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© 2010
D 527 - 08/10
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 /- 1.5°F (1°C) of the Set Room
Heat temperature.
Freeze Protection
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The thermostat operates the heat whenever the room temperature falls below
40°F (4.5°C).
Exercising
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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
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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
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When connected to a tekmarNet
®
reset control, the thermostat’s Supply Pump
setting affects how the primary pump or mix pump on the reset control operates.
When connected to the boiler bus, the primary pump is affected. When connected
to the mix bus, the mix system pump is affected.
If the thermostat operates a motorized zone valve or a zone pump, the Supply
Pump setting should be set to On.
If the thermostat operates a thermal motor (wax actuator) zone valve, set the Supply
Pump setting to Delay. 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 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
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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.
