Installation Guide

54
54
Code Fault Diagnosis Step
Remedy
HS
Water Temperature
Sensing Error
1. Check remote thermostat setting
Verify set point setting of remote thermostat is at or below 104°F. If set point of
remote thermostat is OK, or if heater is not congured for remote thermostat, proceed
to step 2.
2. Verify that the water ow is
adequate
Verify that water ow to heater is above minimum required (20 GPM for H150FD and
H200FD, 25 GPM for H250FD and H300FD, 30 GPM for H350FD and H400FD).
Note that intermittent periods of low water ow will cause this error. If OK, proceed
to step 3.
3. Check inlet water temperature
sensor
Compare the heater's temperature reading to the pool water temperature with an
accurate thermometer. If signicantly different, replace inlet water temperature
sensor.
HF
Flame Present
with Gas Valve not
Energized
1. ICB is defective
Using the sight glass, check to see if the ame is present in the unit. If not, replace
ICB. If ame is present, move to next step.
Without disconnecting the valve from the wiring harness, use a voltmeter to determine
if 24 VAC is present at the gas valve connections. If so, replace ICB. If not, move to
step 3.
2. Gas Valve is defective
Replace Gas Valve
LO
Water pressure
switch fault
1. Verify that the pump is running.
This is a normal display when the pump is off. Turn pump on. LO code should clear.
If LO does not clear, proceed to step 2.
2. Verify that water ow is adequate
Verify that water ow rate to heater is above minimum required (20 GPM for
H150FD and H200FD, 25 GPM for H250FD and H300FD, 30 GPM for H350FD and
H400FD). If OK, proceed to step 3
3. Check for faulty wiring or
connection.
Inspect water pressure switch wiring. Ensure wire harness terminals are securely
fastened to spade terminals on water pressure switch. If OK, procced to step 4.
4.Verify state of water pressure
switch contacts.
Remove wire leads from water pressure switch and jumper leads. Operate heater.
Measure continunity across water pressure switch. If open, proceed to step 5. If
closed, LO code is not caused by water pressure switch fault. Remove jumper from
wire leads and reconnect wire leads to water pressure switch.
5. Ensure that low pump pressure
does not exist.
Clean lter or clear blockages. Check position of valves in plumbing system. If OK
proceed to step 6.
6. Check for correct water pressure
switch setting.
Adjust water pressure switch setting as shown on page 33 of Installation Manual (only
if heater is above or below water level). If LO does not clear, proceed to step 7.
7. Water pressure switch is
defective
Replace water pressure switch.
Vent pressure switch
fault (applies only if
indoor installation)
1. Check for faulty wiring or
connection.
Inspect vent pressure switch wiring. Ensure wire harness terminals are securely
fastened to spade terminals on vent pressure switch. If OK, proceed to step 2.
2. Verify state of vent pressure
contacts.
Remove wire leads from vent pressure switch and jumper leads. Operate heater. Measure
continuity across vent pressure switch. If closed, LO code is not caused by vent pressure
switch fault. If open, proceed to step 3. Remove jumper from wire leads and reconnect wire
leads to vent pressure switch.
3. Check for restricted or blocked
ue.
Ensure that ue is not blocked or restricted. See indoor vent sizing requirements in
installation manual. If OK, proceed to step 4.
4. Vent pressure switch is defective.
Replace vent pressure switch.
LO
Temperature limit
switch fault
1. Check for faulty wiring or
connection.
Inspect temperature limit switch wiring. Ensure wire harness teminals are securely
fastened to spade terminals on temperature limit switches. If OK, proceed to step 2.
Figure 32: TROUBLESHOOTING