One tap, or the whole house?
The first question narrows everything. Run the kitchen sink, a bathroom sink, a shower and an outdoor spigot one after another. If only one is weak, the cause is local to that fixture. If every tap is weak, the cause is upstream.
Also compare hot to cold. When the cold side is strong and the hot side is weak, the trouble is usually in the water heater or its piping. When both are weak at every fixture, look at the main line, the main shutoff valve and the regulator.
Symptom, likely cause and who fixes it
Use this table to match what you see to the most likely source. It is a starting point, and a plumber confirms the actual cause.
| What you notice | Likely cause | Who handles it |
|---|---|---|
| One faucet is weak, others are fine | Clogged aerator or worn cartridge | You can clean the aerator, or a plumber can handle faucet repair |
| Hot water weak, cold water strong | Sediment or a partly closed valve at the water heater | A plumber, see water heater repair |
| Whole house weak, started suddenly | Partly closed main valve, failed regulator, or a leak | Check the main valve, then call a plumber |
| Whole house weak, got worse over months | Narrowing pipes from mineral scale or corrosion | A plumber, possibly repiping |
| Pressure low and the meter spins with everything off | A leak on the line | Leak detection |
| Pressure low only at times, neighbors affected too | A utility-side issue | Village Public Works, then a plumber if it is only your house |
If the table points to the street side, you do not have a fixture problem, and a new faucet will not help.
Testing your pressure at home
A pressure gauge is a small tool that screws onto a hose bib. It turns a hunch into a number, and it is the single most useful check.
What to do
- Turn everything off.Shut off dishwashers, washing machines and sprinklers so nothing is drawing water.
- Attach the gauge to an outdoor hose bib.Screw it on hand-tight and open the tap fully.
- Read the number.EPA WaterSense gives 45 to 60 psi as the target range for incoming pressure.
- Interpret it.Much below 45 psi, look for a leak or a restriction. Above 80 psi, codes call for a pressure-regulating valve, and a pro should adjust or install one.
- Test again at a different hour.A reading that drops sharply at busy times can point to the supply rather than the house.
High pressure is not harmless. EPA notes that it can damage piping, fixtures and appliances, raise water use and increase leak risk.
Village main and meter, or your own service line?
Buffalo Grove buys Lake Michigan water from the Northwest Water Commission and distributes it through about 181 miles of village main and four pumping stations. The village owns the main and the meter. The homeowner owns the service line from the curb stop area to the house.
That split matters for who you call. If several houses on your street have weak water at the same time, the cause may be on the village side, and a call to Public Works at 847-459-2545 during business hours is a reasonable first move. If your neighbors are fine and you are not, the problem is more likely on your private side or inside the house.
A partly corroded or damaged service line can cut flow without leaking visibly. A plumber can inspect it, and when the line has to be repaired or replaced, the work falls under water service line repair. The village requires permit steps for service repairs, including 48 hours' notice for the underground inspection, and JULIE must locate utilities at least 3 days before anyone digs.
Not sure whether it is the street or your pipes?
Call (847) 281-8626 and a plumber can help you decide what to check first.
Low pressure that is really something else
A shower that dribbles is not always a pressure problem. Mineral scale on a showerhead can choke the spray while the rest of the house is fine. A quick soak in vinegar often shows whether the head was the culprit.
Water that is moderately hard to hard can also leave deposits. The village's 2022 water quality report lists hardness between 120 and 130 mg/L as CaCO3, which sits at the edge of the moderately hard and hard classes in the USGS scale. USGS notes that heated hard water forms deposits that can narrow pipes and reduce flow, so older hot water lines are the first place to suspect buildup.
Valves that look open and are not
A main shutoff or meter valve that was turned only part way after a repair will restrict the whole house. Check that the main valve handle is fully open. Check the valve at the water heater too.
Pressure regulators
A regulator that fails can swing pressure too low or too high. If your gauge shows a number above 80 psi or far below 45 psi, the regulator is a prime suspect. A plumber can test it and replace it if needed.
What to do if low pressure comes with signs of a leak
Low pressure plus any of the signs below can mean water is escaping somewhere you cannot see.
Treat these as urgent
- The water meter keeps moving when every fixture is off
- A damp patch on a floor, a warm spot on a slab, or a musty smell
- Water bills that have risen without a change in use
- The sound of running water in a quiet house
Close the main valve if you see water, and call the 24/7 line at (847) 281-8626. Hidden leaks are found with leak detection equipment that listens to the pipe and traces the break.
When DIY ends and a plumber should step in
Cleaning an aerator, checking a valve handle and reading a gauge are all fair homeowner tasks. Cutting into pipe, resetting a regulator, or touching anything between the street and the main shutoff is not.
Old galvanized or heavily scaled lines may be restricted from the inside. In that case a larger conversation about replacement pipe makes sense, and a plumber can explain the options and the price before the work starts. A new fixture installation is another call that falls under plumbing installation if the existing supply cannot support it.
What went into this guide
The pressure targets, the 80 psi regulator threshold, and the effects of high pressure come from EPA WaterSense. The hardness classes and the effect of deposits on pipes come from USGS. The village main, meter and service line split and the permit steps come from Buffalo Grove's own pages.
Plumbers in Illinois are licensed by the Illinois Department of Public Health under the Illinois Plumbing License Law, and the IDPH online verification page lets you look up any license before you hire.
The 45 to 60 psi target and the regulator threshold come from EPA WaterSense guidelines, which serve as the standards behind the pressure advice here.
Local note
What Buffalo Grove homeowners should know
Your supply comes from Lake Michigan through the Northwest Water Commission and village mains. Ask Public Works for the latest water quality report if you want to see current hardness and chlorine numbers, and test your own tap if you are curious.
Nearby communities such as Arlington Heights and Wheeling share the same Northwest Water Commission source, so a street-wide pressure change is worth checking with your water department before assuming the fault is inside your home.
Questions we hear from homeowners
EPA WaterSense gives 45 to 60 psi as the target for incoming pressure. Codes call for a pressure-regulating valve when pressure rises above 80 psi.
Screw a pressure gauge onto an outdoor hose bib, make sure nothing else is using water, and open the tap. The gauge shows the static pressure in psi.
Mineral scale on the showerhead or a restrictor is the most common cause. Soak the head in vinegar, rinse it, and see whether the spray recovers.
Yes. A hidden leak diverts water before it reaches the fixtures. If the meter moves with everything off, call a plumber.
Call Village Public Works at 847-459-2545 during business hours. The village owns the mains and the meter. If only your house is affected, call a plumber.
The homeowner owns the service line and the private curb stop side. The village owns the main and the meter.
Yes. The line at (847) 281-8626 is answered around the clock, and a plumber can help you decide whether the issue can wait.