Lochinvar Harmony - Manual (Page 26)

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• In a new installation, start with an Offset value of 0°.
• Adjust the Offset value in mild weather. If the ambient indoor
temperatures are warm in the warm weather, decrease the Offset. If
the ambient building temperatures are cold in the mild weather,
increase the Offset.
• The rule of thumb for baseboard radiation is to change the Offset by
4° for every degree you wish to change the building temperatures.
For radiant heat applications, change the Offset by 1° or 2° for every
degree you wish to change the building temperature.
• The Offset can be set from -50 to 50°F.
OUTDOOR CUTOFF Default 64°F
• The Outdoor Cutoff sets at what outdoor temperature the Harmony
will begin heating.
• When the outdoor temperature is above the Outdoor Cutoff tem-
perature, the Harmony will not activate stages. The Set Point water
temperature will read Off.
• When the outdoor temperature drops to the Outdoor Cutoff tem-
perature, the Harmony will activate the SYS relay, compute the Set
Point water temperature, and sequence and modulate Stages to hold
that Set Point.
• The Outdoor Cutoff has a built in 2°F differential. Once the SYS relay
has been activated, it will remain activated until the outdoor tempera-
ture rises to 2°F above the Outdoor Cutoff temperature.
• If the building is too cold before the system starts, raise the Outdoor
Cutoff temperature.
• The Outdoor Cutoff temperature can be set Off, On, or from 30 to
75°F.
• Setting the Outdoor Cutoff to Off may be used to disable the heating
system during summer, during maintenance, or whenever no heat is
required for a prolonged period of time regardless of outdoor
temperature.
• Setting the Outdoor Cutoff to On means the heating system will run
regardless of outdoor temperature. In mild weather, the lowest
calculated Set Point will be determined by the Minimum Water
Temperature (next).
MINIMUM WATER TEMPERATURE Default 70°F
• Most boilers require a minimum temperature for the water returning
from the system to the boiler.
• The Harmony controls the system temperature which is measured at
the sensor location. Depending on the piping configuration and
sensor location, the return temperature may vary significantly from
that measured by the Harmony.
• Check with the manufacturer for the appropriate Minimum Water
Temperature setting at the Harmony's sensor to meet the boiler's
requirements.
• The Harmony will use the Minimum Water Temperature as the Set
Point whenever it is higher than the calculated value determined by
the outdoor temperature, Reset Ratio, and Offset.
• The Minimum Water Temperature can be set from 70 to 180°F.
IMPORTANT: If the Minimum Water Temperature is not set correctly,
boiler life may be significantly shortened.
--- RESET RATIO ---
1.00°OD = 1.50°Sys
>1.00°OD = 1.25°Sys
1.00°OD = 1.00°Sys
----- OFFSET ----
Value
----- OFFSET ----
Value -> New Value
PRESS TO SELECT
ADJUST
After
selecting
Ratio
PRESS TO SELECT
ADJUST
Turn to
adjust
Offset
PRESS TO SELECT
ADJUST
Press to
select
new
----- OFFSET ----
Value -> New Value
-- OUTDOOR CUTOFF --
Value
-- OUTDOOR CUTOFF --
Value -> New Value
PRESS TO SELECT
ADJUST
After
selecting
Offset
PRESS TO SELECT
ADJUST
Turn to
adjust
Cutoff
PRESS TO SELECT
ADJUST
Press to
select
new
-- OUTDOOR CUTOFF --
Value -> New Value
-MINIMUM WATER TEMP-
Value
-MINIMUM WATER TEMP-
Value -> New Value
PRESS TO SELECT
ADJUST
After
selecting
Cutoff
PRESS TO SELECT
ADJUST
Turn to
adjust
Minimum
PRESS TO SELECT
ADJUST
Press to
select
new
RESET SETTINGSRESET SETTINGSRESET SETTINGSRESET SETTINGSRESET SETTINGS