Filter
Top Products
36
g) Internal Booster Tank Thermistor Error (H3, H4)
• If the internal booster tank thermistor senses a temperature at or above 231°F (111°C)
(2.4kΩ), the thermistor leads are considered shorted and the internal booster tank heaters
de-energize, "H3" appears in the display, and the buzzer sounds.
• If the internal booster tank thermistor senses a temperature at or below -6°F (-21°C) (517kΩ),
the thermistor leads are considered open and the internal booster tank heaters de-energize,
"H4" appears in the display, and the buzzer sounds.
• After replacing the failed component, the alarm resets.
• See the chart below for possible causes and remedies.
Note: When this error occurs, the auto fi ll cycle will not start.
Note: See “III.E. Thermistor Check” and “IV.M. Removal and Replacement of Thermistor.”
Control Board
Connector not properly
connected.
Reconnect.
Thermistor
Connector not properly
connected.
Reconnect.
Open circuit (H4). Replace.
Thermistor senses abnormal temperature.
H 3 / H 4
Code Error
Item Possible Cause Remedy
Continues (internal
booster tank heater off).
Operation
Short circuit (H3). Replace.
Defective. Replace.
Defective. Replace.