INSTRUCTIONS FOR SERVICING
SMALLER TM2020A VALVE
1. Remove screw, snap cap, and handle.
2. Loosen LTR set screw.
3. Turn off hot and cold supplies at screwdriver checkstops.
Remove M20-2C (CP) cover screws to release cover and
thermostatic control assembly.
4. To remove bridge assembly, TM-28-1-8B, remove pointer rod
nut (MU-10B) and pull bridge assembly off control rod.
5. To clean submerge bridge assembly in clean water or non-
corrosive cleaning solution.
DO NOT USE ABRASIVES!
Be certain thimble moves freely on port sleeve. Note! Driving
ball on thimble must engage coil bracket in assembling.
6. To disassemble bridge assembly, see drawing next page
(remove TM25-3A holder nuts with screwdriver in slots
provided).
7. Remove thermostat group from bridge assembly, and soak in
a non-corrosive cleaning solution.
INSTRUCTIONS FOR SERVICING
LARGER TM2020A VALVE
1. Loosen LTR set screw
2. Remove snap cap, screw and washer, friction spring and
pointer.
3. Turn off hot and cold supplies at checkstops. Remove TM-16
cover screws to release cover and thermostatic control
assembly.
4. To clean port sleeve assembly, (the thimble must move freely
on the port sleeve): unscrew the check nut as far as it will go,
then screw the port sleeve nut into the base. The port sleeve
and thimble may be lifted out. SEE DWG BELOW
5. Clean in a non-corrosive cleaning solution.
DO NOT USE
ABRASIVES!
The port sleeve should be reassembled in the
valve.
6. To clean thermostat group, remove coil sleeve stud and take
off thermostat group.
7. Clean in a non-corrosive cleaning solution.
8. When reassembling, make sure driving ball of thermostat
group engages the ball socket of the port sleeve assembly.
NUT
SLEEVE
PORT
SLEEVE
PORT
NUT
CHECK
THIMBLE
MU-10B
POINTER ROD NUT
BRIDGE ASSY
TM-28-1-8B
TROUBLESHOOTING INSTRUCTIONS
Note: Provide serial number when ordering parts for each valve!
SMALL VALVE
Repair Kit # 1/28Y (Packings &
Gaskets)
Repair Kit #R/28 (Rebuilding
Kit) or TM28-1-8B Bridge
Assembly
Repair Kit #R/28 (Rebuilding
Kit) or TM-28-G2
Thermostat Group
Repair Kit #2/28Y (Checkstop
Kit)
LARGE VALVE
Repair Kit # 1/200Y
Repair Kit # R/200N
Repair Kit # R/200N
Repair Kit #2/200Y
1. Leaks at stem.
2. Leak between valve cover and base.
3. Valve delivers either all hot or all cold water, or
will not mix consistently.
4. After cleaning or replacing port sleeve/ bridge
assembly, valve performance is not consistent.
5. Hot water by-pass into cold line(or cold into hot).
6. Supplies cannot be shut off completely. Supplies
leak at checkstop bonnets.
PACKING & GASKETS
PORT SLEEVE/BRIDGE
ASSEMBLY
THERMOSTAT
GROUP
CHECKSTOPS
6
