Tekmar 256 Wiring Diagram | Free Wiring Diagram Assortment of tekmar 256 wiring diagram. A wiring diagram is a simplified conventional photographic representation of an electrical circuit. It shows the parts of the circuit as streamlined shapes, and the power and signal links between the tools. HVAC Systems tekmar Accessory Products (2 total) These are typical products that add more functionality to the Boiler Control 256. tekmarNet 4 Timer 033. Wireless Outdoor Sensor 087. Not what you were looking for? Try searching by words such as Boiler to see all matching products Product Literature - tekmar control s All technical literature for current tekmar products is available for download within this section as well as on the individual product pages. If you require technical literature for a discontinued product, enter the 3 digit product number in the search to find related literature. Tekmar 256 Wiring Diagram Gallery | Wiring Diagram Sample tekmar 256 wiring diagram – What is a Wiring Diagram? A wiring diagram is an easy visual representation in the physical connections and physical layout of your electrical system or circuit. It shows what sort of electrical wires are interconnected which enable it to also show where fixtures and components could possibly be coupled to the system.