I'm lost !! Did you have pressure last season ?? ... or is this a new system being tested for the first time ? If this is a new system it may be a design problem but if it worked brfore it should work now ... A bad electric valve could be a reason you are not getting pressure ... very sneaky they do not open all the way sometimes or the solenoid is rusted and does not open and flow enough ... open the electric valve manually .. What happens ? .. make sure all your manual valves are all the way open ... Double Check. Any leaks or broken heads ?? Check carefully could be a broken nipple somewhere. "It's a bad design .Also the impact rotor is higher than the valve(i don't know if this is allowed)" Sounds like a goofy design to me ... the rotor should not factor in much ... in theory you can subtract about .5 psi per foot of elevation above your supply source source ... the hose connection is not a good idea .. What flow do you need and how long a run ? "The wire connection is connected with duct tape and it has been raining,the controller is not working for the valve ,so i tested it manually. " Sounds messy .. get some water tight connectors at your irrigation supplier. Check fuses .. Better yet design a better system ? Good Day ..

You can flush the head by removing the nozzle and turning the zone on for a few seconds. If water comes shooting out, then the blockage is either gone or was never the problem. Also, check the filter under the nozzle for debris.

good one racket! poolguynj - sorry, didn't mean to confuse the uninitiated. This topic has been hashed out in lots of detail on this forum in the past. There is some good stuff related to this topic if you search for it. Pentair has posted some real world field test data taken over a few weeks time comparing variable speed to 2 speed technologies. The differences are not as great as you suggest and depend largely on the speeds the pumps are used and the length of time at each speed. Didn't mean to hijack....just thought that UK should know the biggest contributor to power consumption with pool pumps is pump speed. Keep the speed low and the power consumption is reduced exponentially regardless of pump technology. This is so important but yet I see variable speed owners on this forum who are running their pumps at higher speeds thinking they are saving money because it's a variable speed pump....not entirely true. The true savings come with low pump speed operation which can be achieved with a variable speed or a 2 speed. Obviously the variable speed has more flexibility than the 2 speed. Take advantage of the variable speed and keep the speeds lower than 1725 rpm whenever possible. This is where the variable speed pumps really have an advantage over 2 speeds. The 2 speeds cannot be designed to go much lower than 1725 rpm without efficiency falling off sharply as you suggested. By the way, I work for a major US company that manufactures variable speed motors and drives as well as standard technology PSC motors with multi-speed capability. I sell these components to the HVAC industry and work with their engineers daily to help meet their performance and efficiency needs. Hope this helps.

I'd start with checking the incoming pressure and flow rate. If that's good, I'd check to see if the controller valves were opening fully. Also, check to make sure all zones are not on at the same time as the system may be too large to do so with the available supply rate. JM$.02W