Rheem Solar Thermosiphon Water Heater Owner's Manual And Installation Instructions page 47

INSTALLATION CHECK LIST
Once the installation is completed and before the tank is full of water and the collector circuit is full of heating
fluid, it is IMPORTANT to check the following:
The solar hot and solar cold pipes grade downwards with a continuous fall of not less than 10° from the
solar storage tank to the solar collectors. If in doubt use a spirit level.
On a pitched roof installation without a frame, the hot outlet side of the collector array is between
12 – 15 mm (for one solar collector), or

24 – 30 mm (for two solar collectors), or

36 – 45 mm (for three solar collectors)

higher up the roof from the horizontal than the solar cold side of the collector array. If in doubt use a
spirit level.
On a frame installation, depending upon the positioning of the frame on the roof and any fall the roof
may have, ensure the collector rail is either horizontal or is higher on the hot outlet side of the solar
collectors. If in doubt use a spirit level.
47
SYSTEM ASSEMBLY