Replace a faulty pump pressure switch
1 of 3
Photo 1: Shut off the power, then disassemble
Label each wire with tape. Then unscrew
the conduit locking ring and pull the wires
and conduit out of the switch.
2 of 3
Photo 2: Swap the switch
Unscrew the old switch and nipple.
Replace with new parts.
3 of 3
Photo 3: Replace the pressure gauge
Slap your adjustable wrench around the flats on the gauge and unscrew it. Then screw
in a new one and tighten it down.
Your well pump gets its marching
orders from the switch mounted on the
pressure tank. When the switch acts
up (and they all do eventually), you’ll
see all kinds of strange behavior (pump
won’t turn on, turns on erratically or
won’t shut off). Replacing the pressure
switch is cheap and takes only about
an hour.
Diagnose a cranky switch by rapping
on it with a screwdriver handle.
If the pump runs (you’ll hear it click)
or quits, you’ve nailed the problem.
But even if it doesn’t respond, it’s still
worth replacing the switch. Replace
it with a new one (about $24 at rural
home centers and amazon.com).
Switches come in three pressure
ranges: 20 to 40, 30 to 50 and 40 to
60 psi. Always replace your switch
with one of the same rating (usually
printed inside the plastic cover
of your old switch). Also buy a new
pressure gauge (less than $10) and
a 1/4-in. x 6-in. galvanized nipple.
Flip the breaker to the pump
switch and check it with a voltage
sniffer to make sure it’s off. Then
disconnect the wiring (Photo 1).
Close the valve from the pressure
tank to the house. Then drain the
pressure tank. Next, remove the old
switch (Photo 2) and gauge (Photo 3).
Wrap the pipe threads with Teflon
tape and reassemble. Install the
wiring, close the faucet and repower
the pump.
