Radiantec Solar Water Heater Owner's Manual - Performance
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that should be corrected but it is not an emergency.
Freezing Conditions –
The glycol portion of the Radiantec Basic Solar Domestic Water Heater will not be
harmed by freezing conditions; however the solar storage tank will need to be protected if the building is
unoccupied.
PERFORMANCE
The variability of solar energy and also the variability in the usage patterns of the occupants mean that most
solar energy systems will be supplemental. Solar domestic water heaters are usually designed to provide 60-
90% of the need of a typical family of four. It is generally not practical to design a solar energy system that
will meet 100% of the needs under every circumstance because the over design needed would raise cost-
effectiveness and architecture issues.
ROUTINE MAINTENANCE AND NORMAL OPERATION
The Radiantec Basic Solar Domestic Water Heater is nearly maintenance free. Nevertheless, it should be
checked periodically for normal operation. When the sun comes out, the pump should run and the system
should make abundant hot water. The pump should not run at night. It would be normal for the solar system
to run slowly on a cloudy day and make less hot water or hot water at a lower temperature. It is normal for
the heat dump to activate for short periods of time under very sunny conditions when there is little use of
hot water.
Periodic rainfall should keep the solar panels free of dirt and dust. You may rinse them off with a garden
hose if they get dirty,
but do not do this when the panels are very hot.
The antifreeze solution should be checked every two years for acidification and freeze level protection.
Normal PH is 8.6 and replacement is indicated at 7.0 or below. The PH test can be done using litmus test
strips or an electronic PH meter. The antifreeze solution may last up to 25 years if it is not exposed to air.
This simple inspection will eliminate corrosion and allow a very long service life for the system. To test the
level of freeze protection, use a hydrometer or antifreeze test strip. You may be able to find a test strip that
tests both the PH and the level of freeze protection. A specification sheet for the Anti-freeze can be reviewed
at the end of this manual.
Inspect the external pipe insulation periodically for UV damage and repaint as needed.
The pressure in the glycol loop as indicated by the pressure gauge should be checked periodically. It should
be between 5 and 25 psi. Lower readings might indicate a leak and higher readings could indicate a
stagnation condition.
Condensation within the solar panels
It is not unusual for moisture to condense on the inside of the solar panels. Condensation can be removed
periodically by allowing the system to operate at high temperatures by restricting domestic hot water use
briefly. Expansion and contraction of the solar panels can draw in morning dew. Small air vents are
provided on the back of the solar panels but they are not always fully adequate.