tekmar 538 Thermostat Installation - Manual (Page 16)

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If the thermostat operates a thermal motor (wax actuator) zone valve, set the Heat
Supply Pump Delay setting to On. This provides a three minute delay to allow the
zone valve to open before the primary or mix pump is turned on.
In special applications with multiple zoning manifolds, the Heat Supply Pump setting
can be set to Off. This allows a Zone Group Pump located on the Zone Manager,
or Wiring Center to operate the pump for the manifold.
DHW Tank Priority --------------------------------------------------- ---------------------------------------------------
When a tekmarNet ® reset control is heating an indirect Domestic Hot Water (DHW)
tank, the thermostat may shut off the heating zones to allow the DHW tank to recover
quickly. This is determined by the DHW priority of the tekmarNet
® reset control.
Warm Weather Shut Down -------------------------------------------- --------------------------------------------
When the outdoor air temperature exceeds the Warm Weather Shut Down (WWSD)
setting on the tekmarNet
® reset control, the heating system is shut off.
Air Group Operation Section B
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.
In an air group, one thermostat is assigned as the air group master. The air group
master operates the cooling equipment for the group. This thermostat can be set
to be a member of the air group.
When operating as an air group, the air temperature readings of all the air group
member thermostats are communicated to the air group master and a temperature
average 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.
If the Set Room Heat temperature is adjusted
while the air group is cooling, the snowflake
icon is flashed to alert the user that the cooling
is presently on. Once the cooling shuts off,
the heating can start operation.
Air Group
Master Member Member
tekmarNet Communication
Floor Cooling Section C
The thermostat has the option to support radiant floor cooling when connected to a
heat pump control using tekmarNet
® communication. The floor cooling setting must
be set to On and the heating system must be in Warm Weather Shut Down (WWSD).
When the heat pump system control operates in cooling mode, all thermostats set for
floor cooling on the tekmarNet
® bus all activate the first stage heating contact (H1)
at the same time to allow chilled water into the system. The thermostat continues
to operate the cooling until either the room temperature reaches the Set Heat
temperature plus 3°F (Set Heat+1.5°C) or reaches a minimum temperature of 74°F.
If only a floor sensor is installed, the floor cooling setpoint is 67°F (19.5°C).