Viessmann Vitoconnect OT2 User Manual (English)

Questions and Answers:

S
stacey24Aug 9, 2025
What to do if my Viessmann Control Unit has no internet connection?
- V
  vswansonAug 9, 2025
  If your Viessmann Control Unit has no internet connection or cannot connect to the Viessmann server, check the network settings and password used during WiFi commissioning. If the WiFi signal strength is insufficient, consider changing the installation location of the Vitoconnect. If a WiFi connection is established but there's no internet, verify the internet connection with another device, such as a laptop. You can also try restarting the Vitoconnect.
A
Ashley LoveAug 16, 2025
How to fix Viessmann Control Unit when there is no connection to the boiler?
- P
  plongAug 16, 2025
  If your Viessmann Control Unit has no connection to the boiler, check the plug-in connections (Optolink, USB) and the connection lines (OpenTherm, Optolink). Restarting the Vitoconnect may also resolve the issue.
T
Traci BurnsAug 25, 2025
What to do if I can't connect my Viessmann Vitoconnect to WiFi?
- R
  Roy PriceAug 25, 2025
  If you cannot connect your Viessmann Vitoconnect to the WiFi router, first check the password used during WiFi commissioning. Also, ensure the connection to the WiFi router is stable. Restarting the Vitoconnect might help.
M
Ms. Kathleen Schultz MDSep 1, 2025
How to troubleshoot communication error with Vitotrol 100 on Viessmann Control Unit?
- M
  Michael RiveraSep 1, 2025
  If you are experiencing a communication error with the Vitotrol 100, type OT1, check the OpenTherm connecting cable to the Vitotrol 100. Restarting the Vitoconnect might also resolve the issue.

Viessmann Vitoconnect OT2 Specifications

General

Brand	Viessmann
Model	Vitoconnect OT2
Category	Control Unit
Language	English

Summary

Safety and Liability

Safety Instructions

General safety instructions to prevent accidents and material losses.

Installing and Settings

System Operation Safety

Safety measures for operating devices in dry, frost-free rooms and protecting them from environmental factors.

Auxiliary Components and Parts Safety

Operational Reliability

Ensuring system functionality, internet access, user registration, and power supply for reliable operation.

Liability

Limitations of liability for lost profit, damages from incorrect use, and contractual obligations.

Information Before Starting

Product Information

Operation using the ViCare App

How to control your heating system or individual room control remotely using the ViCare app.

Preparing for Installation

System Requirements

Details on supported control units, IP network requirements, and Viessmann account for Vitoconnect operation.

Installation Site - Vitoconnect

Guidelines for the Vitoconnect installation site, including wall mounting, environment, and power socket requirements.

Installation Sequence

Overview of Steps for Installation and Commissioning

Installing Wall Bracket for Vitoconnect

Inserting the Cables

Connecting Vitoconnect OPTO2 to Heat Generator

Steps for connecting the Vitoconnect OPTO2 to the heat generator using the Optolink/USB connecting cable.

Connecting Vitoconnect OT2 to Heat Generator

Instructions for connecting Vitoconnect OT2 to the heat generator using the OpenTherm connecting cable.

Connecting Vitoconnect OT2 to Vitotrol 100

Closing Vitoconnect and Inserting into Wall Bracket

Closing Vitotrol 100 and Inserting into Wall Bracket

Vitoconnect Mains Connection

Commissioning

Display and Operating Elements

Meaning of the LEDs

Detailed explanation of the LED indicators for operating status, communication, and system functions.

Checking Network Settings

Registering Users and Setting Up Heating System

Steps for downloading the ViCare app, creating an account, and setting up the heating system.

Establishing EEBUS Connection

Commissioning with Energy Management System

Steps for commissioning Vitoconnect with Viessmann energy management systems like GridBox.

Requirements for Viessmann GridBox Commissioning

Commissioning with Viessmann Energy Management System

Steps for commissioning Vitoconnect with Viessmann energy management systems, including security key comparison.

Commissioning Steps

Detailed steps for commissioning Vitoconnect with energy management systems, including browser access and device discovery.

Energy Management Integration for Heat Pumps

Setting heat pump parameters for Smart Grid function via EEBUS and managing set value boosts.

Operating Functions

Adjusting Room Temperature Temporarily

Setting Comfort Mode

Ending Comfort Mode

Enabling Access Point Mode

Disabling Access Point Mode

What to Do? - Troubleshooting

Measures for Troubleshooting - Internet Connection Interrupted

Steps to take when the internet connection is interrupted, affecting ViCare app settings.

Fault Display on the Vitoconnect

Faults with LED ((0))

Description of faults indicated by the ((0)) LED and corresponding measures for resolution.

Faults with Other LEDs

Description of faults indicated by other LEDs and corresponding measures for resolution.

Troubleshooting - No LED Indicator

Restarting the Vitoconnect

Instructions for restarting the Vitoconnect by pressing the reset and operating buttons simultaneously.

Resetting to Factory Settings

Procedure for resetting the Vitoconnect to its factory settings by pressing the reset button.

Setting Up Wi-Fi After Replacing Router

Maintenance

Software Update

Specification

Vitoconnect, Type OPTO2 and OT2 Specifications

Technical specifications for Vitoconnect OPTO2 and OT2, including voltage, Wi-Fi, frequency, and IP rating.

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