Drip only after the pump runs
The area stays mostly dry until water is used and the system builds pressure again.
Start here: Look first at threaded fittings, the pressure gauge, and pipe joints above the tank.
Well pressure system leak
Well Pump Pressure Tank Leaking
Direct answer: A leaking well pump pressure tank is usually either water tracking down from a threaded fitting, pressure gauge, or nearby pipe, or the tank shell itself has rusted through. Start by finding the first wet point, not the lowest drip. If water is coming from the tank body or the air valve area, the tank is usually finished and that is a pro-level replacement.
Most likely: The most common homeowner-find is a small leak at the pressure gauge threads, tank tee fittings, or a pipe joint above the tank that makes the tank look like the source.
Well equipment leaks can fool you because everything below the real leak gets wet. Wipe it down, watch it under pressure, and separate a simple threaded leak from a failed tank shell early. Reality check: if the tank is rusted and sweating from one spot in the steel, no sealant is going to save it. Common wrong move: wrapping tape around a wet fitting without depressurizing the system first.
Don’t start with: Do not start by cranking harder on fittings, opening the pressure switch cover, or buying a new tank before you know whether the leak is actually on the tank or just above it.
If the leak starts on a fitting or gaugeShut power off, relieve pressure, and reseal or replace only that leaking part.
If the leak starts from the tank body or Schrader air valveStop there and plan for professional tank service or replacement.
Last reviewed: 2026-04-06
What the leak looks like
Tank looks wet all the time
The shell is damp or rusty and you cannot tell where the water begins.
Start here: Dry the whole area completely and trace the first wet point with a flashlight and paper towel.
Water at the very bottom seam
The floor is wet under the tank and the shell has rust streaks or bubbling paint.
Start here: Check whether the steel tank body itself is leaking before touching any fittings.
Leak near the air valve
Water appears at or around the Schrader-style air valve on top or side of the tank.
Start here: Treat that as a failed internal bladder or tank problem, not a simple external fitting leak.
Most likely causes
1. Leaking threaded fitting at the tank tee or nearby pipe joint
This is the most common lookalike. Water starts at a joint, then runs down the piping and tank shell until the whole tank seems to be leaking.
Quick check: Dry each joint, then press a dry paper towel around the threads while the pump cycles. The first damp spot usually gives it away.
2. Well pressure gauge leaking
A bad gauge seal or cracked gauge body can seep slowly and drip onto the tank tee and floor.
Quick check: Look for moisture forming right at the gauge threads or behind the gauge face after the system pressurizes.
3. Pressure tank shell rusted through
Older steel tanks often fail at a rust pit, lower sidewall, or bottom seam. The leak usually returns immediately after drying.
Quick check: If water beads directly out of the steel shell and not from a fitting above it, the tank itself is done.
4. Failed pressure tank bladder showing up at the air valve
If water comes from the air valve, the internal bladder has ruptured and the tank is no longer separating air from water correctly.
Quick check: Do not depress the valve casually, but if the valve cap area is already wet with water, that strongly points to tank failure.
Step-by-step fix
Step 1: Shut the system down and find the first wet point
You need a clean starting point. On well equipment, the lowest drip is often not the real leak.
- Turn off power to the well pump at the breaker or disconnect.
- If you have a shutoff valve feeding the house after the tank, close it if needed to limit cycling while you inspect.
- Wipe the tank, fittings, gauge, and nearby piping completely dry with rags.
- Place a dry towel or shallow pan under the area so new drips are easier to spot.
- Use a flashlight and watch the system for a few minutes without touching fittings yet.
Next move: You can now see whether the leak starts on a fitting, the gauge, the air valve area, or the steel tank body. If everything is soaked again immediately and you still cannot isolate the source, the leak is active enough that a pro should trace it before water damage spreads.
What to conclude: A clear first wet point keeps you from replacing the wrong part or blaming the tank for a pipe leak above it.
Stop if:
- You see arcing, burnt wiring, or water reaching electrical components.
- The floor is flooding faster than you can contain it.
- The tank or piping is badly corroded and looks ready to break if disturbed.
Step 2: Separate a fitting or gauge leak from a tank-body leak
Most repairable DIY cases are at threaded connections, not the tank shell itself.
- Look closely at the pressure gauge threads, the tank tee, elbows, unions, and any pipe joint directly above the tank.
