Well Pumps: How They Work, Problems & Replacement
Well water pumps come in two main kinds: a submersible that hangs down inside the well casing, or a jet pump that sits above ground and pulls water up by suction. Either one fills a pressure tank, and a pressure switch turns the pump on and off as the tank pressure rises and falls. When the water stops, the pump is often fine and the fault is the switch, the tank, the control box or the breaker.
Which pump do you have?
- Submersible. Nothing visible but a wellhead and maybe a control box on the wall. Forbes puts a four-inch submersible in wells roughly 110 to 400 feet deep. Start with submersible well pumps.
- Shallow well jet pump. A motor and pump body next to the tank in the basement or a pump house, for wells 25 feet deep or less. See jet pump problems and repair.
- Deep well jet pump. Same look, but with two pipes going into the well. Forbes says these can reach about 100 feet.
- Hand, solar and constant pressure pumps. Backup or specialty setups: hand pumps for wells, solar well pumps and constant pressure systems.
The most common well pump problems
If you have no water or weak water, go through these first:
- No water from the well
- Low water pressure
- Pump keeps running
- Pump short cycling
- Breaker keeps tripping
- Air in the water lines
- Signs of a bad well pump
- Well pump not working
On three-wire submersibles, the starting parts live in a box on the wall, and a failed capacitor there can look like a dead pump. That's covered in control box and capacitor problems. Jet pumps that lost their water need priming.
Repair or replace
HomeGuide puts typical well pump repair at $300 to $600, and full replacement at $1,000 to $2,500 or more. Its rule of thumb is to replace a pump that's 10 to 15 years old and has needed several repairs, and to repair a newer pump with a single failed part.
- Well pump repair
- Well pump replacement
- Well pump replacement cost
- Sizing a well pump
- How long well pumps last
If the power goes out often, the pump is the first thing you lose. See backup power for a well pump.
FAQ
Will turning off the well pump stop the water?
Not right away. The pressure tank keeps feeding the house until its pressure drops to the switch's cut-in point. After that, nothing flows until the pump is back on.
Where is a well pump located?
A submersible sits down in the well, usually below the water line, so you'll only see the wellhead outside. A jet pump sits above ground, usually beside the pressure tank in a basement, crawlspace or pump house.
Can a well pump last 30 years?
It's rare. HomeGuide puts the average at 8 to 15 years, with submersibles usually outlasting jet pumps. Forbes says a submersible can last up to 25 years.
How do you troubleshoot a well pump?
Start with the breaker, then the pressure gauge and pressure switch, then the tank's air charge. Those three account for a lot of no-water calls before anyone needs to pull the pump. The well pump not working guide lays out the order.
All guides in this section
Fix it
How-to
Cost
Buy
Learn
Sources
- HomeGuideHow Much Does a Well Pump Cost To Replace or Install? (opens in a new tab)
- HomeGuideHow Much Does Well Pump Repair Cost? (opens in a new tab)
- Forbes Home4 Major Types of Well Pumps You Should Know (opens in a new tab)
- Franklin Electric (copy hosted by Nebraska DWEE)Application, Installation, Maintenance (AIM) Manual: Submersible Systems, 60 Hz (opens in a new tab)
- AngiHow to Set Up a Well Pump and Pressure Tank (opens in a new tab)