Part number 550-143-010/1021
59
GV90+
series
2
gas-fired water boiler – boiler manual
Eliminate all system leaks. Continual fresh makeup
water will reduce boiler life. Minerals can build up
in sections, reducing heat transfer, overheating cast
iron, and causing section failure.
Clean system to remove sediment
1. You must thoroughly flush the system (without boiler con-
nected) to remove sediment. Sediment can affect chemical
treatment of the system and can damage system components.
2. For zoned systems, flush each zone separately through a purge
valve. (If purge valves and isolation valves are not already
installed, install them to properly clean the system.)
3. Flush system until water runs clean and you are sure piping
is free of sediment.
Water chemistry
Softened water maybe used to fill boiler providing
Sentinel X100 is added to the system at the proper
dosage and properly maintained. Without Sentinel
X100, softened water
must not
be used or boiler
corrosion may occur.
Water chemistry must be within the limits
listed in the following
. If the water differs in any
way, consult a water treatment company to set up
a treatment program to control the system water
within these limits at the time of initial fill and
throughout system operating life.
Failure to maintain water chemistry as specified
can result in damage to the boiler and system com-
ponents, resulting in potential for severe personal
injury, death or substantial property damage.
Water pH:
Minimum = 7.0 | Maximum = 8.5
Maintain boiler water pH between 7.0 and 8.5. Check with litmus
paper or have chemically analyzed by water treatment company.
Hardness: Maximum = 6.0 grains per gallon
The water hardness must comply with the maximum value above.
High hardness will cause scale accumulation.
Chlorine:
Maximum 200 ppm
1. Filling with chlorinated fresh water should be acceptable since
drinking water chlorine levels are typically less than 5 ppm.
2. Do not use 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.
Antifreeze
1. Use only antifreeze listed by Weil-McLain as suitable for use
with GV90+ boilers.
Figure 70
Freeze protection guidelines
Freeze protection (when used)
Follow these guidelines to prevent possibility of
severe personal injury, death or substantial prop-
erty damage:
NEVER use automotive or standard glycol anti-
freeze
,
even glycol made for hydronic systems
.
Use only freeze-prevention fluids recommended
by Weil-McLain for application in GV90+ Boiler
systems.
Thoroughly flush any system that has used
glycol
before installing the new GV90+ boiler.
Review the material safety data sheet (MSDS)
for the fluid used with the boiler owner and leave
a copy for reference. The MSDS contains informa-
tion on potential hazards and first aid procedures
for exposure or ingestion.
Check antifreeze inhibitor level at least annu-
ally
. Glycol concentration and inhibitor levels may
change over time. Add antifreeze to increase con-
centration if necessary. Add inhibitor as needed to
bring to acceptable level, using inhibitor test kit to
verify.
When using freeze protection fluid with auto-
matic fill,
install a water meter to monitor water
make-up
. Freeze protection fluid may leak before
the water begins to leak, causing concentration to
drop, reducing the freeze protection level.
DO NOT exceed 50% antifreeze by volume
.
Antifreeze moves more sluggishly than water and
can interfere with heat transfer. At antifreeze con-
centrations higher than 50%, sludge can develop
in the boiler, potentially causing damage to the
heat exchanger.
Clean the system before filling
. Always drain
and flush the system thoroughly before filling with
antifreeze. Sludge, iron oxide deposits and other
sediment in the system inhibit flow and can cause
rapid breakdown of inhibitors.
TSTAT/CIRC light flashing alone
Usually indicates return water temperature sensor
detects water at boiler return pipe less than 40°F.
Both internal circulators will run continuously,
even with no call for heat, until temperature rises.
Start-up