- Wrap a dry paper towel around one suspect joint at a time and wait for the system to pressurize.
- Check whether water forms at the gauge threads or behind the gauge face.
- Inspect the steel shell, especially the lower half and bottom seam, for a pinpoint bead forming directly out of the metal.
Next move: If one fitting or the gauge gets wet first while the tank shell stays dry, you likely have a localized external leak. If the steel shell itself beads water or the bottom seam keeps weeping with no wet fitting above it, the tank has failed.
What to conclude: A leaking fitting can sometimes be repaired. A leaking pressure tank shell is replacement territory.
Step 3: Check the air valve area without creating a bigger problem
Water at the air valve points to an internal tank failure, and that changes the plan fast.
- Locate the Schrader-style air valve on the pressure tank.
- Look for moisture under the valve cap or rust trails coming from that opening.
- Do not remove the valve core or press the stem unless you already know the system is depressurized and you are intentionally testing the tank.
- Listen for rapid pump cycling or short bursts from the pump if someone briefly uses water elsewhere in the house.
Next move: If the air valve area is wet with water, or the pump short-cycles along with the leak, the pressure tank is likely failed internally. If the air valve area is dry and the leak is still at a threaded connection, stay on the external leak path.
Step 4: Repair only a confirmed external gauge leak
A leaking gauge is one of the few well-tank-area leaks that is often straightforward once the source is confirmed.
- Leave power off to the pump.
- Open a nearby faucet to relieve system pressure until flow slows and pressure drops off.
- If the gauge is the confirmed first wet point, remove it carefully with the correct wrench support so you do not twist the tank tee or connected piping.
- Install a matching well pressure gauge with thread sealant appropriate for potable water threaded connections.
- Restore pressure and watch the gauge threads closely for fresh seepage.
Next move: If the new gauge stays dry through a full pump cycle, the leak was the gauge and you are done. If the leak remains at the tee, another threaded joint is leaking or the assembly is too corroded for a simple gauge swap.
Step 5: If the tank shell or air valve is leaking, stop patching and schedule tank service
Once the tank itself has failed, patch attempts are temporary at best and often make the final replacement messier.
- Keep power to the pump off if the leak is active enough to cause repeated cycling or ongoing water loss.
- Use house water sparingly until the system is evaluated, or shut the supply side down if leakage is severe.
- Take clear photos of the leak point, tank label, and surrounding piping so a pro can bring the right replacement setup.
- If your symptoms also include pressure swings, short cycling, or loss of pressure, review the related pressure-tank problem pages before the service visit so you can describe the behavior clearly.
- Book a well or plumbing pro for pressure tank replacement or full tank-tee service.
A good result: You avoid wasting time on sealants and get the system repaired at the actual failure point.
If not: If the leak worsens, the pump will not stop running, or you lose water service, shut the system down and treat it as an urgent well-system call.
What to conclude: A leaking tank body or wet air valve means the tank has reached end of life or has an internal failure that is not a basic DIY repair.
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FAQ
Can a leaking well pressure tank be repaired?
A leak at the pressure gauge or another external threaded fitting sometimes can. A leak from the steel tank body, bottom seam, or air valve area usually means the tank itself has failed and needs professional replacement.
How do I tell if the tank is leaking or just a fitting above it?
Dry everything first, then watch for the first wet point while the system is under pressure. If a joint or gauge gets wet first and water runs down the tank, the tank may be fine. If water beads directly out of the steel shell, the tank is the source.
What does water at the air valve mean on a pressure tank?
That usually points to an internal bladder failure or another internal tank problem. It is not a normal external leak and it is not something to fix with thread sealant.
Is it safe to keep using water if the pressure tank is leaking?
Only for a minor confirmed fitting seep, and even then you should monitor it closely. If the tank shell is leaking, the pump is short-cycling, or water is reaching electrical parts, shut the system down and call for service.
Should I replace the pressure switch too if the tank area is leaking?
Not just because the area is wet. Pressure switches and other well controls are fitment-sensitive and should only be replaced after a clear diagnosis. First find the actual leak source and keep water away from the controls.
Why is the floor wet under the tank but I cannot find a leak on the tank?
Water often travels down pipes, fittings, and the tank shell before it drips to the floor. The real source may be a small leak at the gauge, a threaded joint, or a pipe above the tank.