Zone seemingly has low pressure
Hello all,
The irrigation system was put in around September of 2012. I paid a company to come out and winterize it since I don't have a compressor capable of blowing out the lines. Spring time is here so I took it upon myself to de-winterize it (activate) it. This is the first house I've lived in with an irrigation system so I took to the web to find out how I should do this without damaging the system. I read many articles and found a lot of common steps so I decided to go for it. I first went outside and closed the pep-cocks (not sure if I have the term right) on the backflow preventer. I also opened the the valve from the house to the backflow preventer all the way (it was left about 1/2 to 3/4 open over the winter). I had my wife turn on the valve about 1/4 of the way inside the house the water came out of the top of the backflow preventer as i expected. I then had her turn it on all the way. With the water flowing from the top of the backflow preventer I then slowly turned valve to the on position that leads to the sprinkler system. The backflow preventer fully activated and water stopped coming out of it. Hopefully the steps I took up to this point was correct.
I went into my garage and plugged in the electronic sprinkler control panel. I manually turned on each zone and ran it for a few minutes. I went around and looked to see if any sprinkler heads were buried or stuck, a couple were and I moved the dirt/debris out of the way.
Everything seemed to work as intended until I tested my last zone (zone 6). The first couple heads seem to have decent pressure but all the sprinkler heads after that had very little pressure. I turned off the manual run and unplugged the control panel. I went to the valve box on the side of the house and manually opened zone 6. The zone performed the same as before with low pressure. I went and observed each head to see if any were stuck or blocked and they seemed to be OK. Suddenly, the other sprinklers with low pressure started flowing properly. I thought great maybe something was just in the pipe impeding the flow. I went back to the valve box and turned it off (remember i turned it on manually). Went back into garage, plugged in the electronic sprinkler control box, and manually ran the zone again. To my surprise, it was back to the low pressure crap it was doing before. I thought I would let it run for a few more minutes like last time and it would come back to full pressure but it did not. I have now unplugged the control panel.
Having a irrigation system is new to me so I'm learning as I go. If my method to de-winterizing it was wrong please let me know so I do not repeat that mistake. Also, any ideas on what might be causing the low pressure for one of my zones will be greatly appreciated as well. I believe that because my system is new there should be some sort of warranty, but I fear it might get screwed if the cause of the improper function was the result of my actions.
My first thought was maybe the valve didn't open all the way which is why I manually opened it but that doesn't seem to be the problem. The only remaining things I can think of is that there is a break in the pipe (which seemed weird to me that when I ran it the first time full pressure came back eventually). My other thought is there could be some debris in pipe although I don't see how that could of happened especially since I currently have nothing but grass (no trees or bushes with roots that could of gone crazy).
Let me know thoughts, I look forward to your input!