ABOUT YOUR WATER HEATER
9
BLEEDING THE SOLAR COLLECTORS
It is necessary to purge air from the collector circuit:
• When the water heater is to be turned on and the solar collectors and solar
hot and solar cold pipe work have been drained.
• After maintenance has been conducted on the pipe work and air has
entered the system.
• If the circulator appears not to be circulating water around the system.
Warning: Bleeding the solar collectors should be conducted in the morning,
within three hours of sunrise, when the water temperature inside the solar
collectors is lower.
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 (if it is
not already open) fitted
adjacent to the solar hot
water (from collector) inlet of
the solar storage tank (see
diagram).
• The mains pressure will force
water to flow from the tank
and through the pipe work,
expelling 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: Exercise care to
avoid any splashing of water,
as water discharged from the
solar collectors may be of a
very high temperature.
• Close the bleed valve when water runs freely from the drain line.