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The solar hot water return plumbing connection is located at the mid left hand side of the solar storage
cylinder and is marked “Connection for Solar Return Pipe”. The bleed valve solar hot pipe is connected to
this inlet which allows hot water from the collector(s) to enter the solar storage cylinder.
It is important not to cross connect solar cold and solar hot pipes to incorrect connections.
The solar cold pipe (pipe work from the circulating pump) connects to the bottom of the solar collector
and may connect to either the left or right hand side of the solar collector.
The solar hot pipe (return pipe work) must connect to the top of the solar collector diagonally opposite to
the solar cold pipe connection.
The hot sensor connection is at the solar hot outlet where the solar hot pipe connects to the solar collector.
Solar Pipe Lengths
The solar hot and solar cold pipes between the solar storage cylinder and the solar collectors shall;
be of bendable grade or hard drawn copper tube. Annealed or soft copper must not be used.
have a continuous fall from the solar collectors to the solar storage cylinder. Horizontal runs of pipe
work are acceptable and may be installed.
not exceed the maximum recommended combined lengths as specified in the following table:
Maximum recommended total combined pipe length (solar cold + solar hot) and number of 90° bends
Pipe Size
1 or 2 Collectors
3 Collectors
Pipe Length
90° Bends
Pipe Length
90° Bends
DN15
40 metres
20
30 metres
20
DN20
NR
NR
40 metres
20
For each additional 90° bend, reduce the maximum total pipe length by 0.5 metres.
For each additional metre of pipe length, reduce the number of 90° bends by two.
Note:
One 90° elbow is equal to two 90° bends.
NR
– not recommended.
It is essential for these requirements to be followed for the solar water heater to operate correctly and
efficiently. Solar pipe work which is oversized, or is too long, or does not have a continuous fall can result in
a reduction in performance or the solar water heater not operating effectively.
Maximum Height to Collectors
The maximum height of a solar
installation from the solar control
unit (circulator) to the top of the
solar collectors, is determined by
the maximum recommended total
pipe length for the system and the
water supply pressure.
The maximum recommended total
pipe length of the solar circuit
should not be exceeded and a
minimum water supply pressure of
200 kPa should be available at the
inlet to the solar water heater,
otherwise
system
performance
may be reduced or the solar circuit
may not be purged of air during
commissioning of the solar water
heater.
Refer to the installation instructions
supplied with the collector kit for
details on the installation of the
solar collectors.
Solar Pipe Work & Insulation
Refer to “Warning: Important Notes for Plumber” on page 25.
