tekmar 557 Thermostat Installation - Manual (Page 41)

© 2014 557_D - 09/14
41 of 52 A Watts Water Technologies Company
Air Group Operation Section G
In order to prevent heating and cooling at the same time, this thermostat can operate
together with other thermostats on a tekmarNet
® system to form an air group. On older
model thermostats the air group functionality was previously described as a cool group.
In an air group, one thermostat is assigned as the air group master. The air group master
operates the cooling equipment for the group. When operating as a air group, the air
temperature readings of all the air group member thermostats are communicated to the
air group master thermostat and an average temperature is determined. When the air
group master is in cooling operation, the air group member thermostats do not operate
the heating system for air heating.
When operating a heat pump, the 557 also has the ability to prevent air group member
thermostats from heating while the outdoor temperature is between the Warm Weather
Shut Down (WWSD) and the Radiant Floor WWSD (W1 WWSD) setting. This allows
the air system heat pump to heat the building during mild outdoor weather and avoids
heating up the radiant floor slab.
If the Set Heat Room temperature is adjusted while the air group is cooling, COOL is
flashed on the display to alert the user that the air group cooling system is presently
on and heating is not available. Once the cooling system shuts off, heating is available
if required.
Air Group
tekmarNet ® Communication
Member Member Master
Time Clock Section H
The thermostat includes a time clock that is automatically visible in the Home
menu when a programmable schedule is used. If the schedule is not used, the
user has the option to select whether the time is shown in the Home menu.
During a loss of power, the thermostat continues to keep the correct time and
date for at least 4 hours. If the power is off for more than 4 hours, the user will
need to set the time.
The thermostat supports automatic update for daylight savings time. Simply set
Daylight Save to On together with the correct day, month, and year and the time
is automatically updated each spring and fall.
When connected to a tekmarNet
® system, adjustment of the time on one thermostat
updates all connected thermostats. This option can be disabled by selecting the
Local Network Group setting to be On.