Lawler 66 Series Instruction Manual

temperedwater.com
5330 East 25th St.
Indianapolis, IN 46218
Phone [phone]
Fax [phone]
INSTALLATION &
MAINTENANCE MANUAL
Design and specifications subject to change without notice.
Please refer to temperedwater.com to ensure most
current data sheet and other design solutions.
CAUTION: When maintaining and adjusting the
mixing valve, all xtures should be isolated from
use. Lawler Manufacturing Co., Inc. recommends
that you work safely at all times and in a manner
consistent with the OSHA Lock/Tagout standard,
29 CFR 1910.147 and other applicable standards.
temperedwater.com/patents
M 66 E
ASSE 1017 Approved
ASSE Lead Free Certied
Certied to CSA B125.3
NOTICE! No mixing valve will work satisfactorily if improperly installed. We suggest, therefore, that you read
these instructions carefully before installing and follow directions as outlined. Handle the mixing valve with care.
Series 66
Thermostatic Water
Controller
This installation & maintenance manual covers all
congurations of the Series 66.
DIMENSIONS
Valve Number A N.P.T. B N.P.T. C
66-25 3/4” 3/4” 10”
66-50 3/4” 1” 10”
66-80 1” 1-1/4” 11”
66-125* 1-1/4” 1-1/2” 12-3/4”
66-150* 1-1/2” 2” 13-1/4”
66-200* 2” 2” 15”
Dimensions are for reference purposes only. For rough-in dimensions
please refer to Lawler’s Revit/BIM models found at temperedwater.com.
*66-125, 66-150 and 66-200 are not lead free certied
71762_66.pdf
B
A A
C
CAPACITIES – GPM SERIES 66
Pressure Drop PSI 5 10 20 30 45 60 Min.
Flow
GPM
Valve Number Capacity – GPM
66-25 9 12 17 21 25 28 4
66-50 18 25 34 41 50 57 8
66-80 28 39 54 66 80 91 12
66-125* 43 60 85 103 125 144 19
66-150* 52 72 100 124 150 174 23
66-200* 64 96 133 165 200 230 30
1/2 gpm when properly installed in recirculated system.
CAPACITIES – LPM SERIES 66
Pressure Drop PSI 5 10 20 30 45 60 Min.
Flow
LPM
Valve Number Capacity – LPM
66-25 34 45 64 79 94 106 15
66-50 68 95 129 155 189 216 30
66-80 106 148 204 250 303 344 45
66-125* 163 227 322 390 473 545 72
66-150* 197 273 379 469 568 659 87
66-200* 242 363 503 625 757 871 114
*66-125, 66-150 and 66-200 are not lead free certied

