Sears 390.250251 User manual

For the repair or replacement parts you need
Call 7 am - 7 pm, 7 days a week
1-800-366-PART
(1-800-366-7278)
For in-home major brand repair service
Call 24 hours a day, 7 days a week
1-800-4-REPAIR
(1-800-473-7247)
For the location of a
Sears Repair Service Center in your area
Call 24 hours a day, 7 days a week
1-800-488-1222
For information on purchasing a Sears
Maintenance Agreement or to inquire
about an existing Agreement
call 9 am - 5 pm, Monday-Saturday
1-800-827-6655
MAINTENANCE
AGREEMENT
America's Repair Specialists
REPAIR SERVICES
America's Repair Specialists
REPAIR SERVICES
America's Repair Specialists
REPAIR SERVICES
Sears, Roebuck and Co., Hoffman Estates, IL 60179 U.S.A.
OWNER’S
MANUAL
Model No.
390.250251
The model number of
your Shallow Well Jet
Pump will be found on
the pump body.
When requesting service
or ordering parts, always
give the following
information:
• Product Type
• Model Number
• Part Number
• Part Description
SHALLOW WELL
JET PUMP

REPAIR PARTS
11
Key Part
No. Number Description
34 2761 Air Volume Control
35 U78-774P Reducer Bushing - 1-1/4” x 1/4” NPT
36* U37-17GPT Nipple - 1/4” x 1-1/2”
37 U37-205P Tube - AVC
38 U111-86T Compression Fitting Elbow - 1/4” NPT
39 U111-100T Compression Fitting Straight - 1/8” NPT
* Standard hardware item. May be purchased locally.
Sears Shallow Well Jet Pump
1/2 HP Model 390.250251
Air Volume Control Package
(Not Furnished - Must be purchased separately)
Key Part
No. Number Description
1A U18-1103 Overload
1B U18-1180 Terminal Board
1C U18-1098 Contactor
1D U18-128 Governor
1E U18-526 Capacitor
Motor Service Parts
1A
L1
L2
1B 1C
1D
1E
Wiring omitted
for clarity

REPAIR PARTS
10
1
2
345
6
7
8
16
9
11
12
13
14
AVC Port
15
10
17
18
19 20 21
1609 0195
Model 390.250251
Key 1/2 HP Qty.
No. Part Number Used Description
1# J218-953C 1 Motor - 115/230V - 60 Cycle
2 C69-2 1 Water Slinger
3 N3-9 1 Seal Plate
4 N20-35 1 Gasket - Seal Plate
5 2784 1 Shaft Seal
6 J105-40P 1 Impeller
7 L1-25P 1 Diffuser
8 N20-34 1 Gasket - Diffuser
9 N32P-67 1 Venturi
10 N34P-17 1 Nozzle No. 43
11 U111-211T 1 Hose Barb
12 U78-60CT 1 Pipe Plug - 3/4” NPT - Square Head
13† N176-21T 1 Pump Body Assembly
14 N212-12P 1 Check Valve
15 U78-56CT 1 Pipe Plug - 1/8” NPT - Square Head
16 U78-57CT 1 Pipe Plug - 1/4” NPT - Square Head
17* U30-75ZP 4 Capscrew - 3/8”-16x1-1/4” Hex Head
18 U37-672P 1 Switch Tube
19 2764 1 Pressure Switch
20 U36-112ZP 1 Locknut - 1/2”
21 L43-5C 1 Connector
• F642-2392 1 Owner’s Manual
To Order Parts,
Call Sears Product Service,
1-800-366-7278
†Includes Key Nos. 9, 10, 13, and 14.
* Standard hardware item. May be purchased locally.
# For repair or service to motors, always give the motor model number and any other data
found on the motor model plate.
• Not illustrated.
Sears Shallow Well Jet Pump – 1/2 HP Model 390.250251
See Page 11 For Motor Service Parts

