Why does your energy bill explode in winter in Brussels?
In Belgium, heating accounts for an average of 60 to 70% of a household's annual energy bill. In Brussels, with harsh winters and an often older housing stock, heat losses can be considerable. The good news: with a few simple adjustments, you can reduce your consumption by 15 to 30% without sacrificing comfort.
1. Set your thermostat to the right temperature
This is the simplest and most effective tip. Each extra degree represents about 7% more consumption.
- Living spaces: 19-20°C during the day
- Bedrooms: 16-17°C at night
- Unoccupied rooms: 14-15°C (just to prevent freezing)
- When you leave the home for more than 2 hours: lower to 15-16°C
A programmable or smart thermostat (Nest, Tado, Netatmo) does all this automatically and pays for itself in 1 to 2 seasons.
2. Service your boiler before winter
A dirty boiler consumes up to 15% more energy. In Belgium, annual maintenance is mandatory for gas boilers. Schedule it in September or October, before technicians are overloaded in December.
A complete service includes: burner cleaning, safety checks, performance adjustment, CO₂ emissions measurement. MLAN Services performs these services in Brussels with issuance of the required PEB certificate.
3. Bleed your radiators
If some radiators have a cold zone at the top, there is air in the circuit. Bleeding takes 5 minutes with a radiator key (less than €3):
- Turn off heating and wait for radiators to cool
- Place a cloth under the bleed valve (at the top of the radiator)
- Open the valve slightly until you hear air escaping
- Close as soon as water flows without bubbles
- Recheck circuit pressure (should be between 1.5 and 2 bar)
4. Balance your heating circuit
If some rooms are too hot and others too cold, the hydraulic circuit is poorly balanced. Thermostatic valves on each radiator allow fine-tuning the temperature room by room. A technician can balance the entire circuit to optimize overall efficiency.
5. Free thermal bridge insulation
Without investing in full insulation, you can act on:
- Window seals: silicone or foam seal costs a few euros and eliminates draughts
- Door draught excluders: a draught excluder blocks cold air from corridors or cellars
- Shutters and thick curtains: closed at night, they reduce heat loss through windows by 10 to 15%
- Radiators behind furniture: move sofas or bookcases that block the heat
6. Only heat occupied spaces
Close the doors of unused rooms and lower their radiators to minimum. However, a cold room not insulated from the rest of the house creates a thermal bridge — never go below 14°C to avoid condensation and mould.
7. Optimise ventilation
Ventilating is essential for air quality and to prevent humidity (enemy of insulation), but poorly adjusted ventilation can waste a lot of heat.
- Ventilate 10 minutes per day, windows fully open: more efficient and less energy-wasting than leaving a window ajar for hours
- If you have an MVHR, have filters cleaned annually
- Never block ventilation grilles
8. Reduce domestic hot water temperature
Domestic hot water accounts for 15 to 20% of the energy bill. The hot water tank is often set too high:
- Recommended temperature: 55-60°C (kill legionella while saving energy)
- Above 60°C: pure waste
- Below 55°C: legionella risk
A thermodynamic boiler can reduce this by 70% — MLAN Services can advise you on models and calculate available grants in Brussels.
9. Use free solar gains
In winter, the low sun provides free heat:
- Open blinds and curtains on the south and west sides during sunny hours
- Close them as soon as the sun disappears
- Don't obstruct south-facing windows with large plants
10. Consider renewable energy for the future
For lasting savings, an air/water heat pump can reduce your heating bill by 50 to 70% compared to a gas boiler. In 2026, significant grants are available in the Brussels-Capital Region. MLAN Services carries out the audit and complete installation.
Summary: how much can you save?
| Action | Estimated saving | Cost |
|---|---|---|
| Thermostat -1°C | ~7% | Free |
| Boiler service | up to 15% | €150-300/year |
| Bleed radiators | 2-5% | Free |
| Window seals | 3-8% | €10-30 |
| Programmable thermostat | 10-15% | €50-200 |
| Heat pump | 50-70% | €8,000-15,000 (with grants) |
Need a boiler service or energy-saving advice in Brussels? MLAN Services operates in all Brussels communes. Call 0491 12 02 33 — free quote, free callout.