We are on city water. When we are using only one source (sink, shower, etc.) our water pressure/flow is fine. As soon as another source is turned on the water pressure/flow drops considerably. I have seen this before, and of course it makes sense that when you are using more water there will be less of it available to each source, but I've never seen the drop be so considerable. Is this just something we have to live with, or is there something I can change that might be causing it?

You don't have any whole house filters like a sediment filter on your system? If so, change the cartridge. But that would have decreased pressure across the whole house...

If not, wait for an expert, thatd be tom (speedball) to reply.

I do not think we have any filters on our system. We bought the house about a year ago (it's our first house), however, so there are probably many things that I don't know.

Well, I didn't read your post carefully enough.

You say your overall pressure is fine when one faucet is on. If you had a whole house sediment filter that needed changed, the overall water pressure would be lower... the filter would be in a unit near the water meter, often in the basement toward the front of the house where water enters from the street. But that's not your problem.

I'm sure tom will have some questions for you and some advice.

We are on city water. When we are using only one source (sink, shower, ect.) our water pressure/flow is fine. As soon as another source is turned on the water pressure/flow drops considerably. I have seen this before, and of course it makes sense that when you are using more water there will be less of it available to each source, but I've never seen the drop be so considerable. Is this just something we have to live with, or is there something I can change that might be causing it?


This is not a question of pressure buta question of volume. What material are your pipes made of? Plastic? Copper? Galvanized? My guess is that you have a older house with galvanized piping.
Please confirm the above and I'll get back to you ASAP. N Tom

The house was built in 1973. I have had to repair some of the pipe between the main and the house and it was plastic pipe. As far as the piping in the house goes, I think it is plastic, but the base pipes are all in the foundation slab (slab on grade) and can't be accessed or changed.

"As far as the piping in the house goes, I think it is plastic, but the base pipes are all in the foundation slab (slab on grade) and can't be accessed or changed."

I don't think so. Go back and see what's coming out of the wall as stubouts and tell me what the material is. Until I know for sure I can't answer. Regards, Tom

I checked and you are right. The pipes appear to be copper.

As have said," This is not a question of pressure but a question of volume."
If you had galvanized pipes I would have said that the pipes had built up minerals ,(rust) in the pipe walls and are now cutting down on the volume.
However copper pipes aren't bothered as much as galvanized so I'm going to have to look elsewhere.
This will be a process of elimation starting with the first fixture closest to where the water service enters your house system. It could even be a outside hose bib. Let's say it is a outside hose bib that's closest to the water service. Open it up. Full steam? Now open up another faucet. Pressure still OK? Move on to the next closest faucet and do the same thing. At some point you will loose pressure. That's your problem spot. Let me know what you find. Good luck, Tom