Thermo Products USDT 2004B T

T roubleshooting

In general, all of the settings in the menus Par and Men and the terminal should first be checked

if there is a malfunction.

Malfunction, but "realistic" temperature values:

• Check program number. It should be “0” (zero) for 2004B unit.

• Check the switch-on and switch-off thresholds and the set differential temperatures, page

8. Have the thermostat and differential thresholds already been reached?

• Can the pump (output) be switched on and off in manual mode? If a forced pump “ON”

and “OFF” lead to the appropriate reaction at the output, the unit is certainly in order.

• Are all of the sensors connected to the right terminals? Heat up the sensor using a

cigarette lighter and watch the display.

Incorrect display of temperature(s):

• -999 sensor short-circuit

• 999 no sensor reading - (open loop) interruption do not necessarily mean a material or

terminal error.

Overheating protection:

The Circulation pump may not be powerful enough to circulate the heat transfer fluid in the

solar loop with air pockets. To protect the pump, USDT 2004B will take over the normal

operation after the temperature decreases to an acceptable working temperature.

The sensor can also be checked without a measuring instrument by connecting the presumed

defective sensor to a terminal that works and checking the display. The resistance measured by

an ohmmeter should have the impedances shown in page 9.

The settings of the parameters and menu functions ex works can be restored any time by

pressing the down arrow (enter) while powering the controller. The sign that appears for three

seconds on the display is RESTOR for load factory settings.

If the system is not in operation while connected to the power supply, the 3.15A quick-blowing

fuse that protects the control system and the output should be checked and exchanged if

necessary.

As the programs are constantly being improved, there may be a difference in the sensor and

program descriptions. Only the enclosed manual (identical serial number) applies for the

equipment supplied. The program version for the manual must correspond to the equipment

version.

If the control system is found to be malfunctioning despite the checks described above, please

contact your retailer or Thermo Technologies directly. The cause of the error can only be

determined if the settings of the unit is known. The schematic diagram of the system in question

is a great help to isolate the potential problem.