AERCO Esteem Boiler with EZ-Set Controller - Manual (Page 140)

GF-135 Esteem 399 Low NOx Boiler
Chapter 18
OMM-0089_0A Installation, Operation & Maintenance Manual Controller Operation
18.4.8 DHW Priority Timeout (Default: OFF)
Figure 18-34: DHW PRIORITY TIMEOUT Menu
DHW Priority Timeout allows the installer to enter an optional time limit that a domestic hot water
call has priority over a central heating call when DHW Priority is set to Enabled. Press the LEFT
or RIGHT buttons to adjust the DHW Priority Timeout then press the OK button to store the
setting.
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18.4.9 DHW Priority (Default: ENABLED)
Figure 18-35: DHW PRIORITY Menu
DHW Priority allows the domestic hot water priority function to be enabled or disabled. Press the
UP or down buttons to select Enabled or Disabled then press the OK button to store the setting.
• Enabled: Domestic hot water calls will have priority over a central heating call. The boiler
setpoint will be set to the domestic hot water setpoint during a domestic hot water call. The
DHW circulator will be enabled and the heating circulators will be disabled during a
domestic hot water call.
• Disabled: Domestic hot water calls will not have priority over a central heating call. The
boiler setpoint will be set to the domestic hot water setpoint when only a domestic hot water
call is present. The boiler setpoint will be set to the highest setpoint when simultaneous
domestic hot water and central heating calls are present. The DHW circulator will be
enabled during a domestic hot water call. The heating circulators will be enabled during a
central heating call.
WARNING!
Simultaneous domestic hot water and central heating calls will
result in the boiler operating at the highest target temperature when
DHW priority is set to disabled. The use of a mixing device on the
lower temperature zones may be required to protect the lower
temperature zones from damage.
Page 140 of 188 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, NY 10913 OMM-0089_0A
MC1 06/19/14 Ph.: 800-526-0288