© 2011
D 406 - 12/11
44 of 48
Error Message
Description
HEAT PUMP RETURN SENSOR OPEN CIRCUIT
Due to an open circuit (disconnected or broken wire), the control failed to read the heat pump return sensor.
The control still operates the heat pump, but the HP RETURN MAX and HP RETURN MIN settings are
no longer used. Locate and repair the problem as described in the “Test the Sensor Wiring” section.
TANK SENSOR SHORT CIRCUIT
Due to a short circuit, the control failed to read the tank sensor. The control no longer operates the heat
pump or backup. Locate and repair the problem as described in the “Test the Sensor Wiring” section.
TANK SENSOR OPEN CIRCUIT
Due to an open circuit (disconnected or broken wire), the control failed to read the tank sensor. The
control no longer operates the heat pump or backup. Locate and repair the problem as described in the
“Test the Sensor Wiring” section.
DOMESTIC HOT WATER SENSOR SHORT CIRCUIT
Due to a short circuit, the control failed to read the DHW sensor. As a result, the control no longer heats
the DHW tank. Locate and repair the problem as described in the “Test the Sensor Wiring” section.
DHW tank heating will resume once the sensor problem is corrected. The error message self clears
once the error condition is corrected.
DOMESTIC HOT WATER SENSOR OPEN CIRCUIT
Due to an open circuit (disconnected or broken wire), the control failed to read the DHW sensor. As a
result, the control no longer heats the DHW tank. Locate and repair the problem as described in the
“Test the Sensor Wiring” section. DHW tank heating will resume once the sensor problem is corrected.
The error message self clears once the error condition is corrected.
DOMESTIC HOT WATER CALL ERROR
A DHW sensor and a DHW call have been applied at the same time. The DHW tank will not be heated until
the DHW call signal is removed. The error message self clears once the error condition is corrected.
DEW POINT ERROR
The DEW POINT item in the adjust menu is set to ON, but no humidity sensor has been detected on
the network. Either install a humidity sensor on the network, or set the DEW POINT item to OFF. The
error message self clears once the error condition is corrected.
BOILER DEVICE LOST (b:01 TO b:24)
Each tekmarNet
®
device (thermostat, setpoint control, timer) has an address. The device with this address
on the boiler water temperature is no longer reporting back to the 406.
The device can be located by either the address, or by going to each device in the building, checking
that the LCD is on, and the tekmarNet
®
communication symbol is on. Trace the wires from the control to
the lost device looking for loose or damaged wires.
Note:
If you deliberately remove a tekmarNet
®
device, hold the Up and Down buttons to clear this error.
MIX DEVICE LOST (1:01 TO 1:24)
Each tekmarNet
®
device (thermostat, setpoint control, timer) has an address. The device with this address
on the mix water temperature is no longer reporting back to the 406.
The device can be located by either the address, or by going to each device in the building, checking
that the LCD is on, and the tekmarNet
®
communication symbol is on. Trace the wires from the control to
the lost device looking for loose or damaged wires.
Note:
If you deliberately remove a tekmarNet
®
device, hold the Up and Down buttons to clear this error.
Error Messages (2 of 3)
