
42
6.
Maintenance Method
Replacement of Heater
If the heater should be disconnected or damaged due to deposit of scale, replace it by the
procedure below. (Also refer to Pages 38 to 41"6. Maintenance Method " in working.)
1. Turn "OFF" the earth leakage breaker of this unit.
2. Close the tap.
3. Turn "OFF" earth leakage breaker, and when more than 30 minutes has passed, open the front
door of this unit, and open the boiler water drain cock.
4. Open the left side plate of the body, loosen the four screws on the right of the terminal block, and
disconnect the heater lead terminal.
5. Pull the heater lead out of the grommet.
6. Remove the cap nut of heater, and pull out the heater.
7. Remove the packing and cap nut from the damaged heater.
8. Install the packing and cap nut on the new heater. At that time, do not touch with bare hand in
order to prevent soiling by hand.
Packing
9. Install on the boiler so that "YK-W-3" mark of the heater is faced up.
10. Feed the heater lead wire through the grommet, check the heater lead wire attaching position, and
secure to the terminal block.
11. Mount the left side plate.
12. Close the boiler water drain cock.
13. Close the front door, and then open the tap.
14. Turn on the earth leakage breaker.
15. The standby screen appears at the display window of the control panel.
16. Perform calibrations by pressing POWER key while holding down PURE WATER key and
DISTILLED WATER key. (Refer to page 24.)
(Calibration is performed for storing the standard temperature of the sensors in each heater under
normal operation in the inner controller. Performing calibration detects errors when the
temperature rises higher than the standard tempe 20
℃
.)
17. During calibration, a message is displayed at the message window of the control panel.
18. After approx. 5 minutes passed after starting calibration, normal operation starts automatically.