GUARANTEE
We guarantee the Lawler Mixing Valve to be free from def ects in workmanship and material, and for
a period of one year from date of purchase, will replace any parts found by us to be defective. We will
not be held responsible, however, for any labor incidental to, or for any damages caused by defective
material. Each mixing valve is thoroughly inspected and tested under actual conditions at our factory.
Typical Installation
Install the mixing valve below the hot water tank or heater.
If this is not possible, pipe in a heat trap as shown in
Figure 1 with an approximate 2’ drop.
Connect a tempered water return line as shown in
Figure 1. This allows flow through both ports of the mixing
valve during periods of no draw.
If a dual temperature system is used, a separate
recirculating loop and pump are required to return high
temperature hot water to the water heater. See Figure 2.
Install an aquastat at the tempered water return pump.
Install the water heater per manufacturer’s instructions.
Setting The Mixing Valve To The System
1. After installations be sure to flush the system thoroughly.
2. Make sure the hot water supply is heated to normal
design temperature.
3. Close and tag all fixtures to ensure they are not used
during this procedure.
4. Turn off the recirculating pump.
5. Create a draw on the system greater than the minimum
flow rating of the mixing valve. All open fixtures must be
tagged to ensure they are not tampered with or used
during this procedure.
6. Allow water to flow through the mixing valve until the
water temperature is stable. If necessary, readjust the
mixing valve in accordance with the TEMPERATURE
ADJUSTMENT section of the installation manual.
7. Once the temperature is set, start the recirculating pump
and allow the system to reach set temperature.
8. Measure the water temperature at the return pump
and adjust the aquastat to shut off the pump should
the return water exceed the set point by 2 degrees
F. Set the low limit switch to restart the return pump
when return water drops 5 degrees F below the set
temperature.
9. Set the balancing valve in the full open position.
10. Shut off all fixtures and ensure there is no draw on the
system. The cold inlet to the mixing valve should be
warm.
11. Allow the system to run in this condition for at least 30
minutes.
12. In some cases, an increase in water temperature may
occur during a no draw period. If this occurs, slowly
close the balancing valve until the water temperature is
back to the original set temperature.
Figure 1
Figure 2
STORAGE
TANK
WATER
HEATER
HEAT TRAP
27” DROP
RECIRCULATION
PUMP
AQUASTAT
BALANCING
VALVE
CW
CW
HW
CV
CV
CV
CV
TO LOW
TEMPERATURE
FIXTURES
Water heater must
be installed per
manufacturers O+M
STORAGE
TANK
WATER
HEATER
HEAT TRAP
27” DROP
RECIRCULATION
PUMP
AQUASTAT
BALANCING
VALVE
CV
CW
CW
HW
CV
CV
CV
CV
TO LOW
TEMPERATURE
FIXTURES
TO HIGH
TEMPERATURE
FIXTURES
RECIRCULATION
PUMP
Water heater must
be installed per
manufacturers O+M
