Cap hot water at 55 degrees Celsius

Many boilers are set to 65–75 °C, much higher than needed. If you lower the temperature to 60 °C, you save about 5–10% heating energy per 5 degrees. Extra benefit: lower burn risk for children.

Step by step

A boiler (storage heater) heats water to your set temperature and keeps it constant. Heat losses from the storage tank are proportional to the temperature difference between water inside and outside air. At 75 °C the difference is bigger than at 60 °C, more heat radiation outward, more condensation loss in pipes. Plus: the hotter the water, the more energy needed to heat it. 60 °C is completely sufficient for Legionella prevention (they die above 60 °C).

Step by step

1. Identify your boiler typeLook in your basement or heating room: do you have a large storage tank (metallic, cylindrical, 100–300 L)? That's a boiler. On top or the side sits a thermostat control with degree scale or digital display.
2. Read the current temperatureLook at the setting on the control: is a pointer set to a degree marking? Read the current number (often 65–75 °C). Write it down.
3. Lower temperature to 60 °CTurn the screw/slider on the thermostat so the target marker shows 60 °C. Some controls have a slotted screw, others a turn knob. Adjust slowly, not quickly.
4. Wait 30 minutes and checkAfter 30 minutes: open a warm tap (bathroom, kitchen) and test the temperature by hand or thermometer. Should be pleasantly warm (~50–55 °C coming out, as pipes lose some heat).
5. Long-term monitoringAfter 1 week: check your heating cost meter or gas use. A reduction of 5–10% is normal. If temperature feels too cold, increase to 62–63 °C.

Worked example

How much do YOU save with lower hot water temp?