Water Pressure

Is there an accepted method to test for proper water pressure at the fixtures. What do others do?
Putting a guage on the hose bib will tell you what the pressure is in the main but it won’t tell you if the curb valve is partially closed.

A partially closed valve will not effect static pressure, it will only effect volume. I usually check pressure at the water heater (many will advise against that), because the pressure at the heater will be (should be) the same as the house-fixtures and appliances.

I would advice against but only because of the high probability it would leak afterward because of the high calcium content in our water(especially well water) the valve often gets sediment in it ans will not seal.

I carry caps for that eventuality. . .

But volume (ie flow) is what people care about. I agree that a pressure test at the hose bib or water heater only tells you the static pressure and will not indicate a partially closed curb valve.


Run the sink, run the tub and while they are flowing flush the toilet and observe any changes in flow rate.

It’s called functional flow.

Report what you observe and move on.

Bingo. :smiley:

I don’t check the pressure unless I see issues while running the entire bathroom, which is rare.

David, the first 2 years I was in business, I never tested pressure either unless I suspected a problem. I now test every home and about 40% of them are either too high or too low in pressure. Most of those cases are excessive pressure.

Functional flow often seems OK even with 30 psi water pressure. You actually usually get very good functional flow with 120 psi water pressure! A pressure test on every home would be a wise thing to do in my opinion. If there is a plumbing failure due to excessive water pressure, guess who will get a call?

Over 3,000 inspections performed with no pressure tests and I’m still waiting for that call.

Another “component assessment”?

Only functional flow “observations” required here.

There are other observations that indicate excessive pressure, at which time I test.

I would test pressure more but I can’t seem to keep a calibrated gauge around. They freeze, get dropped, dropped on in the tool bag…

High pressure and compression fittings and plastic pipe don’t go well together.

Pressure Regulating valves fail quite often. Who’s to prove the pressure at the time of inspection?

A partial closed valve is only a problem when the “functional flow” test fails.

Mr. Pope, why don’t you like to use hose bibs?
I like to keep the water leaks outside the house.
I am also gun shy around those blow down valves on the water heater. Most here are plastic, and don’t do well over time when associated with heat.

Many times, the hose bibs are not regulated. The water heater is part of the “house” system and will reflect the same pressure that will be found at all interior fixtures and appliances.

Good judgement should always be used. If the heater is old, or if there are indications that there will be any problem, I will look for an alternate source.

Seems like all the more reason to test the hose bibs. Wouldn’t you want to know if that part of the system is excessively high? There are fittings there too that are subject to failure.

The NACHI standard states: “Inspect and report as in need of repair deficiencies in the water supply by viewing the functional flow in two fixtures operated simultaneously.”

Isn’t anything beyond visual (use of pressure guage) increasing your risk when you go beyond visual and reporting your observation?

Many times, hose bibs are not part of the house system. Separate piping is often installed for irrigation and other uses. Only the house/building supply requires regulation if the pressure exceeds 80 psi. There is no such requirement for piping outside of the building/house.

[quote=“jfunderburk, post:9, topic:38792”]

David, the first 2 years I was in business, I never tested pressure either unless I suspected a problem. I now test every home and about 40% of them are either too high or too low in pressure. Most of those cases are excessive pressure.


First question, what do you consider an acceptable pressure range.
Secondly, water percentage of homes on city water do you find outside of that range.

Above 80 psi is too high. Probably 25% of the homes I inspect have excessive pressure, and in my area the street pressure is usually well over 120 psi - I’ve seen it as high as 160 psi.

Anything less than 15 psi requires a pump or other means to increase pressure.

In my area, most hose bib’s are part of the homes potable water system. If a regulator is installed its at the interior main water shut off valve with the supply drops branching off of it to water closets, kitchen, hose bibs, etc.

Many residences out here have “sub meters” (a secondary water meter) for their irrigation systems. Water used for irrigation is billed at a lower rate because they do not include a “sewer” charge.

I might see about 5% to 10% here with high pressure. You pretty much know which neighborhoods they are after a while. Always the homes in the foothills where the water tanks are higher than the houses.:smiley: