Specifications

  • Features

  • NoteNote
  • Retail priceRetail price
  • Operating voltageOperating voltage
  • Solar panel (or battery) nominal voltageSolar panel (or battery) nominal voltage
  • Pump voltagePump voltage
  • Uses standard 10K thermistor temperature sensors Order separately - 2 required per controllerUses standard 10K thermistor temperature sensors Order separately - 2 required per controller
  • Back lighted LCDBack lighted LCD
  • Pump control: ON/AUTO/OFFPump control: ON/AUTO/OFF
  • Adjustable differentialAdjustable differential
  • Adjustable max temperature shut down senses storage temperatureAdjustable max temperature shut down senses storage temperature
  • Over temperature warning for storageOver temperature warning for storage
  • Over temperature pump control for heat dump (option)Over temperature pump control for heat dump (option)
  • Freeze protection activates pump below set point of 1 to 36F (requires battery backup)Freeze protection activates pump below set point of 1 to 36F (requires battery backup)
  • Audible freeze warning if collector is below 34FAudible freeze warning if collector is below 34F
  • Displays temperatures in F or CDisplays temperatures in F or C
  • Displays historic high and low temperatures for collector and storage (resettable)Displays historic high and low temperatures for collector and storage (resettable)
  • Internal battery maintains temperature/status display 24/7Internal battery maintains temperature/status display 24/7
  • Pump running "green" LED indicator on front panelPump running "green" LED indicator on front panel
  • Switches up to 6 Amps (72 Watts) Or higher with external relays - see AccessoriesSwitches up to 6 Amps (72 Watts) Or higher with external relays - see Accessories
  • Replaceable 6 amp 3AG type fuse insideReplaceable 6 amp 3AG type fuse inside
  • Built in surge protection protects electronic motorsBuilt in surge protection protects electronic motors
  • Ambient Operating Temperature of controller -40 - 185F (-40 - 85C) Ambient Operating Temperature of controller -40 - 185F (-40 - 85C)
  • Dimensions (not including mounting ears)Dimensions (not including mounting ears)
  • 5 year limited warranty5 year limited warranty
  • DTC-1

  • Notesimple affordable
  • Retail price$98
  • Operating voltage3-32
  • Solar panel (or battery) nominal voltage12 or 14
  • Pump voltage12 0r 24
  • Uses standard 10K thermistor temperature sensors Order separately - 2 required per controlleryes
  • Back lighted LCDN/A
  • Pump control: ON/AUTO/OFFinternal switch
  • Adjustable differentialno
  • Adjustable max temperature shut down senses storage temperatureno
  • Over temperature warning for storageno
  • Over temperature pump control for heat dump (option)no
  • Freeze protection activates pump below set point of 1 to 36F (requires battery backup)no
  • Audible freeze warning if collector is below 34Fno
  • Displays temperatures in F or Cno
  • Displays historic high and low temperatures for collector and storage (resettable)no
  • Internal battery maintains temperature/status display 24/7N/A
  • Pump running "green" LED indicator on front panelyes
  • Switches up to 6 Amps (72 Watts) Or higher with external relays - see Accessoriesyes
  • Replaceable 6 amp 3AG type fuse insideyes
  • Built in surge protection protects electronic motorsyes
  • Ambient Operating Temperature of controller -40 - 185F (-40 - 85C) yes
  • Dimensions (not including mounting ears)2.5 X 3.5 X 1.25" (65 X 88 X 42mm)
  • 5 year limited warrantyyes
  • DTC-AT

