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WATER PUMPS, TANKS, TESTS, WELLS, REPAIRS
WATER CONSERVATION MEASURES
WATER CONTAMINANT LEVELS
WATER FILTERS, HOME USE
WATER HAMMER NOISE DIAGNOSE & CURE
WATER ODORS, CAUSE CURE
WATER PUMP REPAIR GUIDE
WATER PRESSURE LOSS DIAGNOSIS & REPAIR
WATER PUMP SHORT CYCLING
WATER SOFTENERS & CONDITIONERS
WATER TANK REPAIR PROCEDURES
WATER TANK: USES, TROUBLESHOOTING
WATER TESTS, CONTAMINANTS, TREATMENT
WATER TREATMENT EQUIPMENT CHOICES
WELLS CISTERNS & SPRINGS
WELL CHLORINATION & DISINFECTION
WELL FLOW RATE
WELL WATER PRESSURE DIAGNOSIS
WELL YIELD IMPROVEMENT
WINTERIZE A BUILDING
Water pressure gauges:
This article describes the location, use, and operation water tank pressure gauges, how to read, use, repair or replace water pressure gauges.
We discuss water pressure gauge location, accuracy, and uses on water well pump and tank systems. A well pump gauge can help diagnose a variety of well and pump problems including leaks, bad check valves, bad well pumps and more.
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In this photo the water tank pressure gauge is visible mounted on a special brass fitting which is in turn connected to the bottom of the water pressure tank.
The water tank pressure gauge is showing about 37 PSI.
[Click to enlarge any image]
Note that water tank pressure gauges give a general idea of the water pressure measured at the water tank, and that the pressure shown on the gauge will normally drop down to the "pump cut-in pressure" at which point the water pump should start operating, and the gauge pressure will then rise up to the pump "cut out pressure" when the water pump stops.
Water Pressure Indicator Gauge Accuracy
Typical residential water system pressure gauges found at the water tank or water pump are only approximate and are not lab instrument grade, but the water pressure gauge is a very helpful diagnostic when you're diagnosing a loss of water pressure or pump operating problem as well as when you're adding air to a water tank.
How to Repair or Replace the Water Pressure Indicator Gauge on a Water Tank or Pump
If you are installing a new pressure gauge where none has been previously installed, or for more water pressure gauge mounting location options see WATER PRESSURE GAUGE INSTALLATION.
How to Replace a Broken Water Pressure Gauge, or How to Correct A Water Pressure Gauge that Reads too High or Too Low
If the water pressure gauge glass is broken or missing, if the gauge is visibly rusty or damaged, or if the gauge simply stops changing what it indicates despite the water system pressure changing (in other words the pressure shown on the gauge never changes) you should replace the gauge itself.
The well pump is turned off, pressure is drained from the system (you do not have to let all of the water out of the tank, just be prepared for a little spillage). Then the new water pressure gauge is prepared for installation (make sure the gauge bottom threads match those of the old unit being replaced as diameters vary from 1/4" to 1/2").
Water Pressure Gauge Troubleshooting
Reader Question: 8/9/14 Andrew said:
Hi I recently replaced our submersible water pump (DAB Pulsar 40/50 M), because of a faulty electrical component in the pump. I looked around to see if I could get it repaired but the cost was excessive compared the a new one. (It was over 10 years old). There is a float switch attached to the pump which works in conjunction with a pressure switch and gauge mounted on top of the pressurized cold water cylinder.
The system is set to a max pressure of 3 bar. When the pressure drops to about 1.5 bar the pump automatically recharges the water cylinder. After I replaced the pump everything was working fine again, until recently.
The problem now is that when the pump is switched on the system recharges but the gauge is not registering any pressure and the switch doesn't turn the pump off. If I let it run I'm sure it would explode.
I've read through your extensive notes and explanations but can't find anything which specifically relates the our problem.
If your water supply contains silt, iron, debris or the like, I suspect that the gauge pressure port is clogged and possibly there is similar clogging of the pressure sensing port of the pressure control switch. Try replacing the gauge, and cleaning or replacing any clogged small-diameter piping - same for the pressure switch. Keep us posted.
Reader question: relation of water pressure gauge to well pump short cycling
30 Dec 2015 Bev wrote:
Will a broken pressure gauge on a water pump for a two line well system cause short cycles when pumping water into the tank on the interior of the house.
No Bev. Pressure gauges are passive devices - they do nothing but reflect system pressure.
Water pump short cycling causes are given at SHORT CYCLING CAUSES
But it is worth noting that some of the causes of improper or erratic water pump operation, such as debris clogging of a pressure switch sensor port can also cause erratic pressure gauge operation by clogging its own pressure sensor opening as well.
Continue reading at WATER PRESSURE GAUGE ACCURACY
To buy or make your own portable water pressure measurement gauge, see WATER PRESSURE MEASUREMENT.
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Frequently Asked Questions (FAQs)
Question: pressure gauge stuck at zero even if water pressure is 90 psi
(Nov 24, 2012) Ken said:
Hi i would like to ask how come my pressure gauge is stuck at 0 and the pressure switch is not turning off, the water is filling up my tank and i removed the guage water is coming out of it.. I tested my pump with a bucket, it goes up to 90 psi but when i put it in my tank it pumps water, but the pressure gauge won't move even a bit. I remove it there is very strong air coming out of it.. i tried blowing into the pipe connecting the gauge and the tank, but its clean.. i've already closed all the valve drained my tank, and refilled it. i tried testing my tank and it does pump water, i tried changing the pressure gauge and tried it at the shop its also working. Can u guys help me out?
Check for debris clogging at the pressure switch bottom sensor port as well as at the gauge. Replace the gauge.
Question: what is the function of the float in a water pressure tank
5/26/14 robert said:
What does the float do in a water pressure tank
The "float" in a water pressure tank is probably referring to the small float that actuates an air volume control on a water tank that does not use an internal bladder.
For details see
where we discuss the US Gauge & Similar Type 310WJ, Type 300SL, or Type 6 Rectangular Air Volume Controls = Excess Air Vents
Separately at GRAVITY OPERATED WATER TANKS & Open Water Tanks Indoors we describe open water tanks that also use an internal float. The tanks in this group include rooftop water storage tanks and indoor gravity-operated water tanks - these are not pressurized vessels.
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