Circulators; Flow Switch Installation - Westinghouse 220VWH Manual

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.
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.
The expansion tank must be suitable for hot potable water systems.
Expansion Tank Sizing*
VWH Model
Heat Exchanger Volume (Gallons)
220
299 / 301
399
Table 5 - *Add Required Storage Tank Gallon Size to Heat Exchanger
Volume - 60, 80, 119, and 175 Gallon Tanks Available
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.
E. Circulators
Every VWH system requires special attention to circulator size to
overcome pressure drop through the boiler and its related piping.
All circulators installed on the VWH system must be designed for
potable water installations. Boiler pressure drop is detailed in this
manual.
Water temperature above 140
continuously. Water hardness must be between 5 and 7 grains.
Hardness above 7 grains will damage the heat exchanger and
shorten the service life of the boiler.
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.
F. Flow Switch Installation
1. Choosing the correct flow paddle.
The boiler comes with a flow switch and four flow paddles. Use the
table below to determine which paddle to use with the boiler.
VWH Model
220
299 / 301
399
N/A
Table 6 - Flow Paddle Sizing
2. Use a Phillips Head screwdriver to attach flow paddle as shown
below.
2.6
3.1
3.7
o
F requires the circulator to run
Paddle Size
H1
H2
H3
H4
3. Thread outlet combination fitting onto supply outlet of boiler using
pipe dope.
4. Thread flow switch into outlet combination fitting using pipe dope,
making certain the FLOW arrow points in the correct direction.
5. Thread relief valve into outlet combination fitting using pipe dope.
6. Thread temperature and pressure gauge into outlet combination
fitting using pipe dope.
7. Connect red wire from flow switch to boiler wire harness.
8. When installation is complete, power up the boiler and program
set point. *Please note that these illustrations are meant only
to demonstrate installation. The installer is responsible for all
equipment and detailing required by local codes.
WHL-053 Rev. 00 Rel. 003 Date 7.21.17
17