Solar Powered Differential Temperature Controllers

Improves the efficiency of solar heating systems!

Designed to control solar powered DC circulation pumps in closed loop solar heating systems,  these differential temperature controllers will improve performance by preventing a solar powered pump from running if the collectors become cooler than the storage tank.  This typically occurs on overcast days and early and late on cold days when there is enough sunlight on the solar panel to power the pump, but the collectors are not hotter than the storage tank.

The principal advantage of an off grid solar heating system is reliability.  A system that uses AC powered circulation pumps is at the mercy of the utility rather than a solar panel.  If the grid fails on a sunny day causing your pump to stop, you can cook the antifreeze in the collectors and risk a chemical cascade failure which turns the antifreeze acidic.  This can then rot your copper plumbing and cause an expensive system failure.

4 models of Solar Differential Temperature Controller
DTC-1 solar differential temperature controller DTC-AT solar differential temperature controller DTC-D solar differential temperature controller
Basic model.
Fixed differential is
less than 1 degree F.
Adjustable differential from 5 to 32F and max shut down or
over temp warning/shut down
 for storage tank adjustable from 80 to 200F.
Many features including audible freeze and high temp alarms,  stored max/min temperatures, digital accuracy.
Unit wires in between the solar panel and pump.
Sensors are attached to collector pipe, and storage tank wall.
Solar Differential Temperature Controller hookup diagram
Video overview of the product line