Standby Delay; Run-On; Setback; Last Stage Hold - heat-timer Mini-MOD Installation And Operation Instruction Manual

24 Heat-Timer Corp.

standby delay

Adjustable from 1min to 60min
Button: MENU/<System Settings>/<More Settings>/Standby Time
• The Standby Delay only applies to boilers in Standby Mode. See "Mode" on page 29.
• A boiler can be set to be a Standby boiler using the Stage Menu.
• A Standby boiler can only be activated after all the boilers in Auto Mode have run at 100%
modulation for the full Standby Time. A Standby boiler can never be a Lead Stage
• The full Standby Delay must always elapse regardless of what happens to the system
temperature. Therefore, shorter Standby Times will result in smoother set point operation in
extreme conditions. On the other hand, longer Standby Times may prevent a Standby boiler
from firing if the other boilers can eventually meet the load, or if the load decreases.

run-on

Adjustable from 0min to 360min
Button: MENU/<System Settings>/<More Settings>/Run-On
• The SYS relay will energize whenever the outdoor temperature is below the Outdoor Cutoff
and the Shutdown is Open or the Tstat is closed. When the Outdoor temperature rises 2°F
above the Outdoor Cutoff or the control is switched to Summer and after the last burner
relay has de-energized, the SYS relay will remain energized for the Run-On period.
• A common use for the Run-On is to control a system pump in a heating system. The extra
time helps transfer the boiler residual heat to the heating system.
• The Run-On time should be set based on the size and type of the boilers and pumps used.
In general, when setting the Run-On consult boiler and pump manufacturer.

setback

Adjustable from 0F°/0C° to 75F°/42C°
Button: MENU/<System Settings>/<More Settings>/Setback
• The Setback feature can be used to provide the Mini-MOD with a lower temperature Set
Point when less load is required.
• The lower Set Point will appear on the main display indicating this condition.
• For example, if the calculated temperature is 180°F and the Setback is 20°F, then when in
Setback, the Mini-MOD will hold a Set Point of 160°F = 180°F- 20°F.
• A typical use for Setback is to provide less system temperature to a building during the
night or on the weekends when building is not occupied, but heat is still required.
• The amount of Setback selected is subtracted from the Set Point when a Setback Input
Signal is received or the Night Time schedule setting started.
• If Setback is selected as the Shutdown/Tstat/Setback Mode (See "Shutdown/Tstat/Setback
Mode" on page 18.), the Setback will not be activated unless a Short dry-contact signal is
received on terminals (31 and 32).
• If Shutdown or Tstat is selected as the Shutdown/Tstat/Setback Mode, the Setback will be
activated only when the Night Schedule time has started.

last stage Hold

Adjustable from 0F°/0C° to 30F°/17C°
Button: MENU/<System Settings>/<More Settings>/Last Stg Hold
• The Last Stage Hold prevents short cycling of the Lead Stage during low demand periods.
• In these conditions, the system might require less output than the lowest fire of one Stage.
When the Mini-MOD brings on the Lead Stage, the Set Point is quickly exceeded, and the
Mini-MOD turns the Lead Stage off.
• To prolong the run time during this type of condition, use the Last Stage Hold setting to let
the system temperature exceed the Set Point by the number of degrees selected.
• For example, with a Set Point of 160°F and a Last Stage Hold setting of 10°F, the Lead
Stage boiler will remain on, at low modulation, until the Set Point reaches 170°F.
• In many cases, it is better to overshoot slightly than to short cycle a boiler.
• When Soft-Off is set to other than 0 seconds, the Lead Boiler will need to remain at or
exceed the Last Stage Hold for the Soft-Off period before turning off.
Default: 10min
Default: 0min
Default: 0F°/0C°
When using Soft-Off and Last
Stage Hold, the last boiler
stage will not turn off until both
parameters have elapsed. In
this case, Soft-Off will start after
the Last Stage Hold.
Default: 0F°/0C°
-- STANDBY DELAY --
10 min
[
▲ ▼
BACK
-- Run-On --
0 min
[
▲ ▼
BACK
------ SETBACK -------
0 o
F
[
▲ ▼
BACK
alert
--LAST STAGE HOLD--
0 o
F
[
▲ ▼
BACK
]
SAVE
]
SAVE
]
SAVE
\
]
SAVE