Specifications

61
FLUSHING THE WATER HEATER
It may be necessary to flush the storage tank (52H or 52L tank) and solar collectors (52L) if there is sediment
in the water supply. This should be conducted in the morning, within three hours of sunrise, when the water
or closed circuit fluid temperature inside the solar collectors is lower.
Cover the solar collectors to prevent solar radiation gain and the transfer of heat to the solar storage
tank.
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 flushing or draining
the solar storage tank and / or solar collectors.
This will assist in the transfer of any heat from high temperature water or 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 water, as water discharged from the solar storage tank and
solar collectors may be of a very high temperature.
Note: The water discharged from the water heater may contain sediments and should be diverted away from
any rainwater tank connected to the roof.
To flush the storage tank (52H or 52L tank) and solar collectors (52L):
Turn off the water heater (refer to “To Turn Off The Water Heater” on page 56).
52H / RLX series – 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.
Operate the relief valve lever – do not let the lever snap back or you will damage the valve seat.
Operating the lever will release the pressure in the water heater.
52L / RL series – From the bottom right and top left ends of the solar collectors, unscrew and remove
the end plugs.
52H / RLX series – Undo the union at the cold water inlet to the solar storage tank and attach a hose.
Flush and hose inside tank:
 disconnect and remove the booster heating unit,
 Place a hose inside the tank,
 Open the isolation valve to the hose,
 Allow hose to run until water runs clear from the solar collectors (52L) or from the hose connected
to the cold water connection (52H),
 Close the isolation valve to the hose and remove the hose from the tank,
 Replace and reconnect the booster heating unit,
52H / RLX series – Disconnect the hose from the cold water inlet and reconnect the cold water pipe
work.
52L / RL series – Open the cold water isolation valve to the water heater.
 Allow water to flow from the solar collectors until it is clear of any sediment.
 When satisfied the solar storage tank and solar collectors are flushed, close the cold water isolation
valve to the water heater and reconnect all fittings to their original location.
Open the cold water isolation valve to the water heater fully, check fittings for leaks and switch on the
power.
It is recommended to flush the solar storage tank and solar collectors every five years. This will assist in
keeping the solar collectors, solar cold pipe and solar hot pipe clear of sediment.