Question
Hi there,
I have a Nelson controller, and after I hooked up the compressor and tried to open the zones through the controller to blow out each zone, the controller flashed a symbol indicating no water supply present and it wouldn't work- so I had to manually open the bleed screws on the valves. The hose bib I was using was located after the backflow preventer which I turned off so I didn't blow air through it. What did I do wrong????
Thank You

Answer
Is this on a commercial building? You mentioned that the controller flashed a symbol indicating no water supply which means you must have a flow sensor installed on the system? What size compressor are you using? You deffinitly need to blow out the water before the backflow as well since that is going to be the first thing to break as well as being the most expensive. Please provide the details needed and I will be happy to assist.