How can we help?

Having trouble? Click here to access our troubleshooting guide.

Your Question:




The Vaillant vSMART is a Internet enabled Roomstat control that is currently in production. Please check the frequently answered questions below for any help you may need. You can also click here to visit the appliance homepage.  


Frequently Asked Questions


General Information

What are smart heating controls?

Smart heating controls can mean a lot of different things. For example, load compensation is a smart control, especially if it 'learns' how long it takes your house to heat rather than asking you to select a temperature curve. Smart controls can also: • Turn the radiators off when the front door is open or windows are open • Turn the radiators down 1 or 2 degrees when there is no-one in a room • Prioritise flow through radiators where there is heat demand and adjust the radiator flow temperature when necessary • Give you remote control through your smart phone There is a European standard for smart controls (EN 15232) which describes the services which can be provided and estimates the savings achievable in different situations. For a residential property with full automation the savings ( over the reference case which is for a home with a condensing boiler, programmable thermostat with weather compensation and TRVs) are around 20%.

How does it work?

The Gateway is connected to the boiler via an eBUS cable and controls the heating. The Gateway communicates wirelessly with your thermostat where the room temperature can be viewed and the room temperature can be increased. The Gateway unit establishes a WLAN connection to the internet through your wireless enabled internet router. The information is encrypted and securely sent to our servers which then communicates to the app on your device. See picture below:

When was the roomstat manufactured?

This roomstat was first manufactured in 2016 and is still in production.

is it wired or wireless

The vSMART is a wireless device. It connects wireless to its roomstat and connects via wlan wireless to your internet router.

What kind of Appliance is it?

This appliance is an internet-enabled roomstat control. This means it also comes with a Smartphone app for Android and Apple. It is self-learning and it has built in weather compensation.

What is considered the best temperature?

Studies recommend a temperature of 19 °C during the day and 16 °C at night. Consider decreasing the temperature and saving energy without having to compromise on your comfort. Decreasing the temperature by just 1 °C consumes 7% less energy

How can I save energy in general?

It is easy to save energy when heating: Install a room thermostat (which measures the temperature in your living room and sets the boiler accordingly) and set a comfortable and appropriate target value for the temperature. Create a heating programme which takes your daily activities into account. By controlling your heating remotely, you can avoid heating it when you are not at home. When using a heating programme that follows your daily activities, the thermostat decreases the temperature overnight and while you are away from home. If you are using the app for the first time, a weekly heating programme will be created on the basis of your activities. You can access and change the programme at a later date using the app (by tapping on the clock symbol). If you are away from home for long periods, you can reduce your energy consumption by activating the "Days away from home" or "Frost protection" mode. You can save energy in both instances: Although it costs energy afterwards to bring the house back up to the set target temperature, you can avoid temperature losses (proportionally to the temperature drop between inside and outside) by decreasing the temperature at home. In short: It is always more beneficial to heat your home up again than it is to maintain a constantly high temperature while you are away.



Can I get a description of the controls?

What do the operating mode selection buttons do?

Tapping on the bottom "(System mode)" button opens a selection menu where you can switch between "Winter" mode (heating and hot water active), "Summer" mode (only hot water active) and "Off/Frost protection" mode. Activate the "Frost protection" mode for longer periods away from home. It sets the boiler to minimum operation to make sure that the water does not freeze. You can change the preset value of 7 °C in the heating programme. The "Frost protection" mode is active until you override it manually.

Setting up for the first time

If you are starting the app for the first time, you can create your personal programme by answering a few questions. It makes sure that the temperature is always suitable for your activities, offering a very high level of comfort. Setting a lower temperature at night and while away from home helps the programme save energy. You can access the heating programme by tapping on the clock symbol on the top right of the app. You can change existing values by tapping on the heating periods. To reset the heating programme, first clear the existing data under Options -> Your thermostat -> Reset weekly programme.

How do I set the temperature on the thermostat?

The thermostat displays the set target temperature and the measured room temperature. If you do not set the temperature manually on the thermostat, it follows the temperatures specified in your weekly heating programme. If you want to set a different temperature, press the "+" button on the thermostat to increase the set target temperature, and the "-" button to decrease it. The thermostat will then stop following the weekly programme for a certain period of time. This period of time can be specified in the "Advanced Settings" menu on the app. Once it has elapsed, the thermostat follows the weekly heating programme again.

How do I set the temperature/use override?

The target value set (by you) for the room temperature and the current temperature measured by the thermostat, as well as the local outside temperature retrieved online, are all displayed centrally on the app. To increase or decrease the set target temperature using the app, tap on the "+" or "-" button next to the target value shown. This changes the target value temporarily. You can then set the duration using the timer which is now shown (from 1 to 12 hours). Once this time has elapsed, the target value will return to being determined by the programme once more.

