How much should home water pressure change when water is being consumed at one or more outlets?

The standard water pressure at our outside hose bibs is 40 PSI (city of Houston). I wondered if that might be a little low, but my neighbor's is the same.

However, the pressure drops more than I expected if water is being used somewhere. For example, today I had a small sprinkler running on a hose outside, and a bathtub was filling inside, and the pressure at the outdoor hose bib was 20 PSI.

That seems like a big % drop to me. Is that normal, and if not, what might cause that behavior?

You have a volume issue, most likely. Pressure should not drop that much. Do you have galvanized pipes or what age is your plumbing system?

Is your meter all the way open?

Pipes inside have all been replaced with PEX in the last few years. Before that, they were all galvanized. The pipe from the meter to the house is still old/original (1960s).

I believe so but will double check tomorrow.

This is likely your problem. Only way to know is to check pressure and volume at the meter and the house.

Fill up a five gallon bucket at meter and house and see what is the result. Only issue is you likely do not have a hose bibb at the meter and line is probably galvanized pipe that is corroded and has blockage.

Your yard line is probably not that long of a run to replace.

Is there a pressure reducing valve installed after the meter ? Will look like this, usually under a cover in a box



https://www.lowes.com/pd/Watts-3-4-in-Brass-Female-In-Line-Water-Pressure-Valve/1001331056

What is normal
http://rb.gy/mb61l

Pressure/volume reducers
1. SOP Aggieland is a 3/4" meter near the street/alley; anything bigger costs $$$$$$ and may change rates charged you
2. SOP supply line from meter 3/4" but if this run is long, should be bigger, e.g. 100 yards = 1.25" PVC (even with a 3/4" meter will allow fixtures normal pressure/volume)
3. Neighbors using excessive water, e.g. sprinkler systems, filling swimming pools, even soaker tubs
4. Leak - OH NO!!!
5. NOT getting a 3/4" supply line to at least M.Bath as per architect specs (1/2" SOP everywhere)
6. Pressure reducing/balancing valves - can be found most anywhere these days
7. Extra long PEX line runs .... yes, even smooth pipe "friction" over distance takes a toll on pressure/volume (see above) More comonly found in retrofits than in new builds

Let us learn from what the real answer turns out to be?

The city valve is fully open, and I don't see anything that looks like a pressure limiting device. Below is a link to a pic of the box (couldn't figure out how to get the pic to embed).

Honestly not sure what the gate valve is on the right side. I used to think that was the city valve, but when I messed with it years ago, it didn't seem to do anything. Maybe an old city valve?

The distance from the meter to where the water line enters the house is 35-40 feet. What is a ballpark price to have a plumber replace that old pipe? I've heard others recommend DIY digging to avoid paying plumber rates to dig.

https://imgur.com/a/wZ44Rus

$50 ft with digging and plumbing

If you want call one of these guys

will delete numbers soon

karmapoliceman said:

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The city valve is fully open, and I don't see anything that looks like a pressure limiting device. Below is a link to a pic of the box (couldn't figure out how to get the pic to embed).

Honestly not sure what the gate valve is on the right side. I used to think that was the city valve, but when I messed with it years ago, it didn't seem to do anything. Maybe an old city valve?

The distance from the meter to where the water line enters the house is 35-40 feet. What is a ballpark price to have a plumber replace that old pipe? I've heard others recommend DIY digging to avoid paying plumber rates to dig.

https://imgur.com/a/wZ44Rus

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I had an emergency replacement done on mine and it cost me $1200.

JP76 said:

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Is there a pressure reducing valve installed after the meter ? Will look like this, usually under a cover in a box



https://www.lowes.com/pd/Watts-3-4-in-Brass-Female-In-Line-Water-Pressure-Valve/1001331056

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It's almost always this valve

Check at different times of day. Middle of the night.

Whole city is taking showers and running sprinklers in the morning. With the drought, cities probably have 100s of broken water mains. Pressure in my house has been down since the drought started. Same thing happend last drought.

Best solution is a pump added to your house so that the pressure is always the same. Easy to do.