DeDietrich Elitec DTG 1304 Eco.NOx/V Technical Instructions page 26

- measure the strength of the current between the tank and the
anode ; if the current measured is less than 0.1 mA, the anode
should be replaced.
Valve or safety unit
The safety unit must be periodically manoeuvred (at least
once a month). To do this, put the safety unit in the
drainage position. This manoeuvre evacuates any
desposits which may in time block the safety unit valve.
Failure to comply with this maintenance rule may cause
damage to the tank structure.
4.1 Operations to be carried out to check or replace the anode and descale the installation
The TAS titanium anode (standard)
The magnesium anode (optional)
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In hard water regions, we recommend descaling the tank annually in
order to maintain its performance.
- Remove limescale deposits in the form of sludge or strips in the
bottom of the tank. On the other hand, do not touch limescale
adhering to the walls of the tank as it provides effective protection
against corrosion and improves the insulation of the DHW tank.
- The exchanger will have to be descaled, if need be, in order to
maintain optimum performance.
1. Fit a new watertight seal to the calorifier flange
2. Cut the power supply to the boiler
3. Cut off the cold water supply and drain the DHW tank. To drain
though the safety unit, turn the unit to drain and turn on a hot
water tap (or a bleed valve) to allow air to enter.
4. Remove the front panel and the sensors.
5. Remove the cover (13 mm spanner).
6. Check the anode and replace it if necessary.
7. When reassembling, replace the watertight seal; to do this:
- Replace the lip seal and position it in the visit opening, making
sure that you place its lug outside the DHW tank.
- Position the retainer ring around the seal, making sure you place
the lug above the retainer ring.
- Fix the cover to the flange using *1 screws, tightening them
uniformly in a cross pattern.
8. Proceed with filling according to the instruction in the chapter
"Commissioning". Check the seal and the safety devices on the
calorifier after reassembly.
The flange mounting bolts must not be excessively tight:
6N.m± : use a torque wrench.
Nota: Approximately 6 Nm is obtained by holding the box
spanner by the small lever.
DTG 1300 Eco.NOx/V
Descaling
23/06/05 - 300002940-001B