Watts tekmar 289 - Schedule Features; Boost Functionality; Smart Setback Operation; Early Start Functionality

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Schedule
Boost
The boost feature is available when an indoor sensor is not
installed, and a programmable schedule is in use.
When a programmable schedule is used to lower the
building temperature at night, there is a time delay to increase
the building temperature from the Unoccupied to Occupied
temperature. The control shortens the recovery time by
determining how long the steam boiler needs to operate at
100% on time of a heating cycle and the boost can continue
through multiple heating cycles. The length of the boost is
determined by the temperature difference between Occupied
and Unoccupied and the duration of the unoccupied time
period. The Boost setting allows the installer to set the maxi-
mum amount of time that Boost can remain in effect. Boost is
shown on the system inputs screen while boost is in effect.
Building
Temperature
% On Time
Per Cycle
Occupied OccupiedUnoccupied
Setback Period Boost
Early Start
The Early Start feature is available when an indoor sensor is
installed, and a programmable schedule is in use.
When a programmable schedule is used to lower the build-
ing temperature at night, there is a time delay to increase the
building temperature from the Unoccupied to the Occupied
temperature. When early start is on, the control uses the
indoor sensor to learn the heat up rate of the building. The
control can then accurately predict when the control should
increase the heating cycle on time so that the building reaches
the Occupied temperature at the scheduled time. Optimum
Start is shown in the system inputs screen while early start is
in effect.
Optimum Start
10 P.M. 5A.M.8A.M.
Occ
70°F (21°C
)
UnOcc
65°F (18°C
)
Room
Temp.
Recovery Period
Optimum
Start
Setback
Period
Smart Setback
When the heating cycle reaches 85% on time, the Smart
Setback feature prevents the programmable schedule
Unoccupied period from going into effect to avoid long recovery
times. If the control is already using unoccupied setpoints
and the outdoor temperature drops so that the heating cycle
on time exceeds 85%, the control will switch to using the
occupied setpoints.
When Smart Setback is off, the control continues to operate
on the occupied/unoccupied programmable schedule, regardless
of the heating cycle on time.