Water pressure issues have stumped my plumber

[donie1]

Hello everyone.

I am having a water pressure issue and the search I did on the forums doesn’t really cover my issue.

When I turn on a faucet, I have decent water pressure; however, if another faucet is turned on I lose water pressure at both. If I am upstairs taking a shower and someone turns on the faucet to rinse a dish, I can tell when it is turned on and when it is turned off. If a toilet is flushed water pressure at the faucet drops to practically nothing.

I have had a plumber out to try to figure out what is going on. He looked at the plumbing in the house and said everything looked like it should. He put a water pressure gauge on the outside faucet and it showed 100+ psi. After seeing the dramatic drop in water pressure when a faucet is on and the toilet is flushed, he though his gauge was broken and bought a new one. The new gauge also showed 100+ psi.

His thought is since the psi is greater than 80psi and there isn’t a pressure reducing valve, the high pressure might be causing something to not working right and his suggestion is to install the valve. To his credit, from the beginning he told he wasn’t very experienced in this area he wasn’t really sure what to do and hasn’t charged me for this yet. He urged me to call in another plumber for a second opinion to see if they could figure it out before installing the pressure reducing valve.

Before I called in another plumber for a second opinion, I wanted to reach out to anyone here to see if his thought process and solution makes sense or if anyone might have an idea of what is going on.

I know this was a long read, so if you made it this far, thank you.

Can anyone help me out?

 

[Twowaxhack]

Sounds like you have plenty of pressure but your volume is reduced.

This is caused by a restriction in the piping at some point. A valve could be partially closed, the water meter itself may be defective, etc, etc.

You have a flow restriction at some point. Start at the water meter and work your way to where the water enters the home.

 

[ReelPlumber]

Has this always been happening or something that recently started?

Check the type of shut main off valve or valves that are on the house. If globe or non full port ball valves have been used that can cause volume problems. It sounds like you have plenty of pressure and the problem is volume.

Also if you have a backflow device at the meter it may be sticking and causing the flow restriction.

As Twowaxhack stated start with the simple things at the meter. Make sure the curb stop at the meter is open all the way. If there is a backflow with valves on it make sure they are opened all the way. Make sure all the valves on the service at the house are open all the way.

Has there been any repairs to the city/county water mains in the area? I have seen where there was a break in a main and while being repaired some debris/trash had entered they system. Once the debris reached a small enough pipe it caused a partial blockage creating a loss of water volume to the upstream system.

BTW....Once you figure out the flow problem I would definitely look into a pressure reducing valve. Your plumbing and appliances would appreciate it.

 

[RS]

When that happens at our house it's time to change the filter, but I only need to do that a couple of times a year.

 

[CT18]

What are the numbers it is dropping down too

 

[donie1]

Thank you everyone for the responses.

@ReelPlumber. We have had this issue since we bought the house. The house was built in 1985 and we bought it in 2016. Originally, I would turn on the kitchen faucet and would get high water pressure that dropped a few seconds later. If another faucet was turned on all running water would slow down. The water company replaced our water meter and the problem changed. I still have the water flow problem, but when the water turns on it is no longer a sudden rush that slows down.

I will check the water meter and see if there is anything there.

@ CT18. I am not sure what the pressure drops to because we didn’t turn on the faucet when the gauge was attached. I think I will go buy one this weekend and see if the pressure drops when a faucet is turned on.

 

[TomFOhio]

What size is your main water line in the house??