Water Well Problems- The Pressure Switch

If you have a private drinking water well sooner or later you will turn on the faucet and nothing will happen. There are a number of reasons why a well might suddenly stop producing water, but basically they all break down into equipment failure, electrical or power failure, depletion of the aquifer or other groundwater problems and failing well design and construction. There is one other possibility-that your pipes have frozen. First make sure you have power (no power, no water) and that it is not really, really cold. Pressure switch failure is one common cause of loss of water and other well problems, like a loss of pressure.

If you have the common drilled well with an immersion pump in the well and some equipment in the basement, the first thing you should do is go downstairs and take a look. Though I admit that it is hard to differentiate problems just looking at the equipment in the house, sometimes you can.

The components within the basement provide consistent water pressure to the fixtures in the house and turns on the pump to maintain a constant pressure. The pump moves water to the basement water pressure tank, inside the tank is an air bladder that becomes compressed as water is pumped into the tank. The pressure in the tank moves the water through the house pipes so that the pump does not have to run every time you open a faucet. The pressure tank typically maintains the water pressure between 40-60 psi (or sometimes 30-50 psi). The pressure is maintained in this range by a diaphragm-actuated electrical switch with standard contact that makes a connection to turn on the pump when the pressure falls below the lower pressure (the “cut in” pressure) set point and cuts off the power when the upper set point is reached . The set rang is always 20 psi (it can be adjusted slightly) but the actual range is preset when you buy a switch.

After the pressure drops below 40 psi, the diaphragm pops and the electrical contacts touch and the switch turns on the pump and the pressure in the tank increases. When the top pressure is reached the contact is broken. The most common pressure switch is made by Square D of the 9013 series. I think it was designed around 1950 give or take a few years, and can last a fairly long time, but lots of things can go wrong with it.

The pressure switch easily clogs and easily fails in high sediment water. You can buy a new switch for about $20 (installation extra and all the fittings and pressure gauge if you want to replace those could bring the price to about $120 ). If the pressure switch fails the pump will not turn on, or the pump may not turn off or the pump may run erratically. So if you have no water, you might want to do a quick check of your fuses or circuit breakers to make sure that the problem is not electrical. You would be surprised how often a well is struck by lightning or other short occurs in a well system. If the circuit breaker is popped (remember that a well runs on 240 volts and there are generally two switches toggled together) and you can restore water by flipping the switch(s) then you’re done, but sometimes the switch will pop again in a little while and that is typically an electrical problem or a short. Call a well driller.

Next check the pressure gauge on your pressure tank, Read it. If it is not showing a pressure of 40-60 psi (or 30-50 psi) that could be a sign that the pump is not turning on. The question is why. The pump could have failed, the well could be dry or not have enough water to operated (there is a cut off on the pump to protect it when the water level is low), the pressure switch could have failed to pop or the contacts could be corroded. We all hope the problem is the inexpensive and easy to fix pressure switch. First tap the gauge with the back of a screw driver (gently) and see if the gauge moves. The gauge can clog with sediment so can the pressure switch. Also, you might want to carefully take off the cover to the pressure switch-remember there is 240 volts in there and do not touch the contact or better yet cut the power first.

Look at the pressure switch. Do the contact look shinny and clean? If not the switch is likely your problem. You can pick up a new one at both Lowes and Home Depot as well as your rural supply. They are not difficult to change out, but remember to turn off the power and drain the pressure tank before you begin. If you are new to these things you might want to call a professional.

If the pressure is in the desired range (even after you tap the gauge), but you still have no water, it could be several things. The pressure tank could be water logged or you could have a frozen pipe or pipes. If it is not winter, then check the pressure on the pressure tank using a tire pressure gauge. Is it reading on the gauge in agreement with the tank gauge? Drain the water out of the pressure tank . You should hear a ping or if you left the cover off of the pressure switch you should see the diaphragm pop. If the electricity is on the pressure switch if it and the pump are both working should turn on the pump. The pump is the piece of equipment subject to the most wear and tear and often fails.