How does the heating and Hot water program work?

The weekly programme is divided into heating periods. Each heating period has a start and end time point and a profile assigned to it. The profile consists of a temperature, an assigned name, a colour and an on/off switch for hot water generation. After selecting the clock symbol on the top right, select a day (1) and then modify profiles (2).  There are three preset profiles: "At home", "night" and "away". You can add additional profiles (for example "", "Sport", or similar). Depending on the situation, you can specify for the selected temperature whether you also need hot water during this period or not. This means you only have to set the hot water temperature in one place. Please view the video below for further help in setting vSMART time programs. You can see a full range of helpful self-help videos by accessing our Vaillant Youtube Channel here.

What does Room compensation mean?

This means the controls look first at the user set room temperature, then the controls look at the actual room temperature. The controls will then increase or decrease the boiler flow temperature in the most efficient way possible to reach the desired set point. As the set point is being reached the flow temperature to the radiators will reduce as the boiler modulates down to match the heat loss of the property while still maintaining the set point.

Does the vSMART have Weather compensation?

The vSMART has weather compensation as well as Enhanced Load compensation. Weather Compensation monitors the outside temperature and the eBus controls adjust the flow temperature based on a pre-selected heat curve and the room set point. Weather compensation just adds another dimension to temperature control but on its own is not Enhanced Load Compensation .

What is frost protection mode?

This is a minimum temperature which always applies, regardless of the other settings. This should be just enough to keep your pipes from freezing - around 5-7 C



Can I control multiple roomstats?

Yes, you can connect multiple vSMART's to your vSMART smartphone app. This is handy if you have would like to control the heating in multiple properties.

What happens if the Internet connection is interrupted?

If the Internet connection is lost, the thermostat will start operating as a normal thermostat. It follows the heating programme, taking the measured temperatures into account, and also switches to "away" and "Frost protection" mode until you manually override it with a different setting. Please view the video below for further help in resolving vSMART connection problems. You can see a full range of helpful self-help videos by accessing our Vaillant Youtube Channel here.

What should I do if the battery or wireless problem symbol is displayed on the thermostat?

If your thermostat is showing the battery symbol, this means that the batteries are flat and need to be replaced. If the thermostat and the Gateway are too far apart, or if they are separated by thick walls, communication may not always be possible. If this is the case, the thermostat will display the "No RF signal" symbol. To re-establish the connection, reduce the distance between the thermostat and the communication unit. It may take up to a minute to search for a signal and establish an RF connection.

How do I check if there is power to the vSMART?

To check the power supply for the communication unit, remove the mains plug for a few seconds. Once the power supply has been re-established, the status LED should flash blue on the communication unit. If this is not the case, the power supply is faulty.

How do I set the weekly and daily heating programmes?

The programme splits the day up into heating periods. Each of these heating periods is assigned a temperature and a name. Select the programme function by selecting the clock symbol on the top right of the App.

How do I Change or delete the temperatures

If you change the temperature, the change takes effect in all profiles that use it. For example, if you have a heating period "Night – 16 °C", which goes from 23:00 to 6:00, and you change the night temperature to "Night – 15 °C", the heating is regulated at 15 °C every night between 23:00 and 6:00. You can delete a temperature provided that it is not used by any heating period. To change or delete temperatures, click on "Change temperatures" in the programme. The following colour scale shows you at a glance which temperature is assigned to which heating period.

What are the "Away“ and "Hot Water Boost“ icons?

The "Away" and "Hot Water Boost" modes can be set as shortcut buttons on the app. Use the "Away" mode if you are travelling for just a couple of days. This mode decreases the temperature and reduces your heating bill as a result. You can change the preset value of 12 °C in the heating programme. Tap on the "Away" button and set the time of your intended return in the menu that opens. Confirm your entry with "OK". Use the "(hot water boost)" button to activate the one-off, unscheduled provision of hot water, should you need it outside of the times set in the "Process water temperature/Hot water temperature" menu.

Is the vSMART Open-Therm compliant?

The vSMART as well as the other Vaillant controls do not use the Open-therm protocol

What is PID?

vSMART uses enhanced load compensation, weather compensation, and self-learning. It also uses PID (Proportional, Integral and Derivative) algorythm continuously modulating control system, to give the most efficient control system available. More information is available in the Engineer Support section.

I am an Engineer. I would like technical information. Where can I get help?

If you are a suitably qualified Gas Safe registered Engineer you can access our comprehensive technical help section by clicking here.


Available Literature


Installation Manual Brochure User Guide

Were we able to answer your question(s)?