Yamato Scientific WG221S Water Purifiers - Manual (Page 46)

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Maintenance
Exchange Heaters
● If the heater snapped or was broken, exchange the heater as follows.(Refer to P.40∼43 for
exchanging)
1. Turn “OFF” the circuit breaker.
2. Close the faucet.
3. About more than 30 min. later after turned “OFF” the circuit breaker, open the front door of this unit and
the valve to drain boiler water.
4. Open the left side board, loosen the four connecting screws in right side of terminal rack, and pull the
heater terminal.
5. Pull the heater terminal from the grommet.
6. Remove the cap nut of the heater, and pull the heater.
7. Remove the packing and the cap nut from the broken heater.
8. Install the packing and the cap nut to the new heater.
At this time, do not touch it with empty hands not to apply the finger marks.
9. Insert it into the boiler with the heater mark “YK-W-3” upward.
10. Insert the heater terminal into the grommet, and fix it in the terminal rack with checking the position of
installing heater lead.
11. Install the left side board on the unit.
12. Close the valve to drain boiler water.
13. Open the faucet after closing the front door.
14. Turn “ON” the circuit breaker.
15. Check that the STAND-BY lamp lit.
16. Push the calibrate switch in the upper part of the circuit breaker.
(The calibrate switch is a switch to memorize in the inside controller the standard temperature which
the sensor inside the each heaters shows at normal running. It senses malfunction when the
temperature become 20
℃ high more than the standard temperature for some reasons at the normal
running. )
17. At the calibrate running for 5 min. long, the indicator (1) of the operation panels blinks CAL.
18. After 5 min. calibrate running, the running become normal automatically.