48
BLEEDING THE SOLAR COLLECTORS
Upon completion of the installation, it is necessary to purge the air
from the collector circuit.
To purge air from the collector circuit:
Ensure the water heater is full of water and all of the hot taps are
turned off.
Using a flat blade screwdriver, open the bleed valve fitted
adjacent to the solar hot water inlet of the solar storage tank (see
diagram).
The mains pressure will force water to flow from the tank and
through the pipe work, forcing air from the collector circuit
through the bleed valve. This is evidenced by spurting of water
from the drain line connected to the bleed valve.
Warning:
Stand well aside of the air bleed valve drain pipe
discharge point and exercise care to avoid any splashing of
water, as water or in some circumstances steam discharged from
the solar collectors may be of a very high temperature.
Close the bleed valve when water runs freely from the drain line.
SOLAR CONTROLLER OPERATION AT START-UP
When the electrical supply is switched on to the solar control unit at start up:
If there is no solar gain, the circulator will not activate and the green LED will emit a slow pulse.
The slow pulse indicates the circulator is not activated and the power to the solar control unit has been
on for less than 48 hours.
If there is solar gain, the circulator activates and the green LED will emit a series of three (3) flashes.
The three (3) flashes indicate the circulator is operating and power to the solar control unit has been on
for less than 48 hours.
The circulator will operate at full speed for approximately fifteen (15) seconds.
After fifteen (15) seconds, the solar controller will commence to pulse the circulator to reduce the
flow rate through the collector circuit. This will increase the temperature rise across the solar
collectors and assist in maximising the system efficiency for the available solar energy. It is normal
operation for the circulator to experience a pulsing effect.
The red LED may emit a rapid pulse for a short period (whilst the green LED is emitting a series of
three (3) flashes), particularly if the solar collectors were left uncovered during the final stages of the
installation and commissioning procedure.
This indicates a temperature difference between the hot sensor and cold sensor of greater than 45°C
and does not represent a fault code. This is the result of a build-up of heat and increase in water
temperature in the solar collectors prior to the switching on of the electrical supply to the solar control
unit.
The rapid pulsing of the red LED will cease as the water circulates and the heat is dissipated from the
solar collectors. This should be within four (4) to five (5) minutes of start up, but may take up to ten (10)
minutes
Whilst the red LED is emitting a rapid pulse, the circulator will operate at full speed. After the red LED
has extinguished, the solar controller will commence to pulse the circulator to reduce the flow rate
through the collector circuit.
AIR BLEED VALVE & SOLAR
NON RETURN VALVE ASSEMBLY
Solar Pumped Open Circuit
