When installing a solar water heater a way is needed to turn the circulation pumps on and off. The most efficient way to do this is to have the pumps turn on when the temperature in the collector exceeds the temperature in the hot water storage tank.
This simple controller does exactly that. It was designed because the other controllers on the market were more complicated than necessary and many had wasteful anti-freeze circuits. These use valuable hot water to keep the collectors from freezing. Making matters worse is the fact that this occurs when hot water is at a premium, at night during the winter, and sometimes may require the backup water heater to turn on. This nullifies some of the benefits of having a solar water heater. The best way to do this is to allow the collector to drain back when the circulation pumps are not on. This does require a solar system designed to allow this so be sure to check before using the SC-1 controller in your installation.
This controller uses two thermistors (included) to sense hot water tank and solar collector temperature. When the temperature in the collector exceeds the temperature in the tank the controller turns on the circulation pump. When the tank temperature exceeds the collector temperature then the circulation pump cuts off.
The SC-1 is designed to be used with any water circulation pump, but just like many controllers on the market you will need a power supply and maybe a relay. These are both easy to find and may often be saved from the going to the landfill, but if not radioshack sales them very inexpensively.
You will need a dc power supply. Any DC power supply from 6-28 volts will work. Most homes in the USA throw 2 or 3 of these away every year anyhow. A solar panel could also be used.
You will need a relay with a coil rated for the same voltage as the before mentioned power supply you use. I.E. between 6-28 VDC and the contact rated for the circulation pump's voltage and amperage.
All necessary instructions for installation are included with the SC-1
I personally am using several of these and they work great and have given no trouble!
The SC-1 is warranted for 1 year after purchase. The buyer pays return shipping for warranty work.
This is a great deal. More adaptable than many other controllers and takes up less space.
Price: $39
Shipping in contengent U.S.: $10
