Is Your Heating Fighting Against Your House? Five Mistakes That Waste Money

Your heating system may be working perfectly—and still wasting your money.

The boiler fires up. The heat pump hums away. The radiators become warm. Yet you are sitting on the sofa wondering whether to turn the thermostat up another degree.

Before you do, it is worth asking a different question:

Is the heat reaching the places where you actually need it?

Heating a home involves more than producing hot water and circulating it around some radiators. Furniture, curtains, thermostat position, control settings and daily routines all influence the result.

Sometimes the problem is surprisingly ordinary: a sofa blocking a radiator, a thermostat measuring a draughty hallway, or a heating programme that still follows a timetable nobody uses.

In our own home, with an air source heat pump, solar panels and battery storage, heating is part of a wider energy system. That makes me particularly interested in how the different parts work together. Buying efficient equipment is one step; understanding how the house responds is another.

The same principle applies whether you have a gas boiler, an oil boiler or a heat pump.

Before increasing the thermostat, spend 15 minutes investigating what your heating is already doing.

Mistake 1: Heating the Back of the Sofa Before Heating the Room

A radiator behind a large sofa may be conveniently hidden, but that arrangement can make it harder for warmth to spread into the room.

Despite their name, radiators transfer much of their heat by convection: air warms around them, rises and circulates. They also emit radiant heat towards surrounding surfaces.

Push bulky furniture against the radiator and you interfere with that circulation while shielding the room from some of its radiant warmth.

The energy absorbed by the furniture does not simply disappear. Much of it eventually reaches the room. The problem is that heat may be distributed poorly, leaving the occupied part of the room uncomfortable and encouraging you to increase the heating.

Look for these common obstructions

• A sofa pressed against a radiator.

• A bed or chest of drawers covering most of its front.

• Long curtains hanging over it.

• A decorative radiator cover that restricts airflow.

• A thermostatic radiator valve trapped behind furniture or curtains.

That last point matters because a thermostatic radiator valve, or TRV, senses the temperature around its own valve head. A warm pocket of air behind a curtain can cause it to reduce the radiator’s output while the rest of the room remains cooler.

A practical improvement

Where possible, rearrange furniture to leave the radiator unobstructed. If that is impractical, increase the clearance and give warm air a clear route into the room, following any manufacturer’s guidance.

Close curtains at night, but keep them clear of the radiator.

Then assess comfort before changing the thermostat. Guidance from MoneySavingExpert also recommends keeping bulky furniture away from radiators so heat can circulate more freely.

The question is not simply whether the radiator gets hot. It is whether its warmth reaches you.

Mistake 2: Letting the Thermostat Measure the Wrong Place

Your thermostat makes decisions using the temperature at its sensor.

That may be very different from the temperature beside your favourite chair.

A thermostat near a sunny window, a radiator, a television or another heat source may decide the house is warm enough before the main living area becomes comfortable.

A thermostat exposed to a draught or close to an outside door can have the opposite effect: it keeps calling for heat while other rooms become unnecessarily warm.

Energy Saving Trust advises that room thermostats need freely circulating air and should be clear of furniture, curtains and nearby heat sources.

Imagine this situation

Your thermostat is set to 20°C.

The hallway feels chilly whenever someone opens the front door, but the sitting room has reached 23°C.

Turning up the thermostat because the hallway feels cold could make the sitting room warmer still. The underlying issue may be thermostat location, draughts, radiator balance or how the controls interact.

What should you check?

Ask:

• Is the sensor exposed to direct sunlight?

• Is there a draught nearby?

• Has furniture been placed around it?

• Is it close to equipment that produces heat?

• Does its reading reflect the rooms where people spend their time?

With a wireless thermostat, check the instructions before trying a more representative position. A fixed thermostat may need an installer’s advice.

Also check how the main thermostat and radiator valves are intended to work together. If a TRV shuts the radiator in the thermostat’s room before the thermostat reaches its target, some systems can continue requesting heat unnecessarily.

