D 402 Installation & Operation Manual 09/10 tekmarNet®2 House Control 402 HVAC Systems Replaces: 01/10 Introduction The House Control 402 is designed to operate as part of a complete hydronic heating system with tekmarNet ®2 (tN2) thermostats. It can provide operation of two outdoor reset water temperatures such as radiant floor heating on the first temperature and baseboard or fan coil heating on the second temperature. In addition the control has Domestic Hot Water and Setpoint capabilities.
Table of Contents Installation ......................................................................2 Preparation ................................................................ 2 Physical Dimensions ................................................. 3 Installation Location .................................................. 3 Rough-In Wiring ........................................................ 3 Sizing the Transformer .............................................. 4 Control Wiring .....................
Materials Required -------------------------------------------------------------------------------------------------------------------• (2) #10 x 1” Wood Screws • (3) Wire Nuts • 18 AWG LVT Solid Wire (Low Voltage Connections) • 14 AWG Solid Wire (Line Voltage Connections) • tekmar 009K (24 V (ac) transformer with 4” x 4” junction box) • Cable or Conduit Connectors Power Required -------------------------------------------------------------------------------------------------------------------------------
Low Voltage Wiring --------------------------------------------------------------------------------------------------------------Each cable must be pulled from the equipment to the control’s plastic enclosure. All low voltage wiring connections enter the enclosure through conduit knockouts on the sides, or through the square knockouts on the rear. It is recommended to label each cable for easy identification.
Figure 1 - Connect Ground Wires Figure 2 - Connect Neutral Wires Variable Speed Pump Variable Speed Pump Pump Pump Pump DHW Pump Pump DHW Pump Pump Boil System Pump Mix System Pump Pump Boil System Pump Pump Power Source (L,N) Mix System Pump Figure 3 - Connect Line Voltage (Hot) Power Source (L,N) Pump Figure 4 - Connect Pump Line (Hot) V. S. Pump V. S.
Install The Enclosure ------------------------------------------------------------------------------------------------------------------------• Ensure that the pump wires are neatly tucked inside the electrical box. • Using 2 of the 4 holes in the back of the enclosure, securely fasten it to the electrical junction box with 2 #10 screws as shown in Figure 5.
Front Low Voltage Wiring Diagram ---------------------------------------------------------------------------------------------tekmarNet ®2 Thermostats 24 V (ac) Floating Action Actuator Com Open Close Mix Supply Sensor 082 Zone 3 C Vlv Stage 2 Mod dc/mA Boil Exp. Mix Exp.
Wiring the Outdoor Sensor 070 ------------------------------------------------------------------------------------------• Connect 18 AWG or similar wire to the two terminals provided in the enclosure and run the wires from the 070 to the control. Do not run the wires parallel to telephone or power cables. If the sensor wires are located in an area with strong sources of electromagnetic interference (EMI), shielded cable or twisted pair should be used or the wires can be run in a grounded metal conduit.
Testing the Sensor Wiring A good quality test meter capable of measuring up to 5,000 kΩ (1 kΩ = 1000 Ω) is required to measure the sensor resistance. In addition to this, the actual temperature must be measured with either a good quality digital thermometer, or if a thermometer is not available, a second sensor can be placed alongside the one to be tested and the readings compared. First measure the temperature using the thermometer and then measure the resistance of the sensor at the control.
Step 8 The DHW pump turns on for 10 seconds. Step 9 The boiler system pump turns on for 10 seconds. Step 10 During the boiler test step, zone relays 1 through 4 turn on, the mix system pump turns on, and the boil system pump turns on. The mixing device operates up to 20%. This ensures there is a location for heat to move when the boiler is turned on. • If the Boil Type is 1 Stage, the boiler stage 1 relay is closed for 10 seconds and then opened.
Applications Single Boiler, DHW Tank, Variable Speed Mixing, 4 Mix Zones A402-1 Description: The House Control 402 operates an On/Off boiler with indirect Domestic Hot Water. Mixing is performed with variable speed injection, which supplies an outdoor reset water temperature to the 4 onboard mix temperature hydronic zones. Additional zones (boiler or mix) can be added using the tN4 Expansion terminals.
