Install Instructions

17
H. If boiler is connected to heating coils located in
air handling units where they may be exposed to
refrigerated air, boiler piping must be equipped with
flow control valves to prevent gravity circulation of
boiler water during operation of cooling system.
I. 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.).
Install pipe tee between circulator and boiler return
along with second tee in supply piping as shown in
Figures 7 and 8. Bypass should be same size as the
supply and return lines with valves located in bypass
and supply outlet as illustrated in Figures 7 and 8 in
order to regulate water flow to maintain higher boiler
water temperatures.
After the boiler is operational (reference System
Start-Up Section of this manual) set by-pass and boiler
supply valves to half throttle position to start. Operate
boiler until system water temperature reaches normal
operating range.
Adjust valves to provide 180° to 200°F supply water
temperature. Opening the boiler supply valve will raise
system temperature, while opening the by-pass valve
will lower system supply temperature.
J. A hot water boiler installed above radiation level
must be provided with a low water cut-off device as
part of installation.
If a low water cut-off is required, it must be mounted in
the system piping above the boiler.
The minimum safe water level of a hot water boiler is
just above the highest water containing cavity of the
boiler; that is, a hot water boiler must be full of water to
operate safely.
K. Oil, grease, and other foreign materials which
accumulate in new hot water boilers and a new or
reworked system should be boiled out, and then
thoroughly flushed. A qualified water treatment
chemical specialist should be consulted for
recommendations regarding appropriate chemical
compounds and concentrations which are compatible
with local environmental regulations.
L. After the boiler and system have been cleaned and
flushed, and before refilling the entire system, add
appropriate water treatment chemicals, if necessary, to
bring the pH between 7 and 11.
M. If it is required to perform a long term pressure
test of the hydronic system, the boiler should first be
isolated to avoid a pressure loss due to the escape of air
trapped in the boiler.
To perform a long term pressure test including the
boiler, ALL trapped air must first be removed from the
boiler.
A loss of pressure during such a test, with no visible
water leakage, is an indication that the boiler contained
trapped air.