Install Instructions

Circulator Pump Specifications
1. Maximum operating pressure for the pump must exceed
system operating pressure.
2. Maximum water temperature should not ex ceed
nameplate rating.
3. Cast iron circulators may be used for closed loop
systems.
4. A properly sized expansion tank must be in stalled near
the boiler and located on the suction side of the pump.
PUMP INSTALLATION AND MAIN TE NANCE: The boiler
circulating pump must be purchased lo cal ly. For installation
and maintenance information on the circulator pump, refer
to the pump man u fac tur ers in struc tion package included
with the pump.
4 Water connections (continued)
27
Installation & Service Manual
TO PERFORMANCE
LOOP PUMP
TO
CIRCULATION
PUMP
120V
SUPPLY
TO
UNIT
Figure 4-3_Boiler Wiring - Circulation Pump to Junction Box
Circulator Pump Operation
Boilers are equipped with a relay for controlling the circulation
pump for the hot water loop. The operating temperature
control will energize the pump relay, which energizes the
pump on a call for heat. The relay turns ON and OFF in
response to the “W1” input from the wall thermostat or zone
control. The pump will operate whenever the “W1” terminal
is energized.
On boilers with the system pump delay option, the temperature
control will de-energize the pump relay approximately 30
seconds after the call for heat ends.
The field installed boiler pump MUST NOT exceed 1 h.p. For
continuous pump operation, wire the system pump to the
120V supply. The pump should be connected at the junction
box as shown in FIG. 4-3.
See Pump Wiring for a Heating Boiler, on page 34 for
additional information.
PERFORMANCE LOOP
These units are equipped with an integral performance loop,
which is designed to provide efficiency optimization by
maintaining a constant flow through the unit’s heat exchanger
loop when building system flow is reduced. The performance
loop assembly is standard equipment and is NOT to be used as
a system or boiler pump.
NOTICE
The performance loop is dedicated to the
unit and does not affect the building’s
system or primary/secondary flow
characteristics and will not circulate the
building.
It is acceptable to remove the performance loop as long as the
following requirements are met:
1. The boiler is piped to the system in primary/secondary
fashion.
2. The system set point is 140°F or higher.
3. The boiler circulating pump is sized for the appropriate
flow through the boiler.
4. The system sensor is installed in an acceptable location
for sensing the system supply temperature.
5. If water temperature is below 140°F a low temperature
bypass must be installed, (VAL30000 - 1 1/2" LTV Valve Kit)
and follow the piping diagram in FIG. 4-5.
NOTICE
If removal of the performance loop is
necessary, consult the manufacturer for
a Solution Without a Performance Loop
(KIT30068).
 WARNING
Failure to install the system sensor can
cause operation problems such as nuisance
high limit trips.
Primary/Secondary Boiler Piping
A pri ma ry/secondary pip ing system may also be in stalled to
ensure proper boiler flow rates. Primary/sec ond ary piping is
also ideal for systems using a mixture of propylene glycol and
water. A primary/secondary piping system uses a dedicated
pump to supply flow to the boiler only. This pump is sized based
on de sired boiler flow rate, boiler head loss and head loss in the
sec ond ary system piping only. The secondary pump, in stalled
in the boiler piping, ensures a constant wa ter flow rate to the
boiler for proper operation. Boiler installation with a primary/
secondary piping sys tem can prevent noise problems caused by
low sys tem water flows. A primary/secondary piping system is
recommended on any boiler where low water flow conditions
may present an operational problem.