Single Boiler, 2 Boiler Zones, DHW, 3 Way Mix, 4 Mix Zones A402-2 Description: The House Control 402 operates a modulating boiler with indirect Domestic Hot Water. Mixing is performed with a three-way floating action mixing valve, which supplies a reset water temperature to four mix temperature hydronic zones. Two boiler water temperature zones shown are operated by a Wiring Center through the tN4 Boil Expansion terminals.
User Interface Display Menu Field Item Field Displays the current menu Displays the name of the selected item Status Fields Displays the current status of the control’s inputs, outputs and operation.
Navigating The Display The 402 uses a simple user interface to accomplish a variety of functions. The four buttons beneath the display are used to change the menu, sort through Items, and adjust each setting as required. Menu Button -------------------------------------------------------------------------------------------------------------------------------------The menus display in the Menu Field at the top left side of the LCD.
View Menu (1 of 1) The View menu items display the current operating temperatures and status information of the system. Item Field Range Description -76 to 149°F (-60.0 to 65.0°C) OUTDOOR SECTION B, C Current outdoor air temperature as measured by the outdoor sensor. The outdoor air temperature is shared to all thermostats in the tekmarNet ® system. -22 to 266°F (-30.0 to 130.0°C) MIX SUPPLY SECTION B Current mix supply water temperature as measured by the mix supply sensor.
Adjust Menu (1 of 3) The Adjust menu items are the programmable settings used to operate the mechanical equipment. Item Field Range -60 to 45°F (-51.0 to 7.0°C) Default = 10°F (-12.0°C) ADJUST ADJUST MENU ADJUST SECTION B, C OUTDOOR DESIGN Typically set to the temperature of the coldest day Installer of the year. The outdoor air temperature used in the boiler and mixing heating curves that determine the boiler target and the mix target temperatures.
Adjust Menu (2 of 3) Item Field Range Access Description Installer BOILER DESIGN SECTION C The supply water temperature required for the boiler zones to heat the building on the typical coldest day of the year. Recommendations: High mass radiant floor = 120°F (50°C) Low mass radiant floor = 140°F (60°C) Fancoil or air handling unit = 190°F (90°C) Copper fin-tube convector = 180°F (80°C) Radiators = 160°F (70°C) Low profile baseboard = 150°F (65°C) OFF, 80 to 180°F (26.5 to 82.
Adjust Menu (3 of 3) Item Field ADJUST Range Access Description 40 to 100°F (4.5 to 38.0°C) Default = 70°F (21.0°C) Installer User SECTION I WWSD OCCUPIED The system’s Warm Weather Shut Down temperature during Occupied periods or when a schedule is not used. Installer WWSD UNOCCUPIED SECTION I The system’s Warm Weather Shut Down temperature during Unoccupied periods. Note: Item is only available when a schedule or User Switch is present on the system.
Monitor Menu (1 of 1) The Monitor menu items provide information about the system’s operation and performance. To clear any item back to default, press and hold the Up and Down buttons while viewing that item. MONITOR MENU Item Field Range Description MONITOR -76 to 149°F (-60.0 to 65.0°C) OUTDOOR HIGH Records the highest outdoor temperature since the item was last cleared. Press and hold the Up and Down buttons while viewing to reset. MONITOR -76 to 149°F (-60.0 to 65.
Toolbox Menu (1 of 1) The Toolbox Menu is a location for system information and Test functions. If any errors are present on the system, they will be located at the beginning of this menu. TOOLBOX MENU Item Field Range Description On or Off Default = Off USER TEST TESTING Begins the test routine which tests the main control’s functions. See the Testing the Control section for more details. Use the up button to turn the User Test On.
Sequence of Operation tekmarNet® System Section A ® tekmarNet is a family of products that use communication to operate the HVAC system in a comfortable and efficient manner. The House Control is the central component in a tekmarNet ® system and requires tekmarNet ® 2 (tN2) Thermostats to be directly connected to the control.
