Low hot water temperature or lack of hot water — Inefficient hot water production

What does Low hot water temp mean?

The system is not producing enough hot water, or the water temperature is lower than expected. This can be due to various settings, external valves, or high consumption.

• Externally mounted hot water filling valve is closed or throttled.
• Mixing valve (if installed) is set too low.
• VVM S320 is in an incorrect operating mode.
• High hot water consumption.
• Hot water setting is too low.
• Low hot water access due to active "Smart Control" function.
• Supply temperature for hot water set too low.

Click steps to track your progress.

1. 1

   Check if any externally mounted filling valve for the hot water is closed or throttled, and open it fully.

2. 2

   If a mixing valve is installed, adjust it to a higher setting.

3. 3

   Verify the VVM S320's operating mode in menu 4.1 - "Operating mode." If "Auto" is selected, increase the "Stop additional heat" value in menu 7.1.10.2. If in "Manual" mode, ensure "Additional heat" is activated if there's no air/water Heat Pump.

4. 4

   If there's been large hot water consumption, wait for the water to heat up. Temporarily activate "More hot water" via the "Hot water" home screen, menu 2.1, or myUplink.

5. 5

   Enter menu 2.2 - "Hot water demand" and select a higher demand mode.

6. 6

   If "Smart Control" is active and usage has been low, activate "More hot water" via the "Hot water" home screen, menu 2.1, or myUplink to override the low production.