MARK OF THE
ORIGINATOR
CODE
REASON
ACTION
CAUSE & REMEDY
E1
Rapid cycle
Excessive amp draw
Switch continues to operate.
See “Pump Starts Too Often” above.
Have pump checked for proper operation.
E2
Low-suction
(running pressure)
below 10 PSI
Shuts off pump. Auto restart
after 60 min.
1. Determine cause of low-suction.
2. Check Wiring.
3. Inspect pump.
E3
Improper voltage
Shuts off pump.
Restore voltage to proper range. Pump automatically
restarts with proper voltage.
To reset control at any time, press
buttons simultaneously for 5 seconds.
To "invert" the display for easier viewing, press
together for 3 seconds.
The Guardian CP
™
incorporates built-in diagnostics. If the AMTROL Pressuriser
®
is not functioning properly or is inoperable, look for
a error code (example E1) on the digital readout before proceeding. Error codes are listed in the table at the bottom of this page.
PROBLEM
CAUSE
SOLUTION
Pump will not start.
1. No Power.
2. Faulty wiring.
3. Damaged motor.
4. Damaged control.
1. Check circuit breaker and fuses, tighten connections.
2. Check wiring per installation diagram in this booklet. If pump hums,
but will not start, check pump motor wiring (115/230V).
3. If display illuminates with no error code, but pump will not start,
replace pump.
4. If power is present at L1/L2 but display is blank, replace control.
Pump runs but will
not build pressure.
1. Supply closed/blocked.
2. Bypass loop open.
3. Pump plumbed backwards.
4. Bad internal parts.
1. Open all supply valves, ensure check valve is not sticking, clean
any filters.
2. Close bypass valve.
3. Reverse inlet/outlet.
4. Check for bad seals or broken impeller. Repair or replace as
necessary.
Pump builds
pressure but will not
shut off.
1. Operating pressure set too high.
2. Bad internal parts.
3. Control line blocked.
1. Reduce control setting as necessary.
2. Check for bad seals or broken impeller. Repair or replace as
necessary.
3. Remove control line and blow compressed air to clear.
Pump starts too often
(cycles under 30
sec.).
1. Control differential too narrow.
2. Tank precharge incorrect.
3. Waterlogged pressure tank.
1. Set cut-in and cut-out 20 psi apart.
2. Set air pressure 2 psi below cut-in while pump is off and gauge
pressure is zero.
3. If water emerges from tank air stem when depressed, replace tank.
THE GUARDIAN CP CONTROL CONTAINS NO SERVICEABLE PARTS. REMOVAL OF MAIN CIRCUIT BOARD COVER WILL
VOID WARRANTY.
Troubleshooting
© 2019 Worthington Industries Inc.
Part #: 9040B140 (01/19)
One or more features of this product are covered by U.S. patents, visit www.amtrol.com/patents for more information.
1400 Division Road, West Warwick, RI USA 02893
T: 800.426.8765
www.amtrol.com