Mixing Device Type --------------------------------------------------------------------------------------------------------------The House Control can operate a mixing device such as a mixing valve or variable speed injection pump based upon one of four output signals. The device output bar graph on the display indicates the approximate position of the mixing device. Variable Speed Injection Pump A standard wet rotor circulator can be connected to the Variable Speed Pump output on the back of the control.
Section D Domestic Hot Water Tank Operation DHW Call ------------------------------------------------------------------------------------------------------------------------------------A DHW Call is required in order for the control to provide heat to a DHW tank. Once the control registers a DHW Call, it will display the “DHW” icon under Calls in the display.
DHW MODE 3 - DHW in Primary / Secondary no Priority When a DHW Call is present, the DHW pump and the boiler system pump is operated. Boiler temperature zones can turn on if required. DHW MODE 4 - DHW in Primary / Secondary with Priority When a DHW Call is present, the DHW pump and the boiler system pump is operated. All boiler temperature zones are shut off through tekmarNet ® communication to achieve DHW priority.
Section E Setpoint Operation A Setpoint Call is required in order for the control to provide heat to a setpoint load, such as a spa, pool, or snowmelt load. This can be done in two ways: Contact Closure -------------------------------------------------------A dry contact or 24 V (ac) signal is applied across the Setpoint Call terminals on the 402. When the control receives a Setpoint Call: • All Boil zones are turned off. • The Mix device is ramped down to a minimum level.
Boiler Maximum --------------------------------------------------------The 402 will operate the boiler so that the boiler supply temperature will never exceed 210°F (99.0°C). The highest allowed boiler target is the boiler design temperature + 10°F (5.5°C).
Both on-off and modulating boilers are operated with a differential. In some cases, a modulating boiler must be operated with a differential while operating at low fire because this indicates the load is smaller than the minimum modulation of the boiler. For modulating boilers, the differential no longer applies once operating the boiler above low fire.
Section I Energy Saving Features The “$aving” icon is displayed when energy is being saved. The following features reduce energy consumption. Network Schedules--------------------------------------------------Adding a schedule to a tekmarNet® system is both easy and valuable. A Timer 033 provides scheduling with up to 4 events per day for every tekmarNet® Thermostat.
Error Messages (2 of 3) Error Message Description OUTDOOR SENSOR OPEN CIRCUIT Due to an open circuit (disconnected or broken wire), the control failed to read the outdoor sensor. As a result, the control assumes an outdoor temperature of 32°F (0.0°C) and continues operation. Locate and repair the problem as described in the “Test the Sensor Wiring” section. MIX SENSOR SHORT CIRCUIT Due to a short circuit, the control failed to read the Mix supply sensor.
Error Messages (3 of 3) Error Message Description MIX DEVICE LOST (1:01 TO 1:24) Each tekmarNet ® device (thermostat, setpoint control, timer) has an address. The device with this address on the mix water temperature is no longer reporting back to the 402. The device can be located by either the address, or by going to each device in the building, checking that the LCD is on, and the tekmarNet® communication symbol is on.
Frequently Asked Questions (2 of 2) Symptom Look For... Burner symbol on LCD No central heating Boiler short cycling Corrective Action If the burner symbol is on the LCD, there is a problem with the boiler. Ensure the boiler aquastat manual limit is reset to the on position. WWSD symbol on LCD Warm Weather Shut Down (WWSD) is an energy saving feature that prevents central heating during the summer. Ensure the outdoor temperature reading is accurate and replace outdoor sensor if necessary.
Technical Data tN2 House Control 402 Boiler, DHW & Setpoint, Mixing, Four Zone Valves Literature Control Packaged weight Dimensions Enclosure Approvals Ambient conditions Power supply Control load Zone valve / floating action load Boiler stage 1, 2 relays Boiler system pump relay Mix system pump relay DHW pump relay Variable speed pump relay Pump power Setpoint and DHW calls Boil/Mix modulating output Sensors - Included Warranty D402, Q402, SB057 Microprocessor control.