A thermostat can be accurate and still be measuring an unhelpful location.

Mistake 3: Running the Heating Water Hotter Than Necessary

There are two temperatures that are easily confused:

Room temperature is how warm you want the room to be.

Flow temperature is the temperature of the water sent through your radiators or underfloor heating.

Increasing one is not the same as increasing the other.

If you have a condensing combi boiler

A lower heating flow temperature can improve efficiency, provided the radiators can still keep the home comfortably warm.

For a suitable condensing combi boiler, around 60°C can be a useful starting point for investigation. Some homes can use lower settings in mild weather; others need higher temperatures during cold spells.

Lower flow temperatures reduce radiator output, so the house may take longer to warm. The aim is to find a setting that meets the heating demand efficiently—not to achieve the lowest number on the display.

Check the manual and identify the central-heating control, rather than changing the domestic hot-water setting. Energy Saving Trust recommends adjusting controls first and checking that comfort is maintained when lowering flow temperature.

If your boiler heats a hot-water cylinder

Do not automatically copy advice intended for combi boilers.

Where the same boiler temperature setting serves both radiators and a cylinder, it must remain high enough to heat stored water safely. Some installations have separate arrangements that allow different temperatures.

Check your system’s instructions or ask your heating engineer before changing it. Energy Saving Trust advises a boiler flow temperature of at least 65°C for conventional arrangements that need to heat a cylinder to 60°C.

If you have a heat pump

Heat pumps generally benefit from delivering heat at lower water temperatures over longer periods.

A radiator that feels gently warm may be doing exactly what it should. Its surface does not need to feel like an old boiler-fed radiator for the room to be comfortable.

Weather compensation adjusts heating water temperature according to outdoor conditions. If your system has it, understanding the heating curve can be more useful than repeatedly overriding the controls. Make gradual changes within the manufacturer’s guidance, with installer support where needed.

Judge the heating by the comfort it provides and the energy it uses, rather than how fiercely hot the radiators feel.

Mistake 4: Heating to Yesterday’s Timetable

Heating programmes are often set once and forgotten.

Meanwhile, life changes.

Someone starts working from home. A regular evening activity moves. Children leave home. A room becomes an office. The household starts getting up later.

The heating continues following the old routine.

For a boiler system

Review when warmth is needed and how long your house takes to warm up.

You may find that heating starts too early, continues well after bedtime, or maintains daytime temperatures while the house is empty.

Equally, starting too late can encourage repeated use of the boost button.

Check the programmer’s clock as well. With the autumn clock change approaching, it is a useful detail to include in your heating check.

For a heat pump

Avoid assuming that the best boiler schedule is also the best heat-pump schedule.

Longer operating periods and modest temperature setbacks often suit heat pumps better than short heating bursts and deep overnight temperature reductions. The right arrangement depends on the building, system and electricity tariff.

In our home, solar generation and battery storage add another consideration: when electricity is available and what it costs. But tariff timing still has to work with the heating system and the comfort we need.

Try a three-day diary

Record:

• When the house becomes comfortable.

• When anyone feels cold.

• When rooms become too warm.

• When somebody overrides the programme.

• Whether those changes were actually needed.

Repeated overrides often reveal a schedule that no longer fits.

Your heating programme should reflect the people living in the house now.

Mistake 5: Overheating the House to Solve One Cold Spot

One chilly chair can persuade us to increase the temperature of an entire heating zone.

Yet the discomfort might come from a nearby draught, cold glazing, an external wall or poor heat distribution.

Raising the thermostat can make every other part of the zone warmer without dealing with the cause.

Temperature is only part of comfort

Two rooms can have the same air temperature and feel different.

Cold surfaces affect how quickly your body loses radiant heat. Moving air can make you feel colder. Sitting still usually requires more warmth than moving around.

That is why a thermometer helps, but does not explain everything.

Find a comfortable setting deliberately

If your home regularly becomes warmer than you need, try a small reduction and allow time to judge it.

