Low water pressure when sprinkler valve on


Old 08-28-16, 02:31 PM
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Low water pressure when sprinkler valve on

So everything in my house was fine until I had my main valve shutoff was replaced. Now I have extremely low pressure in the entire house and the sprinklers do not work. If I turn off the valve for the water going into the sprinkler system, the pressure in the house is fine. If I open the valve to send water into the sprinkler system, the water pressure goes to nothing in the main house. What could have caused this? I don't see any leaks at any of the sprinklers.
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Old 08-28-16, 02:52 PM
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Welcome to the forums.

You have an underground break. You haven't found it yet but if you keep the water to the sprinkler system on long enough you're sure to spot it.
Old 08-30-16, 07:44 PM
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Thanks for the reply. So I did some more testing and this is what I found. If I turn the sprinkler system valve on, the house pressure is fine. The pressure to the sprinkler system is so low that none of the sprinkler heads come up. Do you think this is a break? I'm not sure where to begin, I do not see any water coming up anywhere.
Old 09-01-16, 03:04 PM
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Can you watch the water meter?

1) Start with everything off (meter shouldn't move)
2) Then turn on the house valve. (does the meter move?)
3) Turn off the house valve and the sprinkler valve on but leave the zone valves off (does the meter move?)

The meter is the best tool you have for determining if you have a leak.

Prove that you do or don't - then go from there. It's possible you have an obstruction which is severely reducing the volume... but it's unlikely based on your testing so far.
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