LAARS Pennant PNCV (Sizes 200, 300, 400) - Install and Operating Manual - Manual (Page 23)

LAARS Heating Systems
Page 22 Pennant 200, 300, 400 Page 23
4B.3 Water Flow Requirements —
Water Heater
In a water heating application (an open system),
new water is constantly being introduced. With the
new water comes a fresh supply of minerals that can
be deposited on the unit’s heat exchanger. This is
commonly known as scaling. The amount of minerals
will depend upon the hardness of the water. Water can
also be aggressive, and can erode metals, including
copper, if the water is moved too quickly. The water
flow requirements for the Pennant water heater are
based upon the hardness of the water. The water flow
is kept high enough to prevent scaling, but low enough
to prevent tube erosion. For extremely soft or hard
water, cupro-nickel tubes are available. Contact a
Laars representative if you have questions or concerns
about water quality.
Pump-mounted water heaters can be ordered
with standard pumps for soft or normal water or with
pumps for hard water. The pumps used are sized for
the head loss through the heater, plus 30 feet (9.1m)
of full-sized piping (same size as heater outlet) and a
normal number of fittings.
Table 9 specifies water flow rates for water
heaters, which will enable the user to size a pump. The
head loss shown is for the heater only, and the user
will need to add the head loss of the piping system to
properly size the pump.
4B.4 Combined Water Heating (potable)
and Space Heating — Water Heater
NOTE: These systems are not allowed in the
Commonwealth of Massachusetts.
Piping and components connected to this water
heater for the space heating application shall be
suitable for use with potable water.
Toxic chemicals, such as used for boiler
treatment, shall not be introduced into the potable
water used for space heating.
This water heater when used to supply potable
water shall not be connected to any heating system
or component(s) previously used with a non-potable
water heating appliance.
When the system requires water for heating at
temperatures higher than required for other uses,
an anti-scald mixing or tempering valve shall be
installed to temper the water for those uses in order
to reduce scald hazard potential.
4B.5 Freeze Protection — Water Heater
Although Pennant water heaters are design-
certified for outdoor installations, such installations
are not recommended in areas subject to freezing
temperatures, unless proper precautions are taken.
Power outage, interruption of gas supply, failure
of system components, activation of safety devices,
etc., may prevent a heater from firing. Any time a
heater is subjected to freezing conditions, and the
heater is not able to fire, and/or the water is not
able to circulate, there is a risk of freezing in the
heater or in the pipes in the system. When water
freezes, it expands. This can result in bursting of pipes
in the system, or damage to the heater, which could
result in leaking or flooding conditions.
Contact the local factory representative or Laars
for additional information.
SECTION 5.
Electrical Connections
WARNING
The appliance must be electrically grounded in
accordance with the requirements of the authority
having jurisdiction or, in the absence of such
requirements, with the latest edition of the National
Electrical Code, ANSI/NFPA 70, in the U.S. and
with latest edition of CSA C22.1 Canadian Electrical
Code, Part 1, in Canada. Do not rely on the gas
or water piping to ground the metal parts of the
boiler. Plastic pipe or dielectric unions may isolate
the boiler electrically. Service and maintenance
personnel, who work on or around the boiler, may
be standing on wet floors and could be electrocuted
by an ungrounded boiler.
Table 9. Water Flow Requirements - PNCV.
Model
(Size)
gpm ft Temp Rise °F lpm m Temp. Rise °C
S N H S N H S N H S N H S N H S N H
200 23 35 45 1.9 4.4 7.3 15 10 8 87 132 170 0.6 1.3 2.2 8 6 4
300 23 35 45 2.0 4.5 7.4 22 15 11 87 132 170 0.6 1.4 2.3 12 8 6
400 23 35 45 2.0 4.5 7.4 30 19 15 87 132 170 0.6 1.4 2.3 17 11 8
Notes:
1. S = soft water (1 to 7.5 grains hardness)
2. N = normal water (7.6 to 17 grains hardness)
3. H = hard water (more than 17 grains hardness)
4. gpm = gallons per minute, lpm = liters per minute, ft = head loss in feet, m = head loss in meters
5. Head loss is for heater's heat exchanger only