TROUBLESHOOTING CHART
9
SYMPTOM POSSIBLE CAUSE(S) CORRECTIVE ACTION
Motor will not run 1. Disconnect switch is off 1. Be sure switch is on
2. Fuse is blown 2. Replace fuse
3. Starting switch is defective 3. Replace starting switch
4. Wires at motor are loose, 4. Refer to instructions on wiring. Check and tighten all wiring.
disconnected, or wired incorrectly
5. Motor is wired incorrectly 5. Refer to instructions on wiring
6. Pressure switch contacts are dirty 6. Clean by sliding pieces of plain paper between contacts
Motor runs hot and 1. Motor is wired incorrectly 1. Refer to instructions on wiring
overload kicks off 2. Voltage is too low 2. Check with power company. Install heavier wiring if wire
size is too small. See wiring instructions
3. Pump cycles too frequently 3. See section below on too frequent cycling
Motor runs but no 1. Pump in new installation did 1. In new installation:
water is delivered not pick up prime through:
a. Improper priming a. Re-prime according to instructions
b. Air leaks b. Check all connections on suction line, air volume control, and jet
c. Leaking foot valve c. Replace foot valve
2. Pump has lost prime through: 2. In installation already in use:
a. Air leaks a. Check all connections on suction line, air volume control,
jet and shaft seal
b. Water level below suction b. Lower suction line into water and re-prime. If receding water level
of pump in well exceeds suction lift, a deep well pump is needed
3. Jet or impeller is plugged 3. Clean jet or impeller according to instructions
4. Check valve or foot valve is stuck 4. Replace check valve or foot valve
in closed position
5. Pipes are frozen 5. Thaw pipes. Bury pipes below frost line. Heat pit or pump house.
6. Foot valve and/or strainer are 6. Raise foot valve and/or strainer above well bottom
buried in sand or mud
Pump does not 1. Water level in well is lower than 1. A deep well jet pump may be needed (over 20 ft. to water)
deliver water to full estimated
capacity (Also 2. Steel piping (if used) is corroded or 2. Replace with plastic pipe where possible, otherwise with
check point 3 limed, causing excess friction new steel pipe
immediately above) 3. Offset piping is too small in size 3. Use larger offset piping
Pump pumps water 1. Pressure switch is out of adjustment 1. Adjust or replace pressure switch
but does not shut or contacts are “frozen”
off 2. Faucets have been left open 2. Close faucets
3. Jet or impeller is clogged 3. Clean jet or impeller
4. Water level in well is lower than 4. Check possibility of using a deep well jet pump
estimated
5. Motor is wired incorrectly 5. Refer to instructions on wiring
Pump cycles too 1. Standard pressure tank is water- 1. Drain tank to air volume control tapping. Check air volume control for
frequently logged and has no air cushion defects. Check for air leaks at any connection
2. Pipe leak 2. Check connections
3. Faucets or valves are open 3. Close faucets or valves
4. Foot valve leaks 4. Replace foot valve
5. Pressure switch is out of adjustment 5. Replace pressure switch
6. Air charge too low in SEARS 6. Disconnect electrical power and open faucets until all pressure is
Captive Air®Tank relieved. Using automobile tire pressure gauge, check air pressure in
tank at the valve stem located at top of tank. If air pressure is lower,
pump air into tank from outside source until proper air pressure is
reached. Check air valve for leaks, using soapy solution, and replace
core if necessary.
Air spurts from 1. Pump is picking up prime 1. As soon as pump picks up prime, all air will be ejected
faucets 2. Leak in suction side of pump 2. Check suction piping
3. Well is gaseous 3. Change installation as described in manual
4. Intermittent over-pumping of well 4. Lower foot valve if possible, otherwise restrict discharge side of pump

MAINTENANCE
4. Lubricate inside diameter and outer face of rubber
drive ring with soapy water and slide assembly on
motor shaft (sealing face first) until rubber drive
ring hits shaft shoulder.
5. Screwimpelleronshaftuntilimpellerhubhitsshaft
shoulder.Thiswill automaticallylocatesealinplace
and move the sealing washer face up against seat
facing.
Cleaning Impeller
1. Disconnect power.
2. Remove motor.
(a) Remove motor wiring from pressure switch.
(b) Remove 4 capscrews, Key No. 17, Page 10,
which hold the motor to the pump body.
(c) Remove motor, seal plate, impeller and diffuser,
(Key Nos. 1, 3, 6 and 7), Page 10, as a unit.
Diffuser, Key No. 7, can now be lifted off and the
impeller exposed and cleaned.
Replacing Venturi
Follow Steps 1 and 2 above, for Cleaning
Impeller.
1. Remove venturi, Key No. 9, Page 10, by turning it
counter-clockwise.Thiswillexposethenozzle,Key
No. 10, which can be removed by using a 5/8” hex
socket and turning it counter-clockwise.
2. To replace venturi, turn it clockwise until snug.
3. Replace all parts. Connect motor wiring and turn
on power.
Cleaning Shallow Well Jet
Follow Steps 1 and 2 above, for Cleaning
Impeller.
1. Observe venturi, Key No. 9, Page 10, which is po-
sitioned in pump body, Key No. 13.
2. Nozzle, Key No. 10, is directly behind the venturi
in the pump body.
3. Insert an ice pick or other small diameter pointed
tool through the venturi and into the nozzle. This
will dislodge foreign material.
4. Foreign material will drop to the bottom of the
pumpbody(directlybelowthenozzle)andmustbe
removed.
5. Replace all parts. Connect motor wiring and turn
on power.
HOW TO HANDLE
A GASEOUS WELL
In some localities well water contains gases which
must be allowed to escape before the water is used.
This can be done as shown in Figure 6.
A good way of delivering gas-free water is to suspend
a pipe, closed at the bottom and open at the top, sur-
rounding the suction pipe, Figure 6. Since the gases
riseinthewellcasing,thewatersuckeddown through
the pipe and into the suction pipe is free of gas. It is
imperative that this type of well be vented to the out-
side of any enclosure.
Air Control In Flowing Wells
Flowing wells, or wells with little or no drawdown,
could create a special problem in air control in the op-
eration of your water system.
In such cases, it is recommended that you install a
SEARSCaptiveAir®Tank, inwhichanaircontrolmech-
anism is not required.
8
Figure 6
Not
to
Scale
Pipe strap or
wire to hold
pipe sleeve
Pipe
sleeve
Pipe
cap
Tail
pipe
Foot
valve
2369 0396
Gases
rise to
surface
Pump Discharge Pumping Depth in Feet
Model Description Suct. Disch. Pressure PSI 5’ 10’ 15’ 20’
1/2 HP Standard S.W. Jet
390.250251 Use 1-1/4” Plastic Pipe 1-1/4” 3/4” 40 7.3 6.2 5.2 4.2
80 PSI Minimum Rating
Pump Performance (In Gallons per Minute)