D 401 Installation & Operation Manual 07/11 tekmarNet® 2 House Control 401 HVAC Systems Replaces: 09/10 Introduction The House Control 401 is designed to operate as part of a complete hydronic heating system with tekmarNet ®2 (tN2) thermostats. It can provide operation of a single outdoor reset water temperature, Domestic Hot Water and Setpoint capabilities. It is easy to add more zones, add schedules or other convenient accessories through the use of the tekmarNet ®4 (tN4) Expansion terminals.
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.
Rear Line Voltage Wiring Diagram --------------------------------------------------------------------------------------------(black) DHW (black) 401 Zone 4 Zone 3 Zone 4 (black) Zone 3 (black) Zone 2 Zone 2 DHW Pump Zone 1 (black) Pump Power (red) Strip wires 1/2 inch (13 mm). Installed wires are not removable.
Front Low Voltage Wiring Diagram -------------------------------------------------------------------------------------------------tekmarNet ®2 Thermostats Made in Canada tN2 tN2 tN2 tN2 tN2 tN2 tN2 tN2 Zone 1 Zone 2 Zone 3 Zone 4 Stage 2 Mod dc/mA Boil Exp.
Wiring the Outdoor Sensor ---------------------------------------------------------------------------------------------• Connect 18 AWG or similar wire to the two terminals provided in the enclosure and run the wires from the sensor 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.
• If the Boil Type is 1 Stage, the boiler stage 1 relay is closed for 10 seconds and then opened. • If the Boil Type is 2 Stage, the boiler stage 1 relay is closed for 10 seconds, then the boiler stage 2 relay is closed for 10 seconds and then both relays are opened. • If Boiler Type is modulating 0 - 10, the boiler stage 1 relay is closed for 10 seconds and the modulating output operates at 50 % [5 V (dc)].
Applications Single Boiler, DHW Tank, 4 Boiler Zones A401-1 Description: The House Control 401 operates an On/Off boiler with indirect Domestic Hot Water. The boiler is operated using Outdoor Reset with Indoor Feedback. This supplies the lowest water temperature to the 4 onboard hydronic zones, while maintaining comfort in the building. Additional zones can be added using the tN4 Expansion terminals.
Single Boiler, DHW Tank, 8 Boiler Zones A401-2 Description: The House Control 401 operates a modulating boiler, and indirect Domestic Hot Water tank and four onboard hydronic zones. The boiler is operated using Outdoor Reset with Indoor Feedback. Four additional 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 401 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 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) BOILER SUPPLY SECTION B Current boiler supply water temperature as measured by the boiler sensor.
Adjust Menu (1 of 2) 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 sec ADJUST MENU Set to OUTDOOR DESIGN SECTION B Typically set to the temperature of the coldest day of Installer the year. The outdoor air temperature is used by the boiler heating curve to determine the boiler target temperature.
Adjust Menu (2 of 2) Item Field Range ADJUST sec ADJUST Access Description 0 to 3:00 minutes Default = 10 seconds Installer SECTION E MODULATION DELAY Delay time between the burner firing and the boiler releasing to modulation. Note: This item is only available when the Boiler Type is 0-10 V (dc) or 4-20 mA. 40 to 100°F (4.5 to 38.0°C) Default = 70°F (21.
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.
Section C 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 5 - DHW in Near Boiler Piping with Priority DHW Mode 5 requires that a DHW sensor be located on the boiler outlet pipe and a DHW call from an aquastat inside the DHW tank. The aquastat operates the DHW tank temperature while the DHW sensor is used to control the boiler temperature delivered to the DHW indirect heat exchanger. When a DHW Call is present, the DHW pump is activated. All boiler temperature zones are shut off through tekmarNet® communication to achieve DHW priority.
Section D 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 401. When the control receives a Setpoint Call: • All boiler temperature zones are turned off.
Boiler Maximum --------------------------------------------------------The 401 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.
Troubleshooting It is recommended to complete all wiring to ensure trouble free operation. Should an error occur, simply follow these steps: 1. Find: If the House Control or tekmarNet ® Thermostat flashes on the screen, it is indicating a problem on the system. 2. Identify: Use the Menu button to locate the Toolbox Menu. The Error code should appear as the first item. 3. Solve: Using the lookup chart below, match the Error code to the one on the control.
Error Messages (2 of 2) Error Message Description BOILER DEVICE LOST (b:01 TO b:24) Each tekmarNet ® device (thermostat, setpoint control, timer) has an address. The device with this address on the boiler water temperature is no longer reporting back to the 401. 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... Fuse holder LCD display is off No central heating Corrective Action Control power supply has a 24 V (ac) fuse which if blown, requires replacement. Power to control Use electrical meter to measure 24 V (ac) voltage on input power R and C terminals. Burner symbol on LCD 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.
Technical Data tN2 House Control 401 Boiler, DHW & Setpoint, Four Zone Pumps Literature Control Packaged weight Dimensions Enclosure Approvals Ambient conditions Power supply Control load Boiler stage 1, 2 relays Zone 1 to 4 pump relays DHW pump relay Pump power Setpoint and DHW calls Boiler modulating output Sensors - Included Warranty D401, Q401 Microprocessor control. This is not a safety (limit) control. 1.4 lbs (640 g) 5.5” H x 5.5” W x 2.
