Do this first
- Walk the house and run four fixtures. Kitchen, a bathroom sink, the tub, and an outside spigot. Weak at all four is the well side. Weak at one is that fixture.
- Change the sediment filter cartridge. It's the cheapest cause and the one people skip. If you can't remember the last time you changed it, that's your answer more often than not.
- Find the gauge on the pressure tank and write down what it reads right now, then watch it while somebody runs a shower. You want the number, and you want to know whether it climbs, falls, or sits still.
- Check that nothing is half closed. If anyone worked on the water heater, the boiler or the well in the last year, a valve may have been left partly shut.
- If the pressure fades after twenty minutes of use and comes back an hour later, stop drawing water. That's the well drawing down, and running it dry damages the pump.
- Call 973-853-1550 with the gauge numbers. Knowing whether the needle reaches cut-out tells us most of what we need before we pull into the driveway.
Is it every faucet or just one?
Settle this first, because it splits the problem into two completely different jobs. Walk the house and open things up. Kitchen sink, a bathroom sink, the tub, an outside spigot. If every one of them is weak, the trouble is upstream of your house plumbing: the well, the pump, the tank, the switch, or a filter. If one is weak and the rest are strong, the trouble is at that fixture and the well is fine.
A single weak fixture is nearly always a packed aerator or a supply valve under the sink that got bumped. Unscrew the aerator off the end of the spout and look at the screen. On well water it fills with sand grains and rust flake and chokes a full stream down to a dribble. Soak it in vinegar, rinse it, thread it back on. Shower heads do the same thing and clean the same way.
One more split worth making. If the cold side is strong everywhere and only the hot side is weak, that's the water heater or the valve on top of it, not the well. Sediment settles in the bottom of a tank heater and scale narrows the nipples at the inlet and outlet.
Weak everywhere means keep reading, and the order you check things in matters, because the cheapest and most common cause sits right at the front of the list.
Change the sediment filter before you do anything else
The big blue canister on the line coming out of the pressure tank holds a cartridge that costs eight to twenty dollars. A plugged one strangles the whole house, and it's the single most missed cause of low pressure on a well. We get called out, change a cartridge, and the shower comes back. Save yourself the service call and check it first.
Here's the tell that makes it obvious. If the gauge on the pressure tank reads a healthy 50 psi while the shower upstairs runs at a trickle, the restriction is downstream of that gauge. The filter is the first thing downstream of that gauge. Shut the water off, unscrew the housing with the plastic wrench that came with it, and look at the cartridge. A spent one is tan, orange or gray all the way through instead of white.
Most well water here needs a cartridge every three to six months. If yours turns orange in three weeks, the filter is doing its job but it's also telling you something about the water. Iron that heavy is worth testing and worth treating at the source, because a filter is a strainer, not a fix.
What the gauge should actually be doing
Your pump doesn't run continuously. A pressure switch turns it on at a low number and off at a high number, and those two numbers are the cut-in and the cut-out. The two common settings are 30/50 and 40/60. On a 30/50 system the pump starts when house pressure drops to 30 psi and stops when it builds to 50. On 40/60 it starts at 40 and stops at 60.
Watch a full cycle instead of glancing at the needle once. Open an outside spigot and let it run. The needle should fall smoothly to the cut-in number, the pump should audibly start, and the needle should then climb steadily and reach cut-out within a minute or two of the spigot being closed. Three things go wrong with that picture. The needle climbs but stalls out at 42 and never reaches 50, which means the pump can no longer make the pressure it's asked for. The needle bounces up and down every few seconds, which is short cycling and points at the tank. Or the needle sits pinned at 50 while your fixtures run weak, which means the restriction is between the gauge and the faucet.
If your system is set to 30/50 and everything else checks out healthy, moving it to 40/60 makes a real difference in the shower. It's not free of consequences. The pump has to be capable of building 60 psi, the tank's air charge has to be raised to match, and old plumbing that was leak-free at 50 sometimes starts weeping at 60. Adjusting the switch takes minutes for someone who has done it. Doing it wrong burns out a pump that's already struggling to reach 50, so it's not the place to start.
