LX and LT Low NOx Pool/Spa Heater
Page 35
LX/LT H
EATER
S
ERVICE
D
IAGNOSTIC
G
UIDE
D
ISPLAY
C
ODE
C
AUSE
R
EMEDY
LOW PRESS *
(pressure switch)
1. Pump is not running.
1. This is a normal display when the pump is
OFF
.
No Service
Required.
2. Low pump pressure.
2. Clean filter or clear blockage/check position of valves in
plumbing system.
3. Device connected at
“Fireman Switch” terminal
block is open.
3. This is a normal display when a device connected to the
“Fireman Switch” operates to open the safety circuit on the
heater.
4. Pressure switch fault.
4. Adjust or replace pressure switch.
Refer to qualified service personnel.
5. Failed fuse
5. Check heater wiring for shorts, replace fuse.
HI LIM SW
(hi-limit switch)
1. Water temperature in
heater exceeds the internal
limit.
1. Perform Temperature rise test. Identify and correct cause of
overheating.
Refer to qualified service personnel.
2. Limit switch fault.
2. Identify and correct loose connections or replace
switches.
Refer to qualified service personnel.
EXT SW 1
(extra switch 1)
1. Exhaust temp. limit switch
tripped. (manual reset)
1. Verify proper fan operation. Check for restriction or blockage
of flue. Reset switch after problem is corrected.
2. Exhaust temp. limit switch
fault.
2. Identify and correct loose connections or replace switch.
Refer to qualified service personnel.
3. Fusible link fault
3. Identify and correct loose connections or replace fusible link.
Refer to qualified service personnel.
AIR FLO SW
(air flow switch)
1. Broken, split, pinched or
disconnected fan/switch
tubing.
1. Check tubing and replace if necessary.
2. Fan not operating.
2. Correct fault or replace fan.
Refer to qualified service personnel.
3. Fan running slow or
premature fan failure.
3. Verify proper wiring for 115VAC or 230VAC.
Refer to
qualified service personnel.
4. Air flow restricted at
intake or discharge.
4. Check for proper clearances around heater and for adequate
room ventilation if enclosed. Inspect for blockage or restriction
at discharge or flue.
Refer to qualified service personnel.
AGS
(automatic gas
shut-down)
1. Oscillating
pump
pressure.
1. Clean filter or identify and repair cause of pump
oscillation.
2. Low gas supply pressure.
2. Identify and repair incorrect supply pipe size or pipe line
blockage.
Refer to qualified service personnel
.
3. No flame at burners.
3. Identify and correct loose wiring connections, or
problems with igniter, flame sensor , gas valve, or ignition
control.
Refer to qualified service personnel.
EXT SW 2
(extra switch 2)
Not used in this model.
TEMP
SENSOR*
(temperature
sensor)
1. Faulty wiring or
connection
2 Failed Sensor
1. Inspect Sensor wiring. Ensure sensor is plugged into back of
control panel.
2. Replace Temperature Sensor.
Refer to qualified service personnel
*
NOTE:
When these messages are displayed, the Controls are still operable and the heater will operate normally when the displayed
condition is remedied. Faults shown above without an asterisk (*) will shut down the Heater and Control Panel and a flashing
“SERVICE” is displayed.
Table 11.
