How to Find & Adjust the Water Pump Pressure Control Switch
InspectAPedia^®  -    

• How to Find & Adjust the Water Pump Pressure Control Switch, what the pump pressure switch looks like, where is it located on the water system?
• What are the controls, switches, valves found on water tanks and water pumps, what do they do, how are they repaired?
• Well pump & water tank diagnosis & repair procedures

This is a typical Water Pump Pressure Control Switch, normally found mounted on piping at the water pressure tank such as in this example where you see a small gray-covered box with electrical wires coming in (power) and out (to pump) of it. The pump pressure control switch, by being connected to the actual water piping in the building, senses the water pressure and when necessary, turns the water pump on.

The water pump pressure control switch either turns on the water pump directly, or (particularly when a submersible water pump is in use), this switch may operate a physically separate (usually wall-mounted) heavier-duty pump relay which turns on the water pump itself.

A Guide to Building Water Pressure by Adjusting or Repairing the Water Pump Pressure Control Switch

• How to Adjust Water Pump Pressure: The detailed, step by step procedure for inspecting and adjusting the water pressure control switch is discussed in detail at ADJUST PUMP PRESSURE CONTROL.
• Diagnosing Water Pump Short Cycling on and off: If your water pump is clicking on and off too often or quite rapidly see SHORT CYCLING.
• Diagnosing & Repairing Lost Air in the Water Tank: The problem of lost air in the water pressure tank along with how to correct that condition are discussed beginning at SIGNS OF AIR LOSS.
• Diagnosing & Repairing a Water Pressure Control or Water Pump Control Switch: We discuss diagnosing and repairing a water pressure control switch that sticks "on" or "off" or simply won't operate, at water pump Pressure Switch Repairs.

If the water pump "short cycle" is very short, clicking on and off, there could be a shortage of air in the water tank, or there could be a problem with the pump control pressure switch itself, or even a dirty and clogged water filter if one is installed on the system. Dirty water filters and other causes of rapid water pump on-off cycling are discussed at CAUSES OF SHORT CYCLING.

These water pump short cycling problems happen with both in-building jet pumps and with in-well submersible pumps. It's trickier to notice a short cycling submersible pump since you won't hear the pump motor, but you will hear the pump relay clicking on and off, or you can see the water pressure gauge cycling up and down rapidly.

This photo shows a green-painted pressure control switch, mounted on the left side of the one line jet pump. You can see a copper tube that runs from the bottom of the pump pressure control switch bottom over to a fitting at the top center of the face of the jet pump.

This tube is sensing system water pressure inside of the pump housing. The bottom of the pump (or water) pressure switch contains a rubber diaphragm that is pushed on by water pressure conducted to it through this tube. The diaphragm in turn operates the pump relay that turns the water pump on and off.

If the water supply is high in sediment often sediment will clog the pressure sensing opening at the bottom of the pressure control. We've tried cleaning out this orifice but it's never proven to be a lasting repair. If your pump pressure switch stops responding to changes in water pressure it probably needs to be replaced.

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