Noisy Pipes when Irrigation System is running
Does your irrigation system make a loud noise (sounds like someone is hitting your house with a baseball bat) when your system is running? Well I know this can be an extremely frustrating issue with owners that have a two story home or a home with hardwood, marble or tile floors which are more and more popular in newer homes. I have heard some homes where it sounds like the copper lines in the basement are so loud one would think they could break. I am now going to go over the different types of noises. I would like to break the noise down into 3 different types. One would be when the system is pressurizing or basically there is a lot of noise for few seconds when each zone is starting but then goes away. The second type would be a steady noise during the duration of the time the system is running. The last type would be only when a zone is shutting down and will only last a second or two. Before I go into possible solutions, I would like to simply explain a few things about water needs: irrigation vs. house. When you flush a toilet in your home you may use 1.6 gallons per a flush. Now when compared to a residential irrigation system you would have to flush that toilet 6.25 to 7.5 or more times a minute, every minute to realize how much water you are using when irrigating. So if your overall run time is 2 hours it is like flushing your toilet 825 times. The reason for that explanation is when you flush a toilet or take a shower you are only using a fraction of the available water supply in your home. When a irrigation system is running it will pretty much demand the majority of the water supply, this is another reason why systems are best utilized early morning before everyone is up and either cooking or taking showers.
- System is making a loud noise when the zones are starting, then the noise goes away until the next station/zone starts or only on specific zones.
The cause for this is when a zone starts where water has drained out of the sprinkler heads the force of the water flow does not have any resistance and it will cause the pipes to make noise until the zone is under pressure. Also it could be caused by water turbulence in the interior plumbing of the home. Here's an explanation on how that may occur: When a irrigation system is connected to the house it is done by tapping into a water line (usually close to the meter) the tap is usually a Tee type fitting. Well when the irrigation is running it pulls water from both sides of the Tee fitting. We have found that if you place a check valve on the side of the Tee fitting furthest away from the meter so the water flows through the meter then out to the irrigation it will solve majority of problems associated with noisy pipes. By doing this your are preventing the irrigation system from pulling water from your house pipes which is usually the cause of the noise. If the noise is not that bad and only happens on a few zones then you may want to strategically place check valves on the zones that have elevation change to reduce drainage after that station runs.
- Steady noise during the entire time the system runs, sounds like a thumping noise.
Your water meter is making the noise and you need to have it replaced. What do I do if the water department says it is not the meter? Tell them you want a new meter or a larger meter, my experience is that if you are hearing a constant noise during the entire time the system is running that it is the meter and take a firm stance to have it replaced.
- Loud noise when the system shuts down
Water hammer, is caused when a flow of water comes to a fast stop and causes extra force to be applied to various fittings which causes the noise you may hear. You can strategically add a hammer arrestor, I would recommend a 3/4" arrestor and nothing smaller. There are a few different key locations to install it. Email me and describe your set-up and I will make a recommendation. You may also consider to install a pressure tank which will act like a large shock absorber to help reduce the force caused by the sudden stop of flow. You may consider zone valves that are designed to close at a slower rate.
If you are having any of these problems you should call a professional plumber or experienced irrigation professional. There is no one solution for every house, it is similar to finding a needle in a haystack. One thing to keep in mind that any irrigation system will make some noise since you do have water flowing at a high rate through pipes and meters and not to expect it to run silently.
Written by: Robert Diersing
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