Figure 26: Recommended Piping for Combination Heating and Cooling (Refrigeration) Systems
Figure 27: Recommended Piping for
Indirect Water Heater
5.Use boiler bypass if boiler is operated in system which has a large volume or excessive radiation where low boiler water temperatures may be encountered (i.e. converted gravity circulation system, etc.).
a.Bypass should be same size as supply and return lines with valves located in bypass and supply outlet as illustrated in Figures 25 and 25A in order to regulate water flow to maintain higher boiler water temperatures.
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
6.A hot water boiler installed above radiation level must be provided with a low water cutoff device as part of installation.
The low water cut off 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,
ahot water boiler must be full of water to operate safely (see XII. Appendix for further details) .
7.If a tankless heater coil is used, connect water lines to ¾ NPT tappings in coil plate.
E.Alliance Indirect Water Heater (if used). Refer to Alliance Installation, Operating and Service Instructions for additional information.
1.Steam. See Figure 27 for piping recommendations.
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
Figure 28: Tankless Heater Piping
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 dishwashers and automatic washers is possible by piping hot water from heater prior to entering mixing valve. Install per manufacturer's instructions.
WARNING
Install automatic mixing valve at tankless heater outlet to avoid risk of burns or scalding due to excessively hot water at fixtures.
2.Install flow regulator. Match regulator rating to tankless heater rating. Install in cold water inlet below and minimum 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.
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