49
DRAINING THE CLOSED CIRCUIT
It is recommended to drain the solar collectors and heat exchanger every five years. The closed circuit fluid
should be checked and if necessary replaced. Draining the solar collectors and closed circuit should be
conducted within three hours of sunrise, when the closed circuit fluid temperature inside the solar collectors
is lower.
To drain the solar collectors and closed circuit:
Cover the solar collectors to prevent solar radiation gain.
Failure to do so may cause a safety issue.
Open a hot water tap and allow the water to run for five minutes immediately prior to draining the solar
storage tank.
This will assist in the transfer of any heat from high temperature closed circuit fluid in the solar collectors
to the water in the solar storage tank.
Close the hot water tap.
Warning:
Exercise care to avoid splashing of closed circuit fluid, as fluid discharged from the solar
collectors may be of a very high temperature.
Note:
The closed circuit fluid discharged from the solar collectors can render the water in a rain water tank
unusable and should be diverted away from any rainwater tank connected to the roof.
Operate the closed circuit pressure relief valve on the right side of the solar storage tank to relieve the
pressure from the closed circuit.
Warning:
Relieved air or closed circuit fluid may be hot.
Open the service valve at the bottom right corner of the solar collectors and attach a hose.
Place the end of the hose into a container.
Remove the retaining clip and the closed circuit pressure relief valve from the tank vent socket.
Allow the closed circuit fluid to drain into a container and dispose of in accordance with the relevant local
authority.
Warning:
Closed circuit fluid may be hot.
To fill the solar collectors, refer to
“To Fill The Closed Circuit”
on page 46.
