Tekmar tekmarNet 2 House Control 406 Installation & Operation Manual page 38

DHW MODE 1 - DHW in Parallel no Priority
When a DHW Call is present, the DHW Pump is activated.
The Boiler System Pump does not turn on, but may operate
based on either a Boiler, Setpoint or Backup Call.
It is assumed that the DHW Pump will provide adequate flow
through the heat exchanger and the boiler.
DHW Mode = 1
DHW MODE 2 - DHW in Parallel with Priority
When a DHW Call is present, the DHW Pump is activated.
The Boiler System Pump and all boiler temperature zones
are shut off through tekmarNet
DHW priority.
It is assumed that the DHW Pump will provide adequate flow
through the heat exchanger and the boiler.
DHW Mode = 2
DHW MODE 3 - DHW in Primary / Secondary no Priority
When a DHW Call is present, the DHW Pump and the Boiler
System Pump are operated. Boiler temperature zones can
turn on if required.
DHW Mode = 3
Boiler System
Pump
ON
© 2011 D 406 - 12/11
Zone
DHW
Pump
Pump
ON
ON
Or
OFF
Boiler
Pump
ON Or OFF
® communication to achieve
DHW Zone
Pump Pump
ON OFF
Boiler
Pump
OFF
Zone
Pump
ON
DHW
Or
Pump
OFF
ON
DHW MODE 4 - DHW in Primary / Secondary with Priority
When a DHW Call is present, the DHW Pump and the Boiler
System Pump are operated. All boiler temperature zones are
shut off through tekmarNet
priority.
DHW Mode 5 - DHW Pre-Heat with Priority
DHW Mode 5 may be used in electric only systems where the
heat pump provides heat to a DHW preheat tank. This mode
is only available when the WATERTEMP setting in the Adjust
Menu is set to tank (T).
The DHW sensor is located inside the preheat tank and targets
a 90°F (32°C) tank temperature by default. No other DHW call
is accepted. Use the DHW OCC setting in the Adjust Menu to
adjust the preheat tank target.
The heat pump will target a water temperature 20°F (11°C)
higher than the preheat tank target at the return sensor. The
heat pump target is limited by the HP RETURN MAX setting
in the Adjust Menu.
When a DHW Call is present from the DHW Sensor, the DHW
Pump is activated. The HP Loop Pump is shut off while zones
on the tank bus are allowed to continue to call for heat. This
prioritizes DHW preheat while allowing tank zones to use any
available heat in the storage tank.
It is assumed that the DHW Pump will provide adequate flow
through the preheat tank and the heat pump.
Note: DHW pre-heat will not occur when there is a cooling
call on the Tank bus.
Cold In
HP Return
Sensor
38 of 48
® communication to achieve DHW
DHW Mode = 4
Zone
Pump
DHW
OFF
Pump
ON
Boiler System
Pump
ON
DHW Mode = 5
DHW Preheat
Tank
DHW
Sensor
Electric
Water
Heater
DHW
Pump
ON
Storage
HP Loop
Tank
Pump
OFF
Hot Out
Tank System
Pump
OFF
Expansion
Tank