Installation manual

PART 5: BOILER PIPING (CONTINUED)
GAS-FIRED HOT WATER SUPPLY BOILER Boiler Manual
20
G. HIGH VELOCITY CIRCULATOR PUMP
Every VWH system requires special attention to
the pump size in order to overcome the pres-
sure drop through the boiler and its related pip-
ing. All circulators installed on the VWH system
must be designed for a potable water system.
Water chemistry*
Water pH between 6.0 and 8.0
1. Maintain boiler water pH between 6.0 and 8.0.
Check with litmus paper or have it chemically
analyzed by water treatment company.
2. If the pH differs from above, consult local water
treatment company for treatment needed.
Hardness less than 7 grains.
1. Consult local water treatment companies for
unusually hard water areas (above 7 grains
hardness).
Chlorine concentration less than 200 ppm
1. Using chlorinated fresh water should be
acceptable since drinking water chlorine
levels are typically less than 5 ppm.
2. Do not connect the boiler to directly heat
swimming pool or spa water.
3. Do not fill boiler or operate with water
containing chlorine in excess of 200 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 13 of this
manual).
NOTICE
Water temperature above 140 ° requires the
circulator pump to run continuously and must have a
water hardness of between 5 to 7 grains. Hardness
above 7 grains will damage the heat exchanger and
shorten the service life of the boiler.
Piping components
Water heating system piping:
Water heater system piping MUST be sized per
tech pipe requirements listed in Fig. 5-1 / 5-2.
Reducing the 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 rec-
ommended when storing domestic hot water
above 115°F.
Unions:
Field supplied: Recommended for unit servicea-
bility. DO NOT USE DIELECTRIC UNIONS!
ONLY BRASS OR STAINLESS STEEL.
Pressure relief valve:
Factory supplied on Mod Con VWH. The pres-
sure relief valve is sized to ASME specifications.
Storage tank may require additional relief valves
depending on local codes.