A pressure tank that's lost its air
The tank next to your pump controls is not a water storage jug. It's a spring. Inside a modern tank a rubber bladder separates a cushion of compressed air from the water, and that air is what pushes water into your house between pump cycles. Factory precharge is set 2 psi below cut-in, so 28 psi on a 30/50 system and 38 psi on 40/60.
When the bladder tears or the air charge bleeds off, the tank fills solid with water. That's waterlogged. You lose the cushion, so the pump kicks on and off every few seconds instead of every few minutes, and your shower goes strong, weak, strong, weak on that same rhythm. People describe it as pressure that surges rather than pressure that's low, but at the fixture it feels like both.
You can test it yourself. Knock on the side of the tank from the bottom up. The lower part where water sits sounds dull and solid, the upper part where air sits sounds hollow. A tank that sounds solid all the way to the top is full of water. To check the charge properly, shut the pump breaker off, open a faucet and drain the pressure to zero, then put a tire gauge on the air valve on top of the tank. You should read 28 or 38 depending on your settings. A reading of zero with water spitting out of that valve means the bladder is done and the tank gets replaced.
Tank replacement is a same-day job in most basements, and size and how the piping was built decide the number. Older tanks with no bladder at all, the plain galvanized kind still in plenty of basements around here, lose their air constantly and need an air volume control that works.
Half closed valves and pipe that's closing itself
Any time somebody worked on your water, a valve got turned. New water heater, new boiler, a leak repair, a well service call, a water softener install. Valves get shut to isolate the work and then opened again by feel rather than by count. A gate valve, the kind with a round handle you spin, can be left three quarters closed and still look open. It'll pass enough water to fool you and cost you half your flow.
Trace your line and put hands on every valve. The one at the well line where it enters the basement, the one on the tank tee, the whole house shutoff, and any valve feeding a treatment unit. Ball valves with a lever should sit parallel with the pipe when fully open. Round handles get spun all the way counterclockwise, then backed off a quarter turn. This costs nothing to check and we find it more often than you'd guess.
Then there's the pipe itself. Galvanized steel supply lines from the 1950s and 60s corrode from the inside, and on well water carrying iron and manganese the buildup is scale that grows year after year. A three quarter inch line can end up with the opening of a pencil. The symptom is distinctive: pressure looks fine at the gauge, the first fixture off the main runs decent, and the far end of the house or the upstairs bath is miserable, and it gets dramatically worse the second somebody else turns on a tap.
You can't clean that out in any lasting way. The fix is repiping the runs that are choked, and it's often a handful of accessible runs rather than the whole house. Iron bacteria does the same narrowing trick inside the drop pipe down the well and on the pump intake screen, which puts the restriction 300 feet down instead of in your basement.
When it's the pump, and the order to work through
A submersible pump doesn't quit all at once. It loses capacity. The impellers wear, sand grinds the clearances open, and the pump that used to fill the tank in ninety seconds starts taking four minutes, then six, then never gets to cut-out at all. If you're watching the gauge stall out at 42 psi on a 30/50 switch and the tank is healthy and the filter is new, that's a pump at the end of its working life. Most pumps in our area go eight to fifteen years.
A check valve does the opposite kind of damage. There's one at the pump and sometimes one more up the line, and it's a one way door that keeps water from falling back down the well. When one sticks partly closed it becomes a restriction the pump has to fight through, so you get low flow with a pump that sounds like it's working hard. When one sticks open you get water hammer and rapid cycling instead. Either way the pump comes out of the well to fix it.
Drawdown is the last one and it looks different from all of these. Pressure is fine first thing in the morning. Twenty minutes into laundry and showers it fades, and the faucets start spitting air. An hour or two with the water off and it's back to normal. That isn't the pump failing, that's the well running out ahead of the pump, which is common on fractured rock wells. Running a pump into a dry well is what turns a yield problem into a pump replacement, so shut the breaker off and let it recover.
The order that saves you money: change the sediment filter, watch the gauge through a full cycle and write down the two numbers, confirm whether it's one fixture or all of them, put hands on every valve. Four things, an hour of your time, no tools you don't own. If pressure is still low after all four, the answer is inside the tank or down the well, and that's the call. Reach us at 973-853-1550 and lead with the gauge numbers and whether the needle reaches cut-out. That one detail tells us more than any other thing you can say.