For many people, room thermostat settings fall between 18°C and 21°C, but individual needs differ. Some people need warmer conditions because of their age, health or limited mobility. Reducing waste should preserve adequate warmth.

With a simple on/off thermostat, turning it far above the temperature you want generally makes the heating run longer rather than warming the room faster. More advanced controls can behave differently, so understand your system.

Nor should saving money mean leaving rooms cold for long periods. Very cold rooms can develop condensation, damp and mould; heating, moisture control and ventilation need to work together.

Find out why one place feels cold before asking the whole house to become hotter.

The Two-Thermometer Experiment: Where Does the Warmth Reach?

This is a small investigation you can do with two ordinary room thermometers.

It will not measure heat flow directly or calculate your heating efficiency. It can reveal temperature differences worth investigating.

Step 1: Check the thermometers together

Place both instruments side by side, away from sunlight and heat sources.

Allow them to settle according to their instructions and note any difference. If one consistently reads 0.4°C higher, remember that when comparing locations.

Step 2: Compare two useful positions

Place thermometer A near the main thermostat, without touching it or the wall.

Place thermometer B near where you normally sit, around seated upper-body height.

Keep both away from direct sunlight, hot radiator plumes and contact with warm or cold surfaces. You want comparable air-temperature readings.

Step 3: Let the heating operate normally

Leave the thermostat at its usual setting.

Record both readings once they have settled, then again during the heating period. Some thermometers respond slowly, so allow longer than 15 minutes if necessary.

Step 4: Swap them

Exchange the instruments between the two positions and allow them to settle again.

If the difference follows the location, rather than the thermometer, that strengthens the evidence that the two places have different temperatures.

Step 5: Change one thing

For example:

• Clear furniture from the radiator.

• Lift a curtain away from a radiator or valve.

• Address an unwanted draught while preserving necessary ventilation.

• Try an approved alternative position for a wireless thermostat.

Repeat the comparison under reasonably similar conditions.

An illustrative result

Suppose the thermostat area measures 21°C while the seating area measures 18.5°C.

After clearing a blocked radiator, the seating area reaches 19.5°C while the thermostat area remains similar.

Those are example figures, not promised results. They illustrate the useful finding: comfort may improve without a higher thermostat setting.

Remember that weather, sunlight, cooking and open doors can affect the comparison. Treat this as a household investigation, not a laboratory test or proof of bill savings.

Your 15-Minute Heating Check

You can complete the initial inspection in 15 minutes, even though temperature measurements and follow-up comparisons take longer.

Time	Check	What you are looking for
Minutes 1–3	Walk around radiators and other heat emitters	Furniture, curtains and covers restricting heat distribution
Minutes 4–6	Inspect the thermostat and sensor position	Draughts, sunlight, nearby heat sources and obstructions
Minutes 7–9	Review the heating programme	Incorrect clock, outdated routines and repeated boosts
Minutes 10–12	Identify the controls	Room temperature, heating flow temperature and hot-water settings
Minutes 13–15	Set up the thermometer comparison	A useful comparison between the control location and occupied space

Make one straightforward improvement first.

If rooms remain persistently uneven, the next step may be a heating engineer checking radiator balance, circulation, controls or heat-emitter sizing.

Before You Turn It Up, Understand What It Is Doing

A warm home depends on the heating system and the building working together.

Clear radiators help warmth circulate. A sensibly positioned thermostat gives the controls useful information. Suitable flow temperatures and schedules help the equipment meet the household’s needs.

As a science teacher, I like the approach of observing first, changing one thing and checking the result. It is useful in the laboratory—and just as useful when investigating a chilly sitting room.

You do not need a collection of smart gadgets to begin. Two thermometers, a little curiosity and a walk around the house can reveal a surprising amount.

Before increasing the thermostat, give your heating 15 minutes of attention. You may discover that the warmth you need is already being produced—it simply needs a clearer route to you.