tekmar 557 Thermostat Installation - Manual (Page 37)

© 2014 557_D - 09/14
37 of 52 A Watts Water Technologies Company
Room Min and Max Limits Section C
Heating and cooling minimum and maximum temperature settings are available in the Set
Temp menu. These allow the installer to select start and stop limits for the temperature
settings in both heating and cooling for the User and Limited access levels. This is
useful in commercial installations and child / guest bedrooms where availability of the
full temperature setting range may not be desirable.
Hydronic Pump and Valve Operation Section D
Exercising ---------------------------------------------------------- ----------------------------------------------------------
When connected to a tekmarNet ® system control, the thermostat exercises the heat relay for
10 seconds every 3 days. Exercising helps prevent zone valves or zone pumps from failing
due to precipitate buildup. During exercising, the thermostat shows “TEST” on the display.
Flushing ------------------------------------------------------------ ------------------------------------------------------------
The flushing feature is for open-loop systems that use a domestic hot water tank as a
heat source. Flushing ensures that fresh potable water is circulated through the system
once each day. If the thermostat is connected to a tekmarNet
® system control with the
Flushing feature turned on, the thermostat display will display “FLUSHING” for the
duration of the flushing operation.
Hydronic System Supply Pump --------------------------------------- ---------------------------------------
When connected to a tekmarNet ® system control, the thermostat’s W1 Pump setting
affects how the primary pump or mix pump on the system control operates. When
connected to the boiler bus, the boiler system or primary pump is operated. When
connected to the mix bus, the mix system pump is operated.
If the thermostat operates a motorized or thermal motor zone valve, the W1 Pump
setting should be set to On.
If the thermostat operates a thermal motor (wax actuator) zone valve, set the W1 Thermal
Motor 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 W1 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 ® system 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
® system control.