D. Float Switch Check and Cleaning
(for Booster Tank Water Level Float Switch and Backup Water Level Float Switch)
If an abnormal input signal is found by “III.A. Diagnostic Procedure” or the error code “o1” or “o2” is displayed, check and clean/replace the float switches according to the procedure below.
1. Float Switch Check
To check the float switches, follow the steps below.
1)Use the “ON/OFF” button on the operation panel to turn off the unit, then turn off the dishwasher and booster tank power supplies. Lockout/Tagout to prevent the power supplies from being turned back on inadvertently.
2)Remove the front panel and top panel of the booster tank.
3)Remove the control box cover, and disconnect the CN8 connector from the control board (see “II.F.2. Control Board Layout”).
4)To check the booster tank water level float switch, check for continuity across the orange and red wires (#1 and #2) on the CN8 connector. Confirm that the float switch is open when the float is down and closed when the float is up.
5)To check the booster tank backup water level float switch, check for continuity across the pink and light blue wires (#3 and #4) on the CN8 connector. Confirm that the float switch is open when the float is down and closed when the float is up.
6)If any problem is found, repair or replace the float switch.
7)If the float switch is scaled up or dirty, clean it according to “2. Float Switch Cleaning.”
2. Float Switch Cleaning
Depending on local water conditions, scale may build up on the float switches. Scale on the switches can cause the floats to stick. In this case, the float switches should be cleaned.
1)Use the “ON/OFF” button on the operation panel to turn off the unit, then turn off the dishwasher and booster tank power supplies. Lockout/Tagout to prevent the power supplies from being turned back on inadvertently.
2)Remove the front panel and top panel of the booster tank.
3)Use a soft brush to remove scale or soil on the float switches, or wipe down the float switches with a mixture of 1 part of Hoshizaki “Scale Away” and 25 parts of warm water.
4)Rinse the parts thoroughly with clean water.
5)If the float switch is removed, replace it in its correct position. Be careful not to confuse the positions and directions of the booster tank water level float switch and the booster tank backup water level float switch. Make sure the floats can move freely in the vertical directions (see “II.A.2. Booster Tank”).
6)Replace the booster tank panels.
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