Key takeaways
A pump that won’t switch off almost always means a leak, a flat pressure tank, or a worn pressure switch.
How the pump behaves points to the cause: short bursts mean a leak, rapid cycling means the tank, non-stop running means the switch.
A simple water-meter test, with the pump and all taps off, shows whether a hidden leak is the cause.
The pressure switch and any wiring are a technician’s job, not a do-it-yourself fix.
What a pump that won’t switch off is telling you
Before calling anyone, watch what the pump does when no one is using water: the pattern points straight to the cause. A pump that will not switch off is holding less pressure than it should, and only three things cause that. The table matches what you see to the likely cause and the check to run.
What the pump is doing | Likely cause | Safe check you can do | Who fixes it |
Runs in short bursts with every tap closed | A leak letting pressure escape | Water-meter leak test; check taps and toilets | You, then a technician for a hidden leak |
Switches on and off every minute or two | The pressure tank has lost its air | Tap the tank; top up the air to spec | You, up to a point |
Runs non-stop, leak and tank ruled out | A worn or mis-set pressure switch | None, it is electrical | A technician |
Cause 1: a leak letting pressure escape
The most common reason a pump keeps running is a leak. The pump holds pressure in the pipes, so if water slips out through a dripping tap, a running toilet, or a leaking pipe, the pressure drops and the pump restarts again and again to top it up. The clearest sign is a pump that runs in short bursts even with every tap closed.
Step 1. Turn off the pump and close every tap and outlet in the house.
Step 2. Read the water meter and note the figures.
Step 3. Wait twenty to thirty minutes without using any water, then read it again. If the meter has moved, water is escaping, and that is why the pump will not rest.
If the meter shows a leak, start with the easy culprits: a dripping tap or a toilet that keeps refilling. Both are simple to fix or replace yourself, and often that is the whole problem. A leak you cannot find, or one inside a wall or underground, is a job for a technician.
Cause 2: the pressure tank has lost its air
If there is no leak, the next suspect is the pressure tank. Most home pumps sit beside a tank with a cushion of air behind a rubber lining; that cushion stores pressure so the pump can rest between uses. When the air leaks away, the tank fills with water and cannot hold pressure, so the pump runs almost constantly or switches on every minute or two.
Tapping the tank is a quick check: the top sounds hollow when there is air behind it, dull when it is full of water. Topping the air back up through the tank’s valve, pump off and system drained, fixes it if the lining is still good. If the air will not hold, the lining has failed and the tank needs a technician.
Cause 3: the pressure switch
With a leak and the tank both ruled out, the cause is usually the pressure switch. This is the small part that senses the pressure in the system and tells the pump when to start and stop; when it wears out or is set wrong, it never sends the signal to stop. A pump that runs non-stop, with no leak and a healthy tank, points here.
The switch is an electrical part wired into the pump, so this is where your checking ends and a technician begins. Adjusting or replacing it is not a safe do-it-yourself job.
When it is a technician’s job
The line between a self-fix and a service call is clear here. Finding a leak, fixing a dripping tap, and topping up the tank’s air are safe to do yourself. A hidden or in-wall leak, a tank that will not hold air, anything to do with the pressure switch or wiring, and installing or replacing the pump are technician jobs, both for safety and because the electrics are easy to get wrong.
If the problem sits on the technician’s side of that line, you can post a water pump repair task on gigit, set your budget, and choose from the offers local gigit heroes send to match it.