tekmar 527 Thermostat Installation - Manual (Page 13)

13 of 20 © 2011 D 527 - 12/11
Heating Operation Section A
Sequence of Operation
The thermostat operates the heating system to maintain the Set Room Heat
temperature. The H1 symbol is shown on the display when the thermostat is
heating. The heat can cycle on and off within +/- 1.5°F (1°C) of the Set Room
Heat temperature.
Freeze Protection ---------------------------------------------------- ----------------------------------------------------
The thermostat operates the heat whenever the room temperature falls below
40°F (4.5°C).
Exercising ---------------------------------------------------------- ----------------------------------------------------------
When connected to a tekmarNet ® reset 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
® reset
control with the Flushing feature turned on, the thermostat display will display the
“FLUSH” icon for the duration of the flushing operation.
Hydronic System Supply Pump --------------------------------------- ---------------------------------------
When connected to a tekmarNet ® system control, the thermostat’s Heat Supply
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 Heat Supply
Pump setting should be set to On.
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.