  • Noteadjustable differential and max temp
  • Retail price$120
  • Operating voltage3-32
  • Solar panel (or battery) nominal voltage12 or 14
  • Pump voltage12 or 24
  • Uses standard 10K thermistor temperature sensors Order separately - 2 required per controlleryes
  • Back lighted LCDN/A
  • Pump control: ON/AUTO/OFFinternal switch
  • Adjustable differential5 to 35F
  • Adjustable max temperature shut down senses storage temperature80 to 200F
  • Over temperature warning for storage"red" indicator on front panel
  • Over temperature pump control for heat dump (option)yes
  • Freeze protection activates pump below set point of 1 to 36F (requires battery backup)no
  • Audible freeze warning if collector is below 34Fno
  • Displays temperatures in F or Cno
  • Displays historic high and low temperatures for collector and storage (resettable)no
  • Internal battery maintains temperature/status display 24/7N/A
  • Pump running "green" LED indicator on front panelyes
  • Switches up to 6 Amps (72 Watts) Or higher with external relays - see Accessoriesyes
  • Replaceable 6 amp 3AG type fuse insideyes
  • Built in surge protection protects electronic motorsyes
  • Ambient Operating Temperature of controller -40 - 185F (-40 - 85C) yes
  • Dimensions (not including mounting ears)2.5 X 4.75 X 1.25" (65 X 120 X 42mm)
  • 5 year limited warrantyyes
  • DTC-D

  • Noteenclosed version
  • Retail price$210
  • Operating voltage3-20
  • Solar panel (or battery) nominal voltage12
  • Pump voltage12
  • Uses standard 10K thermistor temperature sensors Order separately - 2 required per controlleryes
  • Back lighted LCDyes
  • Pump control: ON/AUTO/OFFselectable modes
  • Adjustable differential4 to 32F
  • Adjustable max temperature shut down senses storage temperature100 - 200F
  • Over temperature warning for storageaudible alarm
  • Over temperature pump control for heat dump (option)no
  • Freeze protection activates pump below set point of 1 to 36F (requires battery backup)yes
  • Audible freeze warning if collector is below 34Fyes
  • Displays temperatures in F or Cyes
  • Displays historic high and low temperatures for collector and storage (resettable)yes
  • Internal battery maintains temperature/status display 24/7yes
  • Pump running "green" LED indicator on front panelyes
  • Switches up to 6 Amps (72 Watts) Or higher with external relays - see Accessoriesyes
  • Replaceable 6 amp 3AG type fuse insideyes
  • Built in surge protection protects electronic motorsyes
  • Ambient Operating Temperature of controller -40 - 185F (-40 - 85C) yes
  • Dimensions (not including mounting ears)2.5 X 4.75 X 1.25" (65 X 120 X 42mm)
  • 5 year limited warrantyyes

Why solar power and not AC to run your circulation pump?

To quote Chuck Marken’s Article: “Pickthe Right Pump: Choosing a Circulator for Solar Hot Water Systems” in Home Power magazine (issue #121):

“One way to approach the DC and AC pump choice is to examine relative system efficiencies. The efficiency of some heating systems is rated by the relationship of the amount of energy output to the energy input. If you have a system that produces a certain amount of heat with half the equivalent electrical input, the “coefficient of performance” (COP) is 2. Produce four times as much hot water as the amount of energy input from electricity and the COP is 4. We can use this same methodology in evaluating the efficiency of SHW pumps. Using a utility-powered AC pump for your solar water heating system will give you a COP between 12 and 25, and this is an excellent value compared to electric water heaters, which have a COP of 1. But the COP will never be as good as a DC PV-powered SHW system. DC hot water circulation pumps can have a higher COP than AC pumps because there is no traditional energy input if a PV module powers the system. If you use a solar-electric module to power the pump, your COP is infinite—you’re not adding any input energy. The sun provides it all, and you get something for nothing after the initial investment. PV-powered systems are also immune to utility outages. This is a big plus with antifreeze systems, since the collectors can overheat on sunny days if the pump stops operating due to a power failure. An overheated collector can actuate the pressure-relief valve, which will make it necessary to recharge the system with antifreeze solution. In some cases, the overheating can be so severe that the antifreeze solution will be compromised to the point of needing replacement.”

 Download Manuals

DTC_App_Manual_cover Rev2DTC-AT manual cover.DTC-D_manual-small

Real Time Performance Statistics for 2 systems
that use the DTC-D Controller

Building Heat     Domestic Hot Water