Hi-

I bought a 1984 house and we use city water.

When I'm outside watering my lawn and someone inside the house flushes the toilet or takes a shower, the water pressure drops significantly to almost nothing.

If our washer starts up and I try to wash my hands in the bathroom sink the pressure drops too.

It seems that we can only have one thing open and the water runs normal. However, the water from the spigot or outdoor faucets doesn't seem as strong which I notice it when trying to wash my car using the different spray settings.

Has anyone experienced this??

Please help before I call a plumber and he tries to rip me off.

Thanks for all your help on this.

From what you describe it is clear that the VOLUME of water entering the house is too little.
This can be caused by either a partially closed valve) in the water supply line (check the main valve), or by a too thin section or partially blocked section of the supply line.

You have to check this in steps : first check the (outdoor) main water valve. If that one is fully open, test the maximum water flow just behind that valve. If that is sufficient, the problem is further in the supply line to your house (*1*).
If it is insufficient, it is for the water supply people to find and repair.

(*1*)At your side you can also measure the maximum incoming water volume near the house. Just to find out where the problem is located.
Note that the blockage can be due to dirt blocking the pipe, or by ground movement bending the water pipe till it starts blocking the water flow.

Success !

:)

First check that the valve at the street is completely open. Next check that the main shut off valve to the house is completely open. How is th pressure when you are only using one fixture? Do you have a pressure reducing valve. Check with the city to see what pressure they are providing in your area. Purchase a pressure test gauge like one shown, attach to hose bib and see what pressure you have.

As plumbers, we experience this all the time...

Most likely, you have undersized pipes. Even if you have excellent pressure in the house - you may have weak water delivery due to low volume.

But first, make sure your pressure regulator is not acting up.

First check that the valve at the street is completely open. Next check that the main shut off valve to the house is completely open. How is th pressure when you are only using one fixture? Do you have a pressure reducing valve. Check with the city to see what pressure they are providing in your area. Purchase a pressure test gauge like one shown, attach to hose bib and see what pressure you have.


It seems that my house doesn't have a main shut off. The only shut off valve will be the one at the street.

I forgot to mention that several months ago, I asked the city to check the water pressure and they replaced the unit at the street. I wasn't there to pick their brains but my wife said something about getting a plumber to pressurize/clean the pipes in our house.

When I use one fixture, the pressure is fine. The only fixture that I think doesn't have enough pressure is the front yard spigot.

Thank you everyone for your help.

If pressure on one fixture is OK then pressure is OK and problem is volume problem. If this problem started after replacing meter may they didn't turn on valve at street completely. Check there. Sorry you don't pressurize/clean pipes. Wife must have misunderstood.

I'd still ask city what the pressure was suppose to be. You have to have a restriction (valve) or pretty small line to house and low pressure to loose volume on second fixture when toilet is flushed.

If pressure on one fixture is OK then pressure is OK and problem is volume problem. If this problem started after replacing meter may they didn't turn on valve at street completely. Check there. Sorry you don't pressurize/clean pipes. Wife must have misunderstood.

I'd still ask city what the pressure was suppose to be. You have to have a restriction (valve) or pretty small line to house and low pressure to loose volume on second fixture when toilet is flushed.


I found this link regarding the service to clean pipes.
Low Water Pressure (http://www.vigilanteplumbing.com/Newsletter/Articles_and_Publications/Low_Water_Pressure/low_water_pressure.html)

"Plumbers sometimes can remove this kind of blockage (lime deposits) by blowing high pressure air through the water line. This is a relatively inexpensive task."

I doubt that 24 year old pipes are clogging up but anything is possible. You got some good pointers from several folks, its most likely volume and could be caused by a partially closed valve at the street. Call the city back.

Bob,

I was sitting here considering my response about blowing out lime and mineral deposits with air. I don't see, from a logical stand point, how it could work. All mineral deposits I've seen are very hard and securely attached. Other wise it wouldn't be there. If water under pressure doesn't dislodge mineral deposits, how can air. That is excluding pressures and volumes to a dangereous level. Even then water has a lot more friction than air.

Sport,
Check that the street valve is completely open, look to see what size pipe you have to the house. Even a 1/2 pipe will supply 3 fixtures under "normal" working pressure. If you have no or almost no volume when you open a second valve you must have something that is restricting pipes to almost a 1/4 size opening. Is you location known for high mineral deposits. Ask neighbors if they have ever had such problems.

Harold, that wasn't me who suggested blowing out the pipes. Maybe you got me switched with Sport. I think he neeeds the city to check the tap at the street.

Bob,
No, I'm just skeptical of the concept but don't know. Just wondered what you thought.

This is a loss of volume, pure and simple. This occurs when something's choking down the amount of water that's going through your system. When you open more the one faucet the lack of volume causes the pressure to fall off. I locate this by the process of elimination. Start where the water service enters the house. Open a hose bib near where the service enters and then go in and open a cold water faucet. Does that decrease the pressure? I assume your place's piped in copper with 3/4" mains. Correct?
Let me know what you find at the hose bib and we'll go from there. Good luck, Tom

I found this link regarding the service to clean pipes.
Low Water Pressure (http://www.vigilanteplumbing.com/Newsletter/Articles_and_Publications/Low_Water_Pressure/low_water_pressure.html)

"Plumbers sometimes can remove this kind of blockage (lime deposits) by blowing high pressure air through the water line. This is a relatively inexpensive task."

Sorry, but I think the enclosed article was not written by an experienced plumber.

Let us know if you got better "pressure" after your plumber "....blew your pipes"...

This is a loss of volume, pure and simple. This occurs when something's choking down the ammount of water that's going through your system. when you open more the one faucet the lack of volume causes the pressure to fall off. I locate this by the process of elimination. Start where the water service enters the house. Open a hose bib near where the service enters and then go in and open a cold water faucet. Does that decrease the pressure? I assume your place's piped in copper with 3/4" mains. Correct?
Let me know what you find at the hose bib and we'll go from there. Good luck, Tom

When I open the hose bib then turn on the shower, the water from the hose bib pretty much stops and the shower will still flow a little.

I'm going to have the city come out again before I call a plumber.

Thank you everyone for helping me solve this mystery.

Sorry, but I think the enclosed article was not written by an experienced plumber.

Let us know if you got better "pressure" after your plumber "....blew your pipes".....
Blew your pipes Sounds kinky to me!