Rheem 310 Series Service Instructions Manual page 61

TX Valve Replacement (Procedure 22)
Wear Personal Protective Equipment when conducting step 2 of this
procedure to reduce the risk of electric shock. Refer to Rheem Safety
Procedure on electrical testing.
1. Isolate the power to the water heater.
2. Remove the access cover and confirm with a multi-meter between Active and
Neutral, then Active and Earth, then Neutral and Earth terminals of the terminal
block that voltage is not present.
3. Remove the refrigeration section jacket (refer to Procedure
4. Recover refrigerant from sealed refrigeration system.
5. Remove the pipe insulation to expose pipe-work at the TX valve assembly and the TX
valve sensor.
6. Separate the TX valve sensor and capillary from the suction line.
7. Un-braze the pipe-work and remove the TX valve.
8. Braze the replacement TX valve into place and attach the sensor to the suction line.
Note: Ensure the sensor bulb is in good contact with the suction line.
9. Replace the receiver/filter drier (Refer to Procedure 20 – steps 4 to 7).
10. Pressurise system to 3000kPa and conduct a leak test. Refit and secure the pipe work
insulation.
11. Evacuate system to 100 microbar (30") for a period of at least 30 minutes.
12. Recharge system with the correct refrigerant. Refer to "Specifications – Refrigeration
System" table on page 3.
13. Restore power. The refrigeration plant should commence operation after a 30 second
delay.
14. Refit air inlet louver and jacket top.
15. Adjust TX valve if required (Refer to Procedure 23).
TX Valve Adjustment (Procedure 23)
Components within the refrigeration plant section will be "live" during the
adjustment process. Wear Personal Protective Equipment to reduce the risk
of electric shock.
The TX valve is supplied preset and should be installed with the factory setting (6ºC)
unaltered. This setting is calibrated for the lowest superheating and optimum evaporator
utilization. However, should it be necessary to adjust the superheat, turn the adjusting
spindle as follows: Clockwise = Reduced refrigerant flow, increase of superheat.
Anticlockwise = Increased refrigerant flow, decrease in superheat.
1. Remove the air inlet louver (refer to Component
Replacement - Procedure 10).
2. Remove the TX valve sealing cap (see diagram
opposite).
3. Using a 4mm Allen key back the TX valve adjuster screw
anticlockwise all the way out. Note: The adjuster screw is
recessed approximately 8mm.
4. Screw the adjuster screw in three full turns to achieve the
required superheat setting of +6ºC. Note: 1 full 360º turn
of the adjuster screw = 2ºC.
5. Refit and tighten the TX valve cap to a torque of 4Nm.
TM025 Rheem Heat Pump Service Instructions REV: B
Date of Issue: 02/08/07
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11).