Calorex DIGITAL LOGIC AT800 Owner Operational Manual page 5

GREEN POWER LIGHT: This light indicates that the heater has control power.
WARNING: This is not a supply line power indicator and caution should be used since
more than one power disconnection may be required to isolate the heater electrically.
WARNING: If the optional Time Clock Override is installed, you must shut off the water
pumps main power disconnect as well to eliminate all power to the heater.
GREEN HEATING LIGHT: This light indicates that the unit is heating and the compres-
sor is running. The compressor starts after a 3 to 5 minute time delay. NOTE: The water
pump must be running at the same time in order for the heater to run.
LED READOUTS:
When the unit has power, the LED will display the current water temperature. When
pressing the thermostat buttons the flashing readout will indicate the set temperature.
The following are LED code readouts for the internal sefety controls that regulate the
unit for various reasons.
LF = LOW WATER FLOW LF = LOW WATER FLOW LF = LOW WATER FLOW
LF = LOW WATER FLOW LF = LOW WATER FLOW
This light indicates there is no water flow through the heater. The heater is designed to
shut off whenever the water pump is not pumping water through the heater. If LF LF LF LF LF is on
while the water pump is running, the water pump may not be supplying enough flow
for the heater to operate properly. During normal operation the heater turns off and on
with the water pump.
F = DEFROST MODE F = DEFROST MODE
F = DEFROST MODE F = DEFROST MODE F = DEFROST MODE
d d d d d
This readout indicates that the internal defrost safety control has disabled the heater.
During cold weather where the air temperature drops below approximately 45 to 50
degrees (depending on humidity), the low refrigerant pressure switch (or defrost con-
trol) is designed to disable the compressor only. Once the unit is in defrost mode the
compressor will shut off for 1 hour while the fan continues to help deice and warm the
air coil. After 1 hour the unit will attempt to restart. If the air temperature has increased
to the operational range the compressor will continue to run, otherwise the compressor
will return to the defrost mode for another 1 hour delay cycle.
HP = HIGH REFRIGERANT PRESSURE SHUT OFF HP = HIGH REFRIGERANT PRESSURE SHUT OFF HP = HIGH REFRIGERANT PRESSURE SHUT OFF
HP = HIGH REFRIGERANT PRESSURE SHUT OFF HP = HIGH REFRIGERANT PRESSURE SHUT OFF
This readout out indicates high refrigerant pressure. The high refrigerant pressure switch
is designed to shut the compressor and fan off if a heat buildup occurs for whatever reason.
Typically, the high refrigerant pressure switch will trip if the water flow through the heater is
restricted. It may also trip if the air flow is restricted through the heater.
TIME DELAYS:
30 second compressor delay when switching pool/spa modes.
5 minute compressor delay when T.C.O. enables in pool mode.
5 minute T.C.O. off delay when: switching from spa to pool mode, when temperature is
reached in pool mode, or if LF (low water flow) is displayed on LED.
If water pump loses prime there will be a 3 minute compressor delay.
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