WHL-052 Rev. 4.28.16
15
D. Expansion Tank
Expansion Tank and Make-Up Water
1. Ensure that the expansion tank is sized to correctly handle
boiler and system water volume and temperature.
Undersized expansion tanks cause system water to be lost
from the relief valve, causing make-up water to be added.
Eventual boiler failure can result due to excessive make-
up water addition.
SUCH FAILURE IS NOT COVERED BY
WARRANTY.
2. The expansion tank must be located as shown in
Applications, this manual, or following recognized design
methods. See expansion tank manufacturer’s instructions for
details.
3. Connect the expansion tank to the air separator only if the
air separator is on the suction side of the circulator. Always
install the system fill connection at the same point as the
expansion tank connection to the system.
4. Most chilled water systems are piped using a closed type
expansion tank.
DIAPHRAGM (OR BLADDER) EXPANSION TANK
Always install an automatic air vent on top of the air separator
to remove residual air from the system.
Expansion tanks must be sized according to total system
volume. This includes all length of pipe, all fixtures, boilers,
etc. Failure to properly size for system expansion could result
in wasted time, money, possible property damage, serious
injury, or death.
Expansion Tank Sizing
Model
Heat Exchanger Volume (Gallons)
80
1.4
110
1.7
150
2
220
2.6
299 / 301
3.1
399
3.7
Table 2 - Expansion Tank Sizing
DO NOT
install automatic air vents on closed type expansion
tank systems. Air must remain in the system and return to the
tank to provide an air cushion. An automatic air vent would
cause air to leave the system, resulting in improper operation
of the expansion tank.
E. Circulators
Sizing Space Heat System Piping
1. See Applications in this manual. In all diagrams, the space
heating system is isolated from the boiler loop by the primary/
secondary connection.
DO NOT
use the boiler circulator in any location other than
the ones shown in this manual. The boiler circulator location
is selected to ensure adequate flow through the boiler.
Failure to comply with this caution could result in unreliable
performance and nuisance shutdowns from insufficient flow.
2. Size the piping and components in the space heating system
using recognized design methods.
F. Hydronic Piping with Circulators, Zone Valves, and
Multiple Boilers
This boiler is designed to function in a closed loop hydronic
system. We have included a temperature and pressure gauge
that allows the user to monitor the system pressure and outlet
temperature from the boiler. It is important to note that the
boiler has a minimal amount of pressure drop that must be
calculated when sizing the circulators. Unless the system has a
closed type expansion tank, each boiler installation must have
an air elimination device that will remove air from the system.
Install the boiler so the gas ignition system components
are protected from water (dripping, spraying, etc.) Allow
clearance for basic service of boiler circulator, valves and other
components.
Observe the minimum 1” clearance around all uninsulated hot
water pipes when openings around pipes are not protected by
non-combustible materials.
On a boiler installed above radiation level, some states and local
codes require a low water cut off device, which is an optional part
available through Westinghouse (Part # 7450P-904). Check with
local codes for additional requirements. If the boiler supplies hot
water to heating coils in air handler units, flow control valves or
other devices must be installed to prevent gravity circulation of
boiler water in the coils during the cooling cycle.
Chilled water medium must be piped in parallel with the boiler.
Freeze protection for new or existing systems must use glycol
that is specifically formulated for this purpose. Antifreeze must
include inhibitors that will prevent the glycol from attacking
the metallic system components. Make certain that the system
fluid is checked for the correct glycol concentration and inhibitor
level. The system should be tested at least once a year and as
recommended by the producer of the glycol solution. Allowance
should be made for the expansion of the glycol solution in the
system piping. Example: 50% by volume glycol solution expands
4.8% in volume for a temperature increase from 32
o
F to 180
o
F,
while water expands 3% with the same temperature rise.
G. Circulator Sizing
Minimum Boiler Flow Rates
Model
Minimum Flow (GPM)
80
5.3
110
7.3
150
10
220
14.6
299 / 301
20
399
26
Table 3 - Minimum Flow Rates
In addition, the heat exchanger has a minimum total water
volume that must be taken into account when sizing the
circulator. Minimum flow rates are listed in the table below.
The heat exchanger has a pressure drop that must be considered
in your system design. Refer to Table 4 for pressure drop through
the heat exchanger.
Summary of Contents for WBRE110
Page 13: ...WHL 052 Rev 4 28 16 13 Figure 5 Boiler Dimensions NOTE All Dimensions Are Approximate ...
Page 37: ...WHL 052 Rev 4 28 16 37 Figure 25 Internal Connection Diagram ...
Page 62: ...WHL 052 Rev 4 28 16 62 Figure 30 Combustion System Replacement Parts 80 220kBTU Models ...
Page 63: ...WHL 052 Rev 4 28 16 63 Figure 31 Combustion System Replacement Parts 299 399kBTU Models ...
Page 64: ...WHL 052 Rev 4 28 16 64 Figure 32 Cabinet Replacement Parts All Models ...
Page 65: ...WHL 052 Rev 4 28 16 65 Figure 33 Cabinet Replacement Parts All Models ...
