The GL-235 provides two different types of connections to the pool/spa actuators. For
older actuators with no wire end connector, a 3 position terminal block is used. Connect
the wires to the proper terminal block according to the color code shown in Figure 4.
If the valve operates opposite to the way it is supposed to, reverse the red and white
wires. Be careful not to short the valve output wiring. The GL-235 is fused and shorting
the output will require replacing the fuse.
For newer Hayward, Compool and Jandy actuators (with wire end connectors), two 3-
pin connectors are supplied. Plug the actuator into one of the two 3 pin connectors
as shown in figures 2 or 3. If the valve operates opposite to the way it is supposed to,
disconnect and plug into the other connector.
High Voltage (HV) output: Booster Pump
The GL-235 can control a high voltage booster pump in addition to the normal low
voltage solar valve. Note the high voltage relay contacts are isolated so that the booster
pump can be run on a separate circuit, as required by many local codes. The GL-235
turns on, the valve output will operate first, and then the HV relay will operate 30 seconds
later.
High Voltage (HV) output: Timeclock Override
The GL-235 can also be used to override the filter pump timer. This is very important
if recirculate freeze protection or nocturnal cooling functions are being used. Also, this
function can be used on systems where the system should operate whenever solar heat
is available, regardless of the timer settings. The HV relay will operate approximately
30 seconds after the LV relay.
Sensor Mounting and Wiring
Most installations use a PC sensor to measure the pool temperature and another PC
sensor to measure the solar temperature. Alternatively, an SC-¼ sensor can be screwed
into the pump strainer basket to measure the pool temperature.
Pool Sensor:
Drill a 3/8” (or 5/16”) hole in the PVC pipe. Remove burrs around the hole.
Check that the O-ring is seated on the PC sensor and then insert sensor into pipe.
Tighten hose clamp over the sensor to make a seal—DO NOT OVERTIGHTEN.
Solar Sensor:
Use a screw or silicon adhesive to attach the sensor near the solar
collector array. The sensor does not have to be attached to the collectors. It is only
important that the sensor be exposed to the same sunlight as the collectors. Addition-
ally, the underside of the sensing element may be covered with silicon to minimize wind
cooling.
Other 10K ohm Hayward sensors may be substituted. Wire should be twisted pair
20AWG. Sensor wiring run outdoors must be rated for outdoor use and ensure that
the wire connections are protected from the weather.
Do NOT run sensor wires in the
same conduit or multiconductor cable as the valve actuator wires or any 120/240V
circuit.
For long runs or runs near other electrical wiring use shielded cable (Belden
8428 for outdoor use). Ground the shields to the GL-35/LV ground screw.
3
10
Troubleshooting
No Power Indicator
• Check main power circuit breakers.
• Check fuse
Fuse Replacement
The GL-235 is protected by a fuse located on the left side of the main circuit board.
Replace the fuse with a 2A, type ATO-2 fuse, readily available in most automotive or
electronics stores.
If “Heating” is always on
Disable recirculate freeze protection if enabled. Check that the switch is in the “AUTO”
position. Next verify that the control circuitry is operating properly by disconnecting
the solar sensor from the terminal block. The “Heating” LED should go off and the
“CHECK SENSOR” LED should begin to blink. If “Heating” remains on, there is an
internal circuit failure and the GL-235 will have to be returned for repair.
If “Heating” never comes on
Verify that the switch is in the “AUTO” position, the desired pool temperature dial is
set higher (hotter) that the actual pool temperature, and the solar sensor is warmer than
the pool water. Also check that the switch on the valve actuator is NOT in the "OFF"
position. Disconnect the pool sensor from the terminal block and verify that the
“CHECK SENSOR” LED turns on. If the “CHECK SENSOR” LED does not turn on, there
is an internal failure and the GL-235 will have to be returned for repair. Reconnect the
pool sensor and verify that the “Check Sensor” LED turns off. Next, disconnect the
“solar” sensor from the terminal block and verify that the “CHECK SENSOR” LED
begins to blink. If the “CHECK SENSOR” LED does not begin to blink, there is an internal
failure and the GL-235 will have to be returned for repair.
“CHECK SENSOR” indicator on
If the “CHECK SENSOR indicator is on and NOT blinking, there may be a possible open
circuit or short circuit with the pool sensor. Using a voltmeter, measure the DC voltage
across the terminals of the pool sensor as indicated in figure 5. If the voltage is close
to zero volts, the sensor has a short to ground. Remove the sensor from the terminal
block and measure the voltage across the pool terminals again. If the voltage is still close
to zero volts, there is an internal short and the unit must be returned for repair. If the
voltage is close to five volts, the pool sensor itself may be at fault.
With the sensor disconnected from the unit, measure the resistance of the sensor using
an ohmmeter. At room temperature (25ºC/77ºF) the sensor should measure approxi-
mately 10K ohms (10,000 ohms ± 1%). For other resistance measurements at different
temperatures, consult the table at back of manual. If the sensor is not returning the
correct value, it is defective and will need to be replaced. If the sensor is returning
approximately the correct value, reconnect it to the terminals marked “POOL SENSOR”.
If the “CHECK SENSOR” indicator remains on, the unit is defective and needs to be
replaced.
“CHECK SENSOR” indicator blinking
If the “CHECK SENSOR indicator is blinking, there may be a possible open circuit or
short circuit with the solar sensor. Using a voltmeter, measure the voltage across the
terminals of the solar sensor. If the voltage is close to zero volts, the sensor has a short
to ground. Remove the sensor from the terminal block and measure the voltage across
the solar terminals again. If the voltage is still close to zero volts, there is an internal
short and the unit must be returned for repair. If the voltage is close to five volts, the
solar sensor itself may be at fault.
240 VAC
input power
115 VAC
input power
EARTH
GROUND
EARTH
GROUND
{
{
high
voltage
output
high
voltage
output
Figure 1
