OpenSprinkler › Forums › Hardware Questions › OS water pressure surge when power goes off. › Reply To: OS water pressure surge when power goes off.
June 8, 2015 at 12:19 am #38257
I don’t think it has anything to do with valves. When the power is switched off, it looks like OS sends a split-second impulse to all lines, making valves jolt which in turn sends “seismic wave” along water pipes. Again, when power goes off, no sprinkler valve is open (as oppose to your suggestion about “the way they close”).