Outdoor Cutoff Temperature; Offset; Minimum Water Temp - heat-timer Mini-Extension Installation And Operations

will only be 125°F, and at 24°F outside, the system water will be 112°F. Such a low Reset
Ratio might be used with radiant floor heating applications.
• With most baseboard heating applications, a 1.00 (OD):1.00 (SYS) setting is a good
place to start. With a 1.00 (OD):1.00 (SYS) ratio, for every degree the outside
temperature falls, the system water temperature is increased one degree.
• If required: Adjust the RESET RATIO in cold weather. If the ambient building
temperatures are too cold in cold weather, move the ratio to a higher selection. That is,
if 1.00 (OD):1.00 (SYS) was initially selected, change the selection to 1.00 (OD):1.25
(SYS). If the building temperatures are too warm in cold weather, move the ratio to
a lower selection. That is, if 1.00 (OD):1.00 (SYS) was initially selected, change the
selection to 1.25 (OD):1.00 (SYS).

OUTDOOR CUTOFF TEMPERATURE

Adjustable Off, 20ºF - 100ºF, On
Button: MENU/Set Point/Outdoor Cutoff
Button: MENU/Set Point/Offset/Outdoor Cutoff
• If the outdoor sensor is installed, the Outdoor Cutoff screen will automatically appear
after the temperature Set Point has been selected.
• When the outdoor temperature falls to the adjustable Outdoor Cutoff temperature, the
Mini-MOD will control and modulate Boilers to hold the calculated temperature.
• When the outdoor temperature rises to the Outdoor Cutoff plus a 2°F differential, the Mini-MOD will turn all boilers off. The
System relay will remain energized for the Run-On delay then de-energize.
• The Outdoor Cutoff can be set from 20°F to 100°F. In addition, the Setting can be set to ON or OFF. In the ON position, the
System Relay will run regardless of the Outdoor temperature (OD) and the burner stages will be active to hold the calculated
water temperature. (Note: The lowest water temperature the Mini-MOD will circulate is 70°F. If the Outdoor Cutoff is turned
ON and the Season is set to Winter, the Mini-MOD will circulate at least 70°F water even in the hottest of weather.) In the OFF
position, the system pump will always be off and all burner stages will be off.

OFFSET

Adjustable 50ºF - (-50ºF)
Button: MENU/Set Point/Offset
• The Offset setting lets you adjust the starting points of the Reset Ratio curves. This
means that, regardless of the Outdoor temperature (OD), or the Reset Ratio that has
been selected, when the Offset setting is changed, that change is directly added to or
subtracted from the calculated temperature. For example, if the Set Point temperature
was 130°F and the Offset was changed from 0° to 10° (an increase of 10°), then the Set
Point temperature would increase to 140°F
• The Offset setting does not change the ratio selection. For instance, with 1.00 (OD):1.00 (SYS) Reset Ratio, the System water
temperature (SYS) will always increase one degree for each degree change in the Outdoor temperature (OD). What the Offset
does is add or subtract a constant temperature value. (See Understanding Operation Concept)
• If required: Adjust the Water Offset in mild weather. If the ambient building temperatures are too warm in the mild weather,
decrease the Water Offset. If the ambient building temperatures are too cold in the mild weather, increase the Water Offset. The
rule of thumb for baseboard radiation is to change the Offset 4°F for every 1°F you wish to change the building temperatures.
In radiant heat applications, change the Offset 1°F or 2°F for every 1°F you wish to change the building temperature.

MINIMUM WATER TEMP

Adjustable 70ºF - 180ºF
Button: MENU/Set Point/Offset/Outdoor Cutoff/Minimum Water Temp
• The Minimum Water Temperature must be set to the boiler manufacturer's specification.
The Mini-MOD will calculate the Set Point based on the Outdoor temperature (OD), the
Reset Ratio, and the Offset value. The Mini-MOD will control all boilers modulation to
hold either the Set Point temperature, or the Minimum Water Temperature, whichever is higher.
• The Minimum Water Temperature must be at least 20°F lower than the Maximum Temperature (See next setting).
Mini-MOD & Mini-Extension Installation Manual
Default: 65ºF
in Set Point
in Reset
Default: 0ºF
in Reset only
Default: 70ºF
in Reset only
1:4
130
Warmer
120
Colder
110
100
70 60 50
Outdoor Temperature
------- OUTDOOR CUTOFF -------
65
F
[]
BACK
-------------- OFFSET -------------
+0
F
[]
BACK
--- MINIMUM WATER TEMP ----
70
F
[]
BACK
17
1:1
4:1
40
SAVE
SAVE
SAVE