Rheem RS120-64BP Use & Care Manual page 24

Open the upper charge faucet and allow the pressure
from the expansion tank to push the water in the
The temperatures generated by your SolaRay sys-
glycol loop back to prime the pressure pump. When
the hose in the bucket containing the glycol mixture
tem will vary throughout the year.
stops bubbling you may begin charging the collector
loop with glycol.
Northern Hemisphere the water temperature will
With both charge faucets now open, run the Flojet
be hottest in the spring and summer months
pressure pump until the pinkish glycol mixture begins
flowing into the empty bucket. Quickly switch the
while cooler temperatures are to be expect from
hose from the empty/return bucket to the bucket
containing the glycol mixture. Continue to circulate
November through March. On sunny days sys-
the fluid using the pressure pump until the bubbling
has stopped and the air has been purged.
tem temperatures may range between 110ºF to
4.11.5 After charging the collector loop, shut the
180ºF depending upon the season and hot water
lower charge faucet and let the pressure pump
drive up the loop pressure to the appropriate level
(Generally in the range of 25 PSI). To more accurately
demand.
calculate the proper pressure measure the height of the
solar collector above the solar storage tank and divide
blends the hot and cold water supplies to deliver
this number by 2.31. Then add 20 PSI to this number.
As a word of caution, the pressure in the glycol
hot water to your fixtures at a safe, controlled
loop should not exceed 45 PSI when the system is
24
temperature.
TANK SENSOR
The mixing valve described above
operational on a good sunny day. Contact your solar
contractor if the charged collector loop pressure
exceeds this threshold.
Your Rheem solar water heating system must be
charged and the fluid quality maintained by an
experienced contractor. If the system is drained during
the winter, or you notice a significant drop in collector
loop pressure, contact your installation contractor
immediately for service. The glycol HTF provides
the freeze protection for your system and must be
properly maintained. An experienced contractor
should periodically check the HTF fluid quality.
4.11.6 Dowfrost HD HTF
To ensure maximum effectiveness for corrosion
protection, the glycol inhibitor package is designed
for a minimum 25-30 percent concentration of
glycol in water. Table 4 shows the concentrations of
Dowfrost HD required to provide freeze and burst
protection at various temperatures. Use the mixture
most appropriate for your climate. Do not use a
higher glycol to water concentration than necessary,
fig.18
In the