Checking Hot Water Shut-Off
Allow full hot and cold water to ow through the valve for
one minute. Shut off the cold water stop and check valve
only. The hot water should be reduced to a negligible
amount.
Failure to do so will indicate:
a. The hot water supply is not 20°F above the required
maximum temperature setting.
b. The plunger is sticking and requires cleaning or
replacement.
Inspection and Cleaning Valve
Shut off the hot and cold water supply to the controller.
Remove bonnet #19. To replace pusher O-ring #18,
remove pusher #21 from bonnet #19 and replace O-ring.
Reassemble in reverse order.
With the bonnet assembly off the valve, remove thermostat
#22 and check and clean (see g. A). Unscrew bottom plug
#14 and remove valve spring #13 and plunger #12 (see g.
C). If the assembly does not slide out, remove the plunger
with liner #11 and gently tap plunger until it becomes free.
Clean and polish the liner and plunger with very ne emery
cloth until plunger moves freely in the liner.
With the liner out of the valve, replace liner O-ring #10.
If the piston or liner is nicked or shows signs of excessive
wear, it should be replaced.
Temperature Adjustment
Valves are normally factory set for a maximum 110°F outlet
temperature, or that stamped on the label. If it is desired to
change this setting, proceed as follows:
While allowing water to ow through the controller:
1. Remove screw #1.
2. With a 5/32 allen key, turn adjusting screw #2
counterclockwise to increase temperature or clockwise
to decrease temperature.
3. When temperature is correct, replace screw #1.
If outlet temperature desired is 15°F or more higher
than that stamped on the label, contact the factory or a
representative for a special thermostat.
CAUTION: The liner and plunger cannot be dropped.
Please handle carefully. The liner must be inserted correctly.
Carefully examining the outside of the liner will reveal a very
small difference in diameter between the upper half and the
lower half. On reassembly, the smaller diameter must be
inserted rst through bottom plug opening.
WARNING: This product contains chemicals known
to the State of California to cause cancer and birth
defects or other reproductive harm.
(Installer: California law requires that this warning
be given to the consumer.)
For more information: www.oehha.org/prop65
Performance
The Series 66 water temperature controller is carefully
assembled and tested at the factory to mix hot and cold
water to any desired temperature within range. The
temperature of the hot water should be at least 20°F higher
than the maximum valve setting. The major safety features
are:
1. Failure of cold water supply causes the hot water ports
to reduce hot water ow.
2. Failure of hot water supply causes the cold water ports
to reduce cold water ow.
3. Failure of the thermostat allows both ports to reduce
ow of hot and cold water.
At each inlet of the controller is a union end stop and check
valve with removable strainer. Stop and check valves
prevent water from bypassing between the hot and cold
water supply lines. These valves should be fully open when
in operation.
Maximum Inlet Conditions
Pressure: 125 psi
Temperature: 200°F
Maintenance
The controller should be checked periodically and, if
needed, cleaned as outlined in “INSPECTION and
CLEANING VALVE.” To test for proper setting and operation
- proceed as follows:
1. Turn on full hot and cold water to the valve. The mixing
valve should deliver water at the outlet temperature
stamped on the label. Standard setting is 110°F. If the
outlet temperature is different than that shown on the
label, readjust valve according to “TEMPERATURE
ADJUSTMENT” procedure on page 2.
2. If after adjusting the outlet temperature the water stays
below the set temperature, see “CHECKING COLD
WATER SHUT-OFF.” If the temperature stays above the
set temperature, see “CHECKING HOT WATER SHUT-
OFF.”
Checking Cold Water Shut-Off
Turn on full hot and cold water supply to the valve, then
shut off the hot water stop and check valve only. Cold water
should ow through the controller momentarily then be
reduced to a negligible amount.
Failure to do so indicates that:
a. Plunger is sticking and requires cleaning or
replacement.
b. Spring #13 has lost its strength and should be replaced.
Lack of water ow can be normal on the rst test if the
temperature of the cold water is below 75°F. A quick
test is to momentarily turn on the hot water to warm the
thermostat. If ow then starts, the thermostat is good; failure
to obtain ow when rst starting, or when valve is cold, is a
normal reaction.

Series 66 Cut-away
1. Place a 3/8”
wooden dowel
rod into center of
thermostat then
place in 85°F water.
Make a reference
mark on the rod as
shown in g. A.
2. Now insert
thermostat into hot
water that is at least
20°F higher than
the set temperature
stamped on label.
3. The rod should
move out of
the thermostat
approximately 1/8”.
If the rod shows no
movement or can
be pushed inward,
a new thermostat is
required.
REFERENCE
MARKS
THERMOSTAT
Figure A
1
19
2
18
21
Figure B
See Fig. B
8
7
22
See Fig. C
42
10
13 14
41 35 34 33
32
31
30
2928
2726
25
24
Figure C
11
12
36
37
39
38
Item Description Part No.
1 Screw 7628-00
2 Adjusting Screw 8737-00
7 Bonnet Gasket —
8 Dome —
10 Liner O-Ring —
11 Liner —
12 Plunger/ —
Piston Liner Assembly Figure C*
13 Valve Spring —
14 Bottom Plug —
18 Pusher O-Ring —
19 Bonnet —
20 Label (NS) —
21 Pusher —
22 Thermostat —
23 Body Screw (NS) —
24 Liner Gasket, Upper —
25 Valve Body —
26 Tailpiece —
27 Union Nut —
28 Stop & Check Stem —
29 S & C Stem O-Ring —
30 S & C Bonnet —
31 Strainer —
32 S & C Spring —
33 Shutoff Disc Assembly —
34 S & C Body —
35 Seat O-Ring —
36 Pushrod —
37 Spring Retainer —
38 Relief Spring —
39 Acorn Nut —
41 Liner Gasket, Lower —
42 S & C Gasket —
(NS) - Not Shown
Item 42 only applicable to the 66-200 Kit
*Only available as assembly
Item Description Contains
1 Complete Repair Kit 7-10-12a-13-18-22-24-31-32-35
2 Piston & Liner Assembly 11-12a
3 Stop & Check Repair Kit 28-29-31-32-33-35-42
4 Thermostat Repair Kit 7-22
5 Bonnet Assembly 1-2-18-19-21
6 O-Ring & Gasket Kit 7-10-18-24-29-35-41-(42)
Repair Kits and Assemblies

GUARANTEE
We guarantee the Lawler Mixing Valve to be free from defects 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 ow 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 ush the system thoroughly.
2. Make sure the hot water supply is heated to normal
design temperature.
3. Close and tag all xtures 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
ow rating of the mixing valve. All open xtures must be
tagged to ensure they are not tampered with or used
during this procedure.
6. Allow water to ow 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 xtures 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