N. thermostat adjustment, Part 7 - fluid quality, A. solar loop fluid quality – HTP SSU-119SE User Manual

Page 25: B. fluid safety labeling, C. freeze protection

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25

LP-199 REV. 4.15.14


After the water and electrical connections have been made and the tank has been
filled with water and purged of air, turn on power to the heater. The heater is now
operational.

N. THERMOSTAT ADJUSTMENT

The thermostat is located in the front of the heater. The access cover must be
removed to adjust the factory default setting of 119

o

F. This temperature is satisfactory

for average household use.

If an adjustment is necessary, turn off the power to the heater, remove the black
access cover and insulation. The thermostat protective cover should not be removed.
Set the temperature indicator to the desired temperature, replace insulation and
access cover. Turn on power to the heater.

O

. COMBINATION “THERMOSTAT AND HIGH LIMIT CONTROL (ECO)”

This heater is equipped with a combination thermostat and high limit safety. If for any
reason the water te

mperature becomes excessively high, the “High Limit Control

(ECO)” breaks the circuit to the heating element. Once the switch opens it must be
reset manually. However, THE CAUSE OF THE OVERHEATING CONDITION MUST
BE CORRECTED FIRST. Refer to the Troubleshooting section for possible causes.
To reset, press the red reset button as shown in Figure 12. Replace the insulation and
black access cover before restoring power to the system.

PART 7 - FLUID QUALITY

A. SOLAR LOOP FLUID QUALITY

Fluid in direct flow through the solar collectors must first meet potable water requirements; any fluid circulated through the collectors
should be non-corrosive to copper. In addition, water quality must meet the following requirements listed below.

Hardness: Less than 7 grains
Chloride levels: Less than 100 ppm
pH levels: 6-8
TDS: Less than 2000 ppm
Sodium: Less than 20 mGL

In order to meet health and safety regulations, solar system antifreeze fluid should be food grade polypropylene glycol, FDA rated as
“generally recognized as safe” (GRAS). Using proper concentrations of glycol, solar systems can be operated at ambient temperatures
as low as -60

o

F. Freeze tolerance limits are based upon an assumed set of environmental conditions. Refer to the DOWFROST

specification sheet in the back of this manual for recommended concentrations. If using a glycol/water mix, the water must meet the
above requirements, and the glycol content of the liquid must not exceed 50%, unless the manufacture specifies that a different ratio is
recommended for use with solar water heaters. Glycol may need to be changed periodically (every 3-5 years) to prevent it from
becoming acidic; please refer to the guidelines provided by the glycol manufacturer regarding replacement.

NOTE: The use of glycol not recognized as GRAS is allowed in double wall heat exchanger models ONLY.

B. FLUID SAFETY LABELING

Included with your solar system is a set of labels which describe component function. These labels alert the owner to potential hazards.
Affix these labels by stri

ng/wire/tie on valves, and/or “peel and stick” on pipe insulation. Labels on the solar loop system must contain

the following warning:

“No other fluid shall be used that would change the original classification of the system. Unauthorized alterations to this system could
result in

a hazardous health condition.” All labeling MUST be in place at final inspection.

C. FREEZE PROTECTION

“Freeze tolerance limits are based upon an assumed set of environmental conditions. Extended periods of cold weather, including

ambient air temperatures above the specified limit, may cause freezing in exposed parts of the system. It is the owner’s responsibility to
protect the system in accordance with the Supplier’s instructions if the air temperature is expected to approach the specified freeze
tolerance limit.”

For areas with temperatures not falling below

–5

o

C / 23

o

F, a simple low temperature controller may be used to guard against freezing.

If necessary, backup freeze protection in the form of an uninterrupted power supply (UPS), or freeze valves (which open to allow water
to dribble out) should also be installed.

Figure 12

– Thermostat Detail

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