Water pressure control adjustment nuts (C) D FriedmanWater Pump Pressure Control Switch Safety Warning
Manufacturer's warnings when adjusting the pump pressure switch

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Water pump control switch safety:

This article describes how to adjust building water pressure by setting the water pump cut-in and cut-out pressure on the well water pump pressure control switch.

We also point to our article on how to adjust building municipal or community water pressure at a building.

Green links show where you are. © Copyright 2017, All Rights Reserved.

Pump Pressure Control Switch Safety Warnings & Procedures

Photograph of a water pressure tank control valve

Water Tank rupture safety hazards: can damage equipment or injure someone nearby. Every tank which is pressurized (such as by water or air) should have a pressure relief valve installed - a safety device required by building codes in many jurisdictions.

If a pressure relief valve is not installed on your water tank ask your plumber to provide one promptly.

Watch out: Fatal Electrical Shock Hazard if you remove the cover of the pump pressure control switch (discussed above at ADJUST PUMP PRESSURE CONTROL) you can get access to the two nuts that adjust the operating pressures of the water pump.

But be careful! There are also live electrical contacts exposed in this area. If you touch them, especially being near water piping, there is a serious risk of death by electrocution. Watch what you touch, or have a professional plumber or electrician do this job for you.

While you're on the topic of water pumps, tanks, and controls, here are some safety tips about water pressure tank relief valves and electrical safety around this equipment. Be sure to see our full article on water pump and water tank safety, located at WATER PUMP SAFETY .

Pump Pressure Control Switch Safety Warnings from the Manufacturer

Square D also has these safety warnings printed on a label attached to new switches. We have expanded the text a bit for clarity:

Watch out: But we add that this kind of pressure could certainly explode some water tanks so be sure not to set the pump to a pressure that is higher than what your water tank or piping are intended to withstand.We know of a fatality that happened from just that problem. Absent any other guidance I would not set the water pressure in a building over 70 psi.

And we would be sure that a PRESSURE RELIEF VALVE [web article] has been installed on the water tank.

Watch out: more subtle than the dangers than the overpressure dangers we describe above, if you increase the pump-out rate on a water well that has a marginal flow rate (the rate that water flows into the well), you may pump the well dry, losing pump prime, losing all water pressure, or in the case of running the pump "dry", damaging the pump.

For these reasons it's best to not over-do the cut-out pressure. From a cut out of 40 to even an experimental cut out of 50 psi is ok if you monitor for signs of trouble. But setting the cut-out from 40 psi all the way up to 70 psi is asking for trouble.

More Water Pump Pressure Switch Safety Warnings

The following safety warnings emerged from responding to reader questions about adjusting the water pump pressure control switch:

Watch out: don't run the water pressure control with too narrow a differential between the cut-in and cut-out or the pump may just sit there short-cycling until you burn up the motor. If your pump is staying on for less than 30 seconds (I prefer longer), you may be heading for trouble.

Watch out: setting the cut-out water pressure too high can cause the pump to never turn off or at high pressures you may find leaks at fixtures. And high water pressure that exceeds the rated water tank pressure can burst the tank - a very dangerous event. Also make sure your pressure tank has a relief valve installed.

Watch out: do not try setting up the pressure on the pump pressure control switch in this case. Since your pump is tripping the circuit breaker there is a problem to find and fix first: such as a failing pump motor, wiring error, or other unsafe condition.

The pressure control switch sets the water pressure at which your pump turns on and off. Typically these switches are set to turn on at 20 and off at 40 psi or on at 30 and off at 50 psi.

If your neighbor set the pump cut-out pressure too high, your water pump may simply be unable to ever reach the "Cut off" pressure - so the pump will run until it overheats and shuts off by an internal thermal overload switch. Usually these switches reset automatically when the pump cools down.

But running the pump this way is

- DANGEROUS - too much pressure could burst a water pressure tank or other plumbing parts, even injuring someone

- and it can ruin your well pump by burning out the motor

You need help from someone with a bit more expertise, perhaps a real plumber who knows how to adjust the pump pressure control correctly.

Watch out: messing with a pump pressure control switch exposes live electrical connections - you can be killed if you touch live wires. Another catastrophe to avoid is setting the pressure too high, causing leaks or worse, a burst water tank that could injure anyone nearby.

Watch out: If the clicking pressure switch is switching the pump on and off very rapidly, say every second, TURN THE PUMP CIRCUIT OFF immediately to avoid damaging the equipment. Then check for a clogged water filter, a water valve that should be open is closed, or a waterlogged preside tank

Watch out: I wouldn't keep pressing on the relay. There's live 120V or 240V in that switch - touching exposed wires or connectors is asking for a potentially fatal shock. Keep me posted, what we learn will help other readers.


Continue reading at WATER TANK PRESSURE RELIEF VALVE - what are water tank pressure relief valves, where are they installed, why are they needed? or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.


Suggested citation for this web page

WATER PRESSURE SWITCH SAFETY at - online encyclopedia of building & environmental inspection, testing, diagnosis, repair, & problem prevention advice.


Or use the SEARCH BOX found below to Ask a Question or Search InspectApedia


Frequently Asked Questions (FAQs)

Click to Show or Hide FAQs

Ask a Question or Search InspectApedia

Questions & answers or comments about Setting the Water Pump Pressure Switch and Improving Water Pressure.

Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.

Search the InspectApedia website

Comment Box is loading comments...

Technical Reviewers & References

Click to Show or Hide Citations & References

Publisher's Google+ Page by Daniel Friedman