Rheem Ruud TRD Reference manual

TECHNICAL SERVICE DEPARTMENT
Technical Service Bulletin
1-800-432-8373
How to Replace the Thermal Release Device (TRD)
Rheem Guardian System
Technical Competence, Product Confidence Page 1 of 4
1446 How to Replace the Thermal Release Device (TRD).docx
How to Replace the Thermal Release Device (TRD)
Tools Required:
Torx 20 screwdriver
Parts Required:
TRD Replacement Kit
with TRD
and inner door gaskets, spare screws and clips.
You can tell if the thermal
release device has been
activated. Normally, there is a
small glass bulb in the assembly.
If the assembly has been
activated, then the bulb is
missing. You will also see the
shut off plate rod penetrating
into the bracket assembly.

TECHNICAL SERVICE DEPARTMENT
Technical Service Bulletin
1-800-432-8373
How to Replace the Thermal Release Device (TRD)
Rheem Guardian System
Technical Competence, Product Confidence Page 2 of 4
1446 How to Replace the Thermal Release Device (TRD).docx
1.
Shut
off gas supply to water heater. Turn gas valve to
OFF. (Note your gas control may be different than shown
here.)
2. Remove jacket door to combustion chamber.
3. Remove the four tamper resistant screws at the corners of
the burner. You will need a #20 size TORX head tool.
Disconnect main burner supply tube, pilot supply tube
and piezo ignition wire.
4. Remove burner access door. Remove the old door gasket.
Clean metal surfaces.
(Gasket will be replaced during reinstallation of inner door.
See gasket shipping package for more replacement
instructions.)

TECHNICAL SERVICE DEPARTMENT
Technical Service Bulletin
1-800-432-8373
How to Replace the Thermal Release Device (TRD)
Rheem Guardian System
Technical Competence, Product Confidence Page 3 of 4
1446 How to Replace the Thermal Release Device (TRD).docx
5. Locate and remove the thermal release device housing. It
is in the middle of the combustion chamber toward the
rear. Grab the housing, push down and rotate it counter
clockwise 90 degrees. Lift, remove and discard.
6. Locate the spring clip. When the TRD failed, the glass
bulb ruptured allowing the spring to release. The spring is
located inside the combustion chamber. Look under the
floor shield above if not in plain view. Discard used
spring clip.
7. Place the TRD assembly over the damper rod. Line up the
shut off plate rod with the hole in the bottom of the TRD
assembly. Press down firmly until the rod seats. Rotate
the TRD installation tool 90 degrees clockwise. Lock the
TRD assembly into the flanges of the mounting bracket.
8. Check positioning of the TRD assembly. It should not
move. Shut off plate rod should not be visible.
9. Replace the gasket and burner access door assembly.
(Note door gasket color may vary.)

TECHNICAL SERVICE DEPARTMENT
Technical Service Bulletin
1-800-432-8373
How to Replace the Thermal Release Device (TRD)
Rheem Guardian System
Technical Competence, Product Confidence Page 4 of 4
1446 How to Replace the Thermal Release Device (TRD).docx
10. Reconnect the pilot supply tube, thermocouple, and main
gas supply tube. Reconnect the piezo ignitor striker wire.
11. Turn on gas and gas valve. Relight the pilot per the
lighting instructions. Turn temperature up high enough to
light the main burner. Allow main burner to burn for 10
minutes to ensure air shut off plate is open.
12. Reset thermostat to safe setting. Rheem recommends no
hotter than 120 degrees.
13. Replace jacket door to combustion chamber.