Money-Saving Tips to Reduce Your Heating Bills

The Most Impactful Changes Start with Your Heating System

For most London homeowners, heating accounts for the largest portion of domestic energy consumption. And while the obvious advice — turn the thermostat down, wear a jumper — isn't wrong, the most impactful changes are usually made not to behaviour but to how the heating system itself is configured and operated.

Here are the practical measures that make the biggest difference, starting with the ones that cost nothing at all.

1. Lower Your Boiler Flow Temperature

This is the single most impactful free change available to most homeowners with a modern condensing boiler. The flow temperature is the temperature at which hot water leaves the boiler to circulate through the heating system. Most boilers are set to 70–75°C by default — far higher than necessary for most properties.

Modern condensing boilers achieve their headline efficiency figures only when operating in condensing mode, which requires return water temperatures below 55°C. By lowering the flow temperature to 55–60°C (for radiator systems) or 35–45°C (for underfloor heating), the boiler operates in condensing mode far more of the time. Studies consistently show gas savings of 6–12% from this single change. Access the boiler's menu settings — consult your manual or call us if you're unsure.

2. Install Weather Compensation Controls

Weather compensation adjusts the boiler's flow temperature automatically based on outdoor temperature. On mild days, the boiler runs at lower output. On cold days, it runs higher. The result is a system that never uses more energy than the building actually needs at any given moment. This can reduce gas consumption by 10–20% compared to a standard on/off thermostat-controlled system. Many premium boilers have this capability built in but disabled — it requires only an outdoor sensor to activate.

3. Install a Magnetic System Filter

Magnetite sludge in your heating system forces the boiler to work harder, reduces radiator and UFH efficiency, and accelerates component wear. A quality magnetic filter (Fernox TF1, Spirotech, Adey MagnaClean) captures this sludge before it reaches the boiler. If your system doesn't have one, installing one is one of the best value-for-money investments in your heating system's performance.

4. Upgrade to Multi-Zone Smart Controls

A single-zone thermostat heats every room in the property to the same temperature. In a large London home, this is inherently wasteful. Installing zone controls — Heatmiser NeoHub, Tado, Honeywell evohome — allows you to heat only the rooms in use, at the temperatures you want, on the schedules that match how you actually live. Energy savings of 15–25% are realistic in larger properties making this upgrade.

5. Have Your System Hydraulically Balanced

An unbalanced heating system means some radiators and UFH loops are getting too much flow while others are starved. The result: some rooms overheat while you compensate with higher boiler temperatures than necessary. A proper hydraulic balance — adjusting flow rates to each circuit to match the room's actual heat requirement — allows the boiler to run at lower flow temperatures while delivering correct comfort everywhere.

6. Insulate Your Property Properly

No heating system improvement compensates for poor insulation. In London's period property stock, the biggest single source of heat loss is often draughts: gaps around skirting boards, uninsulated loft hatches, chimney breasts without dampers, poorly fitting sash windows. Many of these can be addressed cost-effectively without major works. Loft insulation, where absent, offers some of the best returns on investment of any energy efficiency measure.

7. Service Your Boiler Annually

A boiler that hasn't been serviced is an inefficient boiler. Scale buildup on heat exchangers, degraded seals, out-of-calibration combustion — all reduce efficiency and increase gas consumption. An annual service maintains peak combustion efficiency, extends component life, and catches developing faults before they cause expensive failures.

8. Don't Heat What You're Not Using

Programmable thermostats that match the heating schedule to how the property is actually occupied make an immediate difference. If the property is empty between 9am and 5pm, the heating shouldn't be running at full comfort temperature during those hours. This is basic but frequently overlooked — particularly in properties where the heating schedule has never been updated since installation.

9. Check Radiator and UFH Valve Function

Thermostatic radiator valves (TRVs) and UFH actuators that are stuck open heat rooms regardless of demand. Stuck closed, they leave rooms cold and force you to raise the overall system temperature. A quick check of valve function across your property — part of any decent service visit — ensures the system is responding correctly to demand.

10. Consider a System Efficiency Audit

If your energy bills feel disproportionately high relative to your property size and usage, a professional system efficiency audit — reviewing combustion performance, flow temperatures, water quality, balancing, and controls — can identify the specific interventions that will have the most impact. At RARE Plumbing London, we carry out efficiency assessments for prime London properties and can prioritise recommendations by cost-effectiveness.