masterplumber.netthe logo

All you need to know about the well pump pressure switch.

Well Pump Pressure Switch

The well pump pressure switch, is the control that turns your well pump on and off, For residential pumps the pressure switch comes with 3 factory settings, 20 to 40 PSI 30 to 50 PSI and 40 to 60 PSI. The low number is set for the pump to come on and the higher number is for the pump to turn off, so a 20/40 pressure switch will cause the pump to come on when the pressure in the well tank drops to 20 PSI, then the pump will run until the pressure in the well tank reaches 40 PSI. All of the above pressure switches can be adjusted, the difference between the cut in (20 PSI) and the cut out (40 PSI) can be increased or decreased. The pressure switches can also be adjusted from 20/40 to 25/45 or up to 40/60. there are 2 springs with a nut on top of them, 1 changes both the cut in and the cut out, but keeps the 20 PSI difference, the other changes the 20 PSI difference.The following is a list of problems that may be caused by a pressure switch

The clicking noise

When you run water in the house, you hear a constant clicking coming from your well tank or your well pump. If you have a full minute or more between clicks, everything is fine, if you only have 30 seconds or less between click, you have a problem. The most common cause of this clicking (short cycling of the pump) is a water logged well tank, the bladder in your well tank may have ruptured, and the well tank has no air in the top of it, or if you have a galvanized well tank, it may need to have air added to the tank.
The reason you need to have air in the top of your well tank is, water can not be compressed, but air can, so the air allow the tank to hold pressurized water.

You may ask, why does the pump need to run for at least a whole minute before it shuts off and runs again, when the pump short cycles it puts strain on the pump motor and will cause it to burn out and fail.
Another cause of the short cycling is the pump is to fast for your well tank, or your well tank is too small for your pump, this happens when a non pro replaces a well pump or tank without knowing the difference, submersible pumps comp in many sizes but also in many speeds, for example a 1/2 HP pump is available with speeds of 2 gallons a minute up to more then 12 gallons per minute. The faster pump needs a larger tank, to prevent short cycling. Another cause is when a pipe or check valve has failed, this would cause the clicking sound when the water is not running at all.
Pressure drops to nothing, then suddenly come back.
This is a problem caused by a clogged or blocked pipe or fitting, connected to the pressure switch, or a clog in the bottom of the pressure switch, this blockage cause's the correct pressure, to not get to the pressure switch, to fix this the clog needs to be removed, THINK FIRST!!! WATER AND ELECTRICITY!!!!! not a good combination, you can not remove the pressure switch without removing the wires first, An OSHA inspector told me that more people are killed by 120 volt line power then any other. Most submersible pumps have 240 volts, jet pumps can have 120 or 240 volts, either way it is very dangerous