![background image](http://html1.mh-extra.com/html/earthlinked/hwm-18b/hwm-18b_installation-operation-and-maintenance-manual_3406167003.webp)
HWM-407CH-IOM (09/13)
Page 3
Table of Contents
1. Inspection/Pre-Installation ........................................................................................................ 5
A. Inspection ........................................................................................................................... 5
B. Pre-Installation ................................................................................................................... 6
2. General System Layout ............................................................................................................ 7
3. Applications ............................................................................................................................. 8
4. The Primary Circuit ................................................................................................................ 10
A. Plumbing .......................................................................................................................... 10
B. Antifreeze Protection ........................................................................................................ 11
C. Water Quality ................................................................................................................... 13
D. Storage Water Heater Sizing and Connections ................................................................ 14
E. Circulating Pump, Piping, Strainer and Flowmeter ........................................................... 15
F. Refrigerant Piping ............................................................................................................ 17
5. Controls and Electrical ........................................................................................................... 18
A. Hydronic Heating and Chilled Water Cooling .................................................................... 18
B. Chilled Water Cooling ....................................................................................................... 19
C. HWM Freeze Protection Thermostat ................................................................................ 21
6. Start-Up ................................................................................................................................. 22
7. Heat Exchanger Maintenance ................................................................................................ 24
8. Tools and Equipment ............................................................................................................. 28
Index
....................................................................................................................................... 29