Technical Service Bulletin

Title:  Thermostat operation with Vitotronic 300-K

Applies to: 
▪  Vitotronic 300-K, MW2C Cascade Control

Vitotronic 300-K, MW2C

Important Disclaimer

The information in this bulletin is intended exclusively for licensed heating contractors, and is NOT intended for the end user. This material is NOT intended to take the place of the information contained in the manuals shipped with the product.

Use of this information by unqualified personnel may result in property damage, personal injury or death.

End users are asked to contact a qualified contractor for all installation and service work. If you need assistance finding a contractor in your area, contact your Viessmann Sales Representative, or use our Contractor Locator.

By hitting "Yes" below you confirm that you have read, understood and agree to this warning, that you are licensed and hold the current, appropriate licences to work on said equipment in the location and/or jurisdiction of installation.


How to program the Vitotronic 300-K to operate with a thermostat



Due to market demand for operating the Vitotronic 300-K, MW2C cascade control with a dry contact thermostat while utilizing outdoor reset logic, we are providing the necessary programming changes to allow for this using the instructions below.

Requirement:  An EA1 Extension Module must be connected to the Vitotronic 300-K, MW2C cascade control in order to use these instructions.


Instructions:

1. Go into Coding Level 2 on the control. To do this, tap the Menu button on the home screen, and then the Service button. When prompted for a password, enter "viservice". From the Service menu, tap the System Configuration button, and then the Coding Level 2 button. When prompted for a password, enter "viexpert".

2. Tap the General button.

3. Set the value at coding address "5D" to "1". This setting activates the DE1 contact.

4. Return to the Coding Level 2 menu, and then tap the Heating Circuit 1 button.

5. Set the value at coding address "D5" to "1". This setting initiates the external heating program changeover.

6. Set the value at coding address "D8" to "1". This setting identifies the changeover based on the DE1 contact.

7. Set the value at coding address "F2" to "0". This setting disables the time limit for the external heating program.

8. Set the value at coding address "F8" to "– 61". This setting disables the temperature limit for ending reduced mode.

9. Exit the Coding Level 2 menu. Open the main menu, tap the Heating button and then the Heating Circuit 1 button.

10. Set the normal day time Room Temperature Setpoint and Heating Curve to whatever values your customer requires.

11. Set the Reduced Room Temperature Setpoint to whatever value your customer requires (e.g. 3°C).

12. Clear all of the Heating Time Program schedules (Monday - Sunday).

13. Return to the main menu, and tap the DHW button.

14. Set the DHW Time Program schedules (Individual > Monday - Sunday) to "00:00 – 24:00".

15. Exit the main menu. The control is now configured to operate with a thermostat for Heating Circuit 1 via contact DE1.


Note:

When the contact at DE1 is closed, Heating Circuit 1 will operate in accordance with the outdoor sensor and the normal day time heating schedule.
When the contact at DE1 is open, Heating Circuit 1 will operate in accordance with the outdoor sensor and the reduced night time heating schedule.

3. Set the value at coding address "5E" to "1". This setting activates the DE2 contact.

4. Return to the Coding Level 2 menu, and then tap the Heating Circuit 2 button.

5. Set the value at coding address "D5" to "1". This setting initiates the external heating program changeover.

6. Set the value at coding address "D8" to "2". This setting identifies the changeover based on the DE2 contact.

7. Set the value at coding address "F2" to "0". This setting disables the time limit for the external heating program.

8. Set the value at coding address "F8" to "– 61". This setting disables the temperature limit for ending reduced mode.

9. Exit the Coding Level 2 menu. Open the main menu, tap the Heating button and then the Heating Circuit 2 button.

10. Set the normal day time Room Temperature Setpoint and Heating Curve to whatever values your customer requires.

11. Set the Reduced Room Temperature Setpoint to whatever value your customer requires (e.g. 3°C).

12. Clear all of the Heating Time Program schedules (Monday - Sunday).

13. Return to the main menu, and tap the DHW button.

14. Set the DHW Time Program schedules (Individual > Monday - Sunday) to "00:00 – 24:00".

15. Exit the main menu. The control is now configured to operate with a thermostat for Heating Circuit 2 via contact DE2.


Note:

When the contact at DE2 is closed, Heating Circuit 2 will operate in accordance with the outdoor sensor and the normal day time heating schedule.
When the contact at DE2 is open, Heating Circuit 2 will operate in accordance with the outdoor sensor and the reduced night time heating schedule.

3. Set the value at coding address "5F" to "1". This setting activates the DE3 contact.

4. Return to the Coding Level 2 menu, and then tap the Heating Circuit 3 button.

5. Set the value at coding address "D5" to "1". This setting initiates the external heating program changeover.

6. Set the value at coding address "D8" to "3". This setting identifies the changeover based on the DE3 contact.

7. Set the value at coding address "F2" to "0". This setting disables the time limit for the external heating program.

8. Set the value at coding address "F8" to "– 61". This setting disables the temperature limit for ending reduced mode.

9. Exit the Coding Level 2 menu. Open the main menu, tap the Heating button and then the Heating Circuit 3 button.

10. Set the normal day time Room Temperature Setpoint and Heating Curve to whatever values your customer requires.

11. Set the Reduced Room Temperature Setpoint to whatever value your customer requires (e.g. 3°C).

12. Clear all of the Heating Time Program schedules (Monday - Sunday).

13. Return to the main menu, and tap the DHW button.

14. Set the DHW Time Program schedules (Individual > Monday - Sunday) to "00:00 – 24:00".

15. Exit the main menu. The control is now configured to operate with a thermostat for Heating Circuit 3 via contact DE3.


Note:

When the contact at DE3 is closed, Heating Circuit 3 will operate in accordance with the outdoor sensor and the normal day time heating schedule.
When the contact at DE3 is open, Heating Circuit 3 will operate in accordance with the outdoor sensor and the reduced night time heating schedule.

Viessmann Technical Services 

Bulletin ID:     TSB-007

Date issued:   May 26, 2017

Updated on:   Jan 10, 2018

Revision #:      02

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