Operating instructions

20
Figure 27: Required Bypass Piping
Figure 28: Tankless Heater Piping
Figure 26: Recommended Piping for Combination
Heating and Cooling (Refrigeration) Systems
E. Alliance Indirect Water Heater (if used). Refer to
Alliance Installation, Operating and Service Instructions
for additional information.
1. Steam. See Figure 2 for tapping locations.
a. Supply and Return Piping. Connect supply
piping to Tapping "N" (1¼ NPT) and return
piping to Tapping "M" (1¼ NPT). Install zone
circulator and strainer in supply piping. Install
check valve to prevent gravity circulation of
boiler water.
b. Limit. See Figure 23. Install temperature limit
control (Honeywell L4006A or equal) in Tapping
"P" (¾ NPT). See Figure 2. Set at 180°F to
prevent steam production during non-space
heating periods.
2. Water without tankless heater. Install in same
manner as space heating zone.
F. Tankless Heater (if used). See Figure 28.
1. Install automatic tempering or mixing valve to
prevent delivery of scalding hot water to fixtures.
Higher temperature water for dishwahers and
automatic washers is possible by piping hot water
from heater prior to entering mixing valve. Install per
manufacturer's instructions.
2. Install flow regulator. Match regulator rating to
tankless heater rating. Install in cold water inlet
below and mimimum 3 feet downstream of tankless
heater inlet.
3. Install water softener in areas of hard water, this will
reduce mineral deposits which could hinder heat
transfer and delivery of hot water.
b. Set bypass and boiler supply valves to a half
throttle position to start.
c. After installation is complete, operate boiler
according to Section IX: System Start-up.
6. A hot water boiler installed above radiation level
must be provided with a low water cutoff device as
part of installation.
7. If a tankless heater coil is used, connect water lines
to ¾ NPT tappings in coil plate.