Specifications

Part number 550-100-090/0809
11
g a s -f i r e d w a t e r b o i l e r — Boiler Manual
BASIC INSTALLATION
Install water piping (continued)
Expansion tank and make-up water
Ensure expansion tank size will handle boiler and system water vol-1.
ume and temperature. Allow 3 gallons for boiler and its piping.
Undersized expansion tanks cause system water to be
lost from relief valve and make-up water to be added
through fill valve. Eventual boiler failure can result due
to excessive make-up water addition.
Tank must be located as shown in this manual, or following rec-2.
ognized design methods. See tank manufacturer’s instructions
for details. When installing air vents and expansion tanks, refer to
manufacturer’s instructions.
Connect the expansion tank to the air separator only if the separa-3.
tor 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.
Most piping drawings in this manual show diaphragm expansion 4.
tanks. See Figure 4 for piping from air separator to expansion tank
and make-up water line using a closed-type expansion tank.
Most chilled water systems are piped using a closed-type tank, as 5.
shown in Figure 51, page 51.
Diaphragm (or bladder) expansion tank
(1. Figure 4) Always install an automatic air vent on top of the air
separator to remove residual air from the system.
When using diaphragm or bladder tanks only — when the
boiler is installed above the system main piping, install
an automatic air vent in the top of the outgoing boiler
piping to prevent air pocketing.
Closed-type expansion tank
See 1. Figure 4, Alternate, for piping connections when using a closed-
type expansion tank.
Pitch any horizontal piping up towards tank 1 inch per 5 feet of 2.
piping. Connect to tank with at least ¾” piping to allow room for
air to rise.
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 its air cushion. An au-
tomatic air vent would cause air to leave system, resulting
in water-logging the expansion tank.
DO NOT use a closed-type expansion tank on a system
with a Weil-McLain PLUS water heater. The water heater
must use an automatic air vent. Operation of the auto-
matic air vent will deplete air in the piping, causing the
expansion tank to waterlog.
Figure 4 Expansion tank piping
Use at least the MINIMUM pipe size shown in
Figure 4 on all boiler loop piping (connecting boiler
to and from the primary/secondary connection,
item 9).
Use only primary/secondary piping
as shown.
Failure to follow these guidelines could
result in system problems.
MINIMUM
Boiler loop pipe size
Ultra-80, 105
Ultra-155, 230
Ultra-299, 399
1”
1¼”
1½”
See CAUTION at left.
MINIMUM
Boiler loop pipe size
Ultra-80, 105
Ultra-155, 230
Ultra-299, 399
1”
1¼”
1½”
See CAUTION at left.