June 17, 2025, 4:40 am | Read time: 2 minutes
When the temperatures outside become summery warm again, it’s obviously not very sensible to keep the heating running. That’s why there’s a setting for summer operation. However, this too has its weaknesses, as an expert explains.
With heating systems, there’s an option to switch to summer mode. This is typically done when it’s warm enough and heating is no longer necessary. In summer mode, the heating system only produces hot water, not heating warmth. While this initially sounds sensible, it also has its drawbacks and can even have negative effects.
Caution with Self-Regulating Systems
The energy-saving tip of using summer mode isn’t always advisable. This is particularly true for self-regulating systems, explains the German Association for Liquefied Gas. These systems can still activate in summer mode if it gets too cold, such as during cooler nights or a sudden temperature drop during a summer storm.
Unnoticed Energy Waste
What many don’t know: Numerous heating systems have outdoor temperature sensors that detect weather changes and adjust the heating accordingly. Residents often don’t notice this, resulting in unnecessary energy consumption.
Therefore, the association advises that for systems with smart controls that automatically switch to summer mode, users should manually adjust the settings. During the warm months, the heating should only produce hot water for the kitchen and bathroom. The Consumer Advice Center also recommends completely shutting off the heating system in summer or switching to a hot water-only mode.
When Should You Turn Off the Heating?
This generally depends on the weather conditions. By May, it’s usually warm enough to turn off the heating or switch to hot water mode. By June 1, the official start of summer, heating is no longer necessary. The heating period then begins again on October 1.
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It sounds paradoxical, but it’s recommended: Turn the thermostats on the radiators fully up when using them only for hot water. This might seem odd with warm outdoor temperatures, but it relaxes the mechanism that regulates water flow into the radiators. “This helps prevent the valves from sticking in the summer and getting stuck at the start of the next heating period–which could require replacement,” explains DVFG technical expert Markus Lau.
With material from dpa