tekmar 552 Thermostat Installation - Manual (Page 30)

© 2014 552_D - 09/14
30 of 44 A Watts Water Technologies Company
Freeze Protection ---------------------------------------------------- ----------------------------------------------------
The thermostat operates the heat whenever the room or floor temperature falls
below 40°F (4.5°C) even when the mode is set to off.
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.