Review on Solenoid Control Wireless Contact T Mobile by Zachary Greene

I bought this cellular control relay to turn on a district heating system. The instructions are detailed (some concepts are a bit difficult, lost in translation, but much better than my Chinese). The biggest challenge was getting a cheap SIM card and a working data plan - a problem that had nothing to do with this great product. Rather, it is a problem due to the mass confusion in the cheap mobile phone market! The best deal I found was Speedtalkmobile (I bought this card: https://www.amazon.com/gp/product/B01H4D5EHO/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1 I got a monthly card for 5 Bought $.85, activated (without APN instructions) on activspeedtalk.com). After some testing, I plan to buy a $60/year plan that provides 1,500 articles per year. My wiring can be seen in the attached photo. Good product!