Install Instructions

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X. Operation F. Changing Adjustable Parameters (continued)
“Press”
Domestic
Hot Water
button to access the following parameters:
Factory
Setting
Range / Choices Parameter and Description
170°F
(76.7°C)
60°F (16°C) to
190°F
(26.7°C to 87.8°C)
Domestic Hot Water Setpoint
The Domestic Hot Water (DHW) Setpoint parameter is used to create a minimum
boiler water temperature setpoint that is used when DHW heat demand is “on”.
When the DHW heat demand is not “on” (the contact is
open or not wired) this setpoint is ignored.
160°F
(71.1°C)
60°F (16°C) to
190°F
(26.7°C to 87.8°C)
Domestic Hot Water Thermostat “Sleep” or “Away” Setback Setpoint
Thermostat setback setpoint is used when the EnviraCOM thermostat is in “leave” or
“sleep” modes and sensed at E-COM terminals D, R, and C. When setback is “on” the
thermostat setback setpoint shifts the DHW setpoint to lower the DHW temperature
and to save energy while home is in a reduced room temperature mode.
7°F
(3.9°C)
2°F to 10°F
(1.1°C to 5.6°C)
Domestic Hot Water Diff Above
The boiler stops when the water temperature rises ‘Diff Above’ degrees above the setpoint.
5°F
(2.8°C)
2°F to 25°F
(1.1°C to 14°C)
Domestic Hot Water Diff Below
The boiler starts when the water temperature drops ‘Diff Below’ degrees below the setpoint.
3 1 to 5
Response Speed
This parameter adjusts the Domestic Hot Water temperature controller Proportion Integral
Derivative (PID) values. Higher values cause a larger ring rate change for each degree of
temperature change. If set too high ring rate “overshoots” required value, increases to high re
causing the temperature to exceed the “Diff Above” setpoint and cycle the boiler unnecessarily.
Lower values cause a smaller ring rate change for each degree of temperature change. If set
too low, the ring rate response will be sluggish and temperature will wander away from setpoint.
10
seconds
0 to 300 seconds
Low Fire Hold Time
“Low Fire Hold Time” is the number of seconds the control will wait at low re modulation rate
before being released to modulate. After ignition and ame stabilization periods the ring rate is
held at low re for “Low Fire Hold Time”. This delay allows heat to travel out to the indirect water
heater and provide feedback prior to the control modulating ring rate.
Enabled Enable, Disable
Domestic Hot Water Priority (DHWP)
When Domestic Hot Water Priority is Enabled and Domestic Hot Water (DHW) heat demand
is “on” the DHW demand will take “Priority” over home heating demand. When the System
and Boiler pumps are congured as “Central Heat (off DHW priority)” or “Central Heat,
Optional Priority” then they will be forced “off” during DHW Priority. Priority protection time
is provided to end DHWP in the event of a failed or excessive long DHW demand.
60 30 to 120 Minutes
Priority Time
When DHWP is Enabled the Priority Time Parameter appears and is adjustable.
DHW
Terminal
DHW Terminal,
Zone Control
Domestic Demand Source
The Control’s “DHW Temp Switch” input terminal may be used as a DHW demand or Auxiliary
Heat demand. When “DHW Terminal” is selected the Control will accept a DHW input from
either the “DHW Temp Switch” or the Zone Control (zone 4, set to priority). If “Zone Control”
is selected the Control can only accept the DHW input from the Zone Control. This allows
the Control to be set to accept an Auxiliary heat demand from the “DHW Temp Switch”
input terminal. Refer to the Auxiliary heat menu for required selection to use this input.
DHW Terminal DHW demand may be wired to the DHW Switch terminal or Zone Control.
Zone Control DHW demand may only be wired to the Zone Control.