HTP EL-399NVWH - Manual (Page 21)

21
LP- 346 REV. 3.20.14
Water temperature above 140
o
F requires the circulator pump to run continuously and must have a water hardness of between 5 and 7
grains. Hardness above 7 grains will damage the heat exchanger and shorten the service life of the heater.
Water chemistry*
Sodium less than 20 mGL
Water pH between 6.0 and 8.0

Maintain heater water pH between 6.0 and 8.0. Check with litmus paper or have it chemically analyzed by a water treatment
company.

If the pH differs from above, consult local water treatment company for treatment needed.
Hardness less than 7 grains
Consult local water treatment companies for unusually hard water areas (above 7 grains hardness).
Chlorine concentration less than 100 ppm

Using chlorinated fresh water should be acceptable since drinking water chlorine levels are typically less than 5 ppm.

Do not connect the heater to directly heat swimming pool or spa water.

Do not fill heater or operate with water containing chlorine in excess of 100 ppm.
*NOTE: It is recommended you clean heat exchanger at least once a year to prevent lime scale buildup. Follow the
maintenance procedure to clean the heat exchanger in the Maintenance Section (Part 12 of this manual).
Hardness: 7 grains
Chloride levels: 100 ppm
pH levels: 6-8
TDS: 2000 ppm
Sodium: 20 mGL
Piping components
Water heating system piping:
Water heater system piping MUST be sized per technical pipe requirements listed in Table 9 and Table 10. Reducing pipe size can
restrict flow rate through the water heater, causing inadvertent short cycling and poor system performance.
Check valves:
Field supplied. Check valves are recommended for installation as shown in Piping Details.
Water heater isolation valves:
Field supplied. Full port ball valves are required. Failure to use full port ball valves could result in a restricted flow rate through the water
heater.
Anti-scald mixing valve:
Field supplied. An anti-scald mixing valve is recommended when storing domestic hot water above 115°F.
Unions:
Field supplied: Recommended for unit serviceability. DO NOT USE DIELECTRIC UNIONS!
ONLY BRASS, COPPER, OR STAINLESS STEEL.
Pressure relief valve:
Factory supplied on Heater. The pressure relief valve is sized to ASME specifications. Storage tank may require additional relief valves
depending on local codes.
MINIMUM VWH PIPE SIZES
EL-80/110/150/220 VWH 1” NPT or Copper
EL-299/301 VWH 1 ¼” NPT or Copper
EL-399 VWH 1 ½” NPT or Copper
Table 11
I. PIPING
The heater is designed to function in an open loop hot water supply system. We have included a temperature and pressure gauge that
allows the user to monitor the system pressure and outlet temperature from the heater. It is important to note that the heater has a
minimal amount of pressure drop and must be calculated when sizing the circulators.