The nationwide cold snap is forcing many households in Spain, to turn up their heating – and pushing up energy bills immediately. The share of household budgets taken up by heating is quantified by the Instituto para la Diversificación y el Ahorro de la Energía (IDAE): during the coldest months, space heating accounts for between 47 and 60 per cent of household energy consumption. This range comes from the IDAE analysis of household energy consumption, published on 11 September 2025.
This makes avoidable operating mistakes costly very quickly. The consumer protection organisation OCU has long listed common causes of excess consumption: setting target temperatures too high, heating unused rooms continuously, incorrectly set or missing thermostats and poor system maintenance. Even simple maintenance oversights, such as failing to bleed radiators reduce heat output and drive up fuel consumption.
In the short term, three adjustments are particularly helpful. First, choose a moderate target temperature; even one degree less noticeably reduces consumption. Second, use timers and thermostats consistently – for example, to lower the temperature automatically at night or when away, and heat only occupied areas. Third, keep the system in good condition: bleed radiators, check pump operating times, and have filters and burners serviced. These measures usually require little investment but deliver measurable savings.
In the medium term, it is advisable to improve the building envelope and upgrade the controls. Well-sealed windows, sealed roller-shutter boxes and correctly set heating curves permanently reduce demand. When replacements are due, it is worth comparing system efficiency: for many homes, electrically powered heat pumps can reduce costs, depending on insulation and tariffs; where this is not suitable, variable-speed circulation pumps and programmable thermostats can at least help. Which option is cost-effective depends on the building, climate and tariffs.
The IDAE figures provide a reliable basis for understanding the share of household costs involved, while the OCU guidance points to practical ways to manage consumption. Forecasts of future bills remain uncertain, however, as they depend on international energy prices and national tariffs. One thing is clear: as the heating season begins, the right settings matter more than ever to the size of the bill – and many costly mistakes can be corrected quickly.
Editor: Daniel Mayer (Article created with AI assistance).