Analog Temperature Differential Controller

USDT 2005 is a simple, two sensor unit designed to control a solar hot water system. It is very user-friendly requiring no digital programming or alterations beyond analog temperature settings.

A green LED illuminates when the supply temperature exceeds the return temperature by a programmable temperature difference (∆T.) Controller and pump are protected by a 3.15 A fast fuse.

To avoid overheating the storage tank, the pump stops when the return temperature reaches a programmable maximum temperature (TMAX). 


The information presented in this page is for guidance only - no part of this may be used for any agreement, whether expressed or implied, or to form any contract. THERMO TECHNOLOGIES reserves the right to change specifications and prices without prior notice.

The system diagnostics displays sensor failures. The suggested retail price for a controller and two sensors is $ 139.00.

Call Aurora Energy, Inc. with your payment information for immediate shipping.

  • Precise digital differential controller for efficient heat collection

  • Analog display of collector  temperature

  • Analog display of collector tank  temperature

  • Adjustable Delta T (∆T) differential from 4  to 24 degrees Fahrenheit (F)

  • Manual override of outputs for system testing

  • Over heating pump stop for system boiling protection (Adjustable from 70  to 210 degrees Fahrenheit)

  • Unit accepts both thermistor and PT 1000 sensors

  • Alarm indicator for warning in case of sensor failure

  • Status screen for indication of the current state of  the pump

    Power Connection
    • Power supply 120 V AC
    • Maximum load 3.15 A (75 W)
    • Phantom load max. 2 W
    • A surge arrester at the collector sensor reduces lightning damages to the controller internal electronics 

    Sensor Characteristics

  • The unit is supplied with two thermistor sensors
  • Sensor cables can be extended up to 500 feet using standard two wire cables
  • Collector sensor is supplied with a weather resistant terminal box and EMI impedance protector
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