctuations and should not be used where devices tested to S.S.E. standard 1016 are required. These WATTS valves should never be used to provide "anti-scald" or "anti-chill" service.

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Product Manufacturer: Watts Industries Inc.

Manufacturer Warranty:
Watts Regulator Company warrants each product against defects in material and workmanship for a period of one year from the date of original shipment. In the event of such defects within the warranty period, the Company will, at its option, replace or recondition the product without charge. This shall constitute the exclusive remedy for breach of warranty, and the Company shall not be responsible for any incidental or consequential damages, including without limitation, damages or other costs resulting from labor charges, delays, vandalism, negligence, fouling caused by foreign material, damage from adverse water conditions, chemicals, or any other circumstances over which the Company has no control. This warranty shall be invalidated by any abuse, misuse, misapplication or improper installation of the product. The company makes no other warranties express or implied except as provided in this limited warranty.
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