Vaillant VRT-350F user manual

The recommended temperature setting for a Vaillant boiler is between 60°C and 65°C. However, the ideal temperature may depend on your specific model and your hot water needs. Always check your user's manual or consult with a professional for personalized advice.

There could be several reasons why your Vaillant VRT-350F thermostat is not working. Here are a few possible causes and solutions:
1. Power Issues: Check if the thermostat has power by ensuring it is properly connected to the power source or batteries. Replace the batteries if needed.
2. Incorrect Settings: Ensure that the thermostat is set to the desired mode (heating/cooling) and temperature. Check if the timer settings are correct.
3. Faulty Wiring: Examine the wiring connections between the thermostat and the heating/cooling system. Make sure all wires are securely connected and not damaged. If necessary, call a professional to check and fix any wiring issues.
4. Device Placement: Check if the thermostat is placed in a suitable location, away from heat sources, direct sunlight, or drafts. Incorrect placement can affect temperature readings.
5. Sensor Issues: The thermostat's temperature sensor may be faulty or dirty. Clean the sensor carefully with a soft brush or cloth. If the sensor is damaged, it may need to be replaced.
6. Technical Problems: If none of the above solutions work, there might be a technical issue with the thermostat itself. In this case, it is advisable to contact Vaillant customer support or a professional technician to diagnose and fix the problem.

The Vaillant VRT-350f thermostat has several modes:
1. Comfort Mode: This mode ensures optimum heating comfort by maintaining a specific temperature setpoint.
2. Eco Mode: This mode allows energy-saving, as it lowers the temperature setpoint to reduce energy consumption.
3. Manual Mode: In this mode, users can manually adjust the temperature setpoint according to their preferences.
4. Party Mode: This mode temporarily increases the temperature setpoint for a specific duration to provide additional comfort during social gatherings or parties.
5. Holiday Mode: By activating this mode, users can set a lower temperature setpoint during their absence to save energy.
6. Off Mode: This mode turns off the thermostat and heating system completely.
7. Frost Protection Mode: This mode activates when the temperature drops significantly to prevent freezing and protect the pipes from damage.
It's important to note that the availability of these modes may vary depending on the specific model and firmware version of the Vaillant VRT-350f thermostat.