TESTO REXS, User Manual, Page: 38 / 42

8 Appendix
38
8.2.2. Cleaning of the Spark Ignition Electrode
The automatic flame ignition uses a high voltage spark. The electrode has to be cleaned
periodically to enable safe and proper operation. Clean the electrode after approximately 40
hours of operation. Switch off power and remove all gas connections and the power cord. To
remove the electrode, loosen the 3 M4 Torx screws that hold the pneumatic cylinder to the
electrode case. Use a T20 Torx® screw-driver. Pull out the electrode together with the pneumatic
cylinder. Clean the electrode tips and the concave ceramic surface using a dry towel or a fine
brush. Re-attach the electrode and pneumatic cylinder. Take care not to damage the sealings.
Fasten the screws.
8.2.3. Exchange of the HEPA Gas Filter Cartridges
Propane, nitrogen and air are filtered individually by HEPA filters. Though the gases are quite
pure themselves, the filter cartridges have to be replaced only once in a year. The filter cartridge
exchange has to be done by service personal from your local contractor.
Filter cartridges to be exchanged:
Filter Location Exchange interval
propane (C
3
H
8
) testo REXS control insert 1 year
nitrogen (N
2
) testo REXS control insert 1 year
compressed air prefilter testo REXS rack 1 year
compressed air HEPA testo REXS rack 1 year
compressed oxidation air prefilter testo REXS control insert 1 year
compressed oxidation air HEPA testo REXS control insert 1 year
8.2.4. Exchange of the Spark Ignition Electrode
To remove the electrode, loosen the 3 M4 Torx screws that hold the pneumatic cylinder to the
electrode case. Use a T20 screw-driver. Pull out the electrode together with the pneumatic
cylinder. Attach the new spark ignition electrode to the pneumatic cylinder. Take care not to
damage the sealings. Fasten the screws.
8.2.5. Cleaning of the Optical Flame Detection Unit
1. Disconnect testo REXS from electrical power and all gas lines. Let the system cool down.
2. Remove the protection cover that covers the burner (if mounted).
3. Disconnect the plug X302 (11.5 mm diameter 4 pin plug) from the small steel case at the
bottom of the burner.
4. Loosen the 4 M3 TORX® screws that attach the steel case to the transparent cover. Use a
T10 TORX® screwdriver. Remove the steel case carefully and disconnect the white 4 pin
PCB connector.
5. Loosen the M3 nuts that attach the PCB to the spacer bolts. Bend the PCB to the side
carefully. Do not stress or kink the wires that lead to the optical sensor!
6. Loosen the 4 M3 TORX® screws that attach the transparent cover to the burner bottom.
Use a T10 TORX® screwdriver. Remove the transparent cover and the optical sensor. Do
not lose the O-ring sealing or any other small parts!
7. Clean the burner bottom part. Use a vacuum cleaner or disconnect the steel mantled hose
and use compressed air.
8. Clean the optical sensor. Use a dry towel.
9. Re-assemble the transparent cover, the sensor and the sealings to the burner bottom.
Toghten all screws with care.
10. Mount the PCB to the spacer bolts. Fasten the nuts.
11. Connect the white 4 pin PCB connector, carefully assemble the steel case and fasten the
screws.