Force FORCEOL Series, Installation, Operating And Service Instructions, Page: 17 / 72

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A. EVALUATE THE EXISTING WATER
SYSTEM.
Design a piping system and install boiler which will
prevent oxygen contamination of boiler water and
frequent water additions.
1. There are many possible causes of oxygen
contamination such as:
a. Addition of excessive make-up water as a result
of system leaks.
b. Absorption through open tanks and fittings.
c. Oxygen permeable materials in the distribution
system.
2. In order to insure long product life, oxygen sources
must be eliminated. This can be accomplished by
taking the following measures:
a. Repairing system leaks to eliminate the need for
addition of make-up water.
b. Eliminating open tanks from the system.
c. Eliminating and/or repairing fittings which allow
oxygen absorption.
d. Use of non-permeable materials in the
distribution system.
e. Isolating the boiler from the system water by
installing a heat exchanger.
WARNING
System supply and return piping must be
connected to correct boiler manifolds.
U.S. Boiler Company, Inc. recommends sizing
the system circulator to supply sufficient
flow (GPM) to allow a 20°F temperature
differential in the system. When sizing the
system circulator, the most restrictive single
zone should be used to determine maximum
pressure drop.
CAUTION
Maintain minimum ½ inch clearance from hot
water piping to combustible materials.
3. In order to insure long product life, operate boiler at
appropriate flow rate to minimize areas of overheating
.
a. Design system to ensure that the flow is above the
limit called for in Table 4.
b. Maintain a constant boiler pressure of 12 PSI.
WARNING
Do not operate boiler below minimum volumetric
flow rates.
B. CONNECT SYSTEM SUPPLY AND RETURN
PIPING TO BOILER. See Figures 10A and 10B.
Also, consult Residential Hydronic Heating Installation
and Design I=B=R guide.
1. If this boiler is used in connection with refrigeration
systems, the boiler must be installed so that the chilled
medium is piped in parallel with the heating boiler
using appropriate valves to prevent the chilled medium
from entering the boiler. See Figure 11. Also, consult
Residential Hydronic Heating Installation and Design
I=B=R guide.
2. If this boiler is connected to heating coils located
in air handling units where they may be exposed to
refrigerated air, the boiler piping must be equipped
with flow control valves to prevent gravity circulation
of boiler water during the operation of the cooling
system.
3. If an indirect water heater is used, priority zoning can
be used. Do not use priority zoning for Hydro-Air
Systems. Refer to the Indirect Water Heater Installation,
Operating, and Service Instructions for additional
information.
4. The FORCEOL is designed to withstand thermal shock
from return water temperatures as low as 100°F, but
prolonged return temperatures of below 135°F can
cause excessive flue gas condensation and damage
the boiler and/or venting system.
Use a boiler bypass if the boiler is to be operated
in a system which has a large volume or excessive
radiation where low boiler water temperatures may be
encountered (i.e. converted gravity circulation system,
etc.) The bypass should be the same size as the supply
and return lines with valves located in the bypass and
return line as illustrated in Figures 10A and 10B in
order to regulate water flow for maintenance of higher
boiler water temperature.
IV: WATER BOILER PIPING
NOTICE
Failure to pipe boiler as specified in this manual may result in excessive system noise.
Boiler Model No. Flow Rate (Gal / Min)
FORCEOL084 4.5
FORCEOL115 6.0
FORCEOL147 8.0
FORCEOL189 10.0
TABLE 4: MINIMUM FLOW RATE