Case Study: Replacing a Gas Boiler with Invisible Ceiling Infrared Heating in a 100m² Home

This UK residential renovation demonstrates how a homeowner successfully replaced a traditional gas boiler and wall-mounted radiator system with a fully electric, iHelios invisible infrared ceiling heating system. 

Operating as a key low-carbon installation in Yorkshire, the homeowner sought to eliminate wet pipework hazards, free up wall space, and achieve localized room-by-room climate control using modern smart automation. By pairing the 0.50 mm ultra-thin iHelios heating film directly with local time-of-use energy tariffs and a 20 kWh home storage battery, the project establishes a highly replicable roadmap for off-gas home developments across the UK.

Project overview

This residential project shows how a homeowner replaced a traditional gas boiler and radiator system with a fully electric, invisible infrared ceiling heating system.

The homeowner wanted to remove the boiler, radiators and water-filled pipework completely. They also wanted independent control in every room and a heating system that could work alongside battery storage and future solar PV.

iHelios designed a multizone ceiling heating system for the 100 m² property using 500 mm iH405 infrared heating film.

The finished installation has a total connected heating output of 7.4 kW, divided across eight independently controlled zones.

Electricity bills from the property show that total household consumption reached a maximum of approximately 35 kWh per day during winter, including heating, hot water, cooking, lighting, appliances and all other electrical demand.

Project summary

Project detail	Specification
Property type	Residential home
Property size	100 m²
Primary heating system	iHelios invisible ceiling infrared heating
Heating film	500 mm iH405 infrared heating film
Installation method	Concealed within the ceiling construction
Total connected heating output	7.4 kW
Heating zones	8 independent zones
Smart thermostats	8
Heating schedule	Up to 8 hours per day
Previous heating system	Gas boiler and radiators
Battery storage	20 kWh
Usable battery capacity	Approximately 18 kWh at 90%
Overnight electricity tariff	Approximately 7p/kWh
Daytime electricity tariff	Approximately 26p/kWh
Maximum verified winter electricity use	Approximately 35 kWh per day
Estimated heating share	Approximately 60%
Solar PV	Planned for future installation

Infrared Heating Running Costs UK: 100m² Home 

For this 100m² UK home, the maximum verified winter electricity consumption was approximately 35 kWh per day, including infrared heating, hot water, cooking, lighting, appliances and other household electricity use.

Space heating is estimated to account for approximately 21 kWh per day, although the heating was not separately sub-metered.

At a standard daytime electricity rate of 26p per kWh, the estimated infrared heating cost would be approximately £5.46 per day, or £163.80 over a 30-day winter month.

By using a 20 kWh battery charged overnight at approximately 7p per kWh, the illustrative heating cost could be reduced to around £2.04–£3.41 per day, depending on how the stored electricity is allocated across heating and other household demand.

These figures are specific to this property. Infrared heating running costs vary according to the building’s heat loss, insulation, installed output, thermostat settings, heating schedules, local weather and electricity tariff.

The homeowner’s objectives

The homeowner wanted to move away from gas and create a fully electric home.

Their priorities were to:

• remove the gas boiler permanently;
• eliminate radiators and heating pipework;
• recover usable wall space;
• control every room independently;
• avoid heating unused rooms;
• use lower-cost overnight electricity;
• integrate battery storage;
• prepare the property for future solar PV;
• reduce maintenance associated with boilers and wet heating systems.

Rather than replacing the existing boiler with another central heating appliance, the homeowner chose a distributed heating system controlled separately in each room.

Why ceiling infrared heating was selected

The homeowner wanted a heating system that would not affect furniture placement or interior design.

The iHelios heating film was installed within the ceiling construction and concealed behind the finished ceiling surface. Once installed, there are no visible heating emitters in the rooms.

The ceiling system provides radiant heat to room surfaces, furniture and occupants while also warming the surrounding air.

The installation removes the need for:

• wall-mounted radiators;
• heating pipes;
• a circulation pump;
• a gas boiler;
• annual boiler servicing.

The ceiling remained available across the property, making it a practical location for distributing the heating output without reducing usable floor or wall space.

Heating-system design

The property has a total area of approximately 100 m².

The complete heating system has a connected output of 7.4 kW, equivalent to an average of approximately 74 W per square metre across the property.

This figure represents the total available system output. It does not mean the property continuously consumes 7.4 kW whenever the heating is scheduled.

The installed output was distributed across eight heating zones. Each zone is controlled by its own thermostat, allowing rooms to reach temperature and switch off independently.

Actual electricity consumption depends on:

• outdoor temperature;
• room heat loss;
• insulation;
• glazing;
• thermostat setpoints;
• occupancy;
• room schedules;
• internal heat gains;
• the number of zones calling for heat simultaneously.

Eight-zone smart control

The property was divided into eight independently controlled heating zones, each with its own smart thermostat.

This allows the homeowner to set different temperatures and operating times for different rooms.

For example, living areas can be heated during the morning and evening, while bedrooms can follow shorter schedules based on occupancy.

The control strategy provides:

• individual room temperatures;
• separate schedules;
• heating only where required;
• lower temperatures in unused rooms;
• less unnecessary whole-house heating;
• more precise comfort control.

This is an important distinction from a traditional centrally controlled boiler system, where several rooms may be heated together even when they are not all being used.

Scheduled operation

The heating system is scheduled for up to approximately eight hours per day during winter.

However, the heating film does not remain continuously energised throughout those eight hours.

Each thermostat switches its own zone on and off as the room reaches and maintains the selected temperature.

If the complete 7.4 kW system operated continuously for eight hours, the theoretical maximum heating consumption would be:

7.4 kW × 8 hours = 59.2 kWh

That scenario would require every zone to call for heat continuously during the entire scheduled period.

The property’s electricity bills show that the complete household—including heating and every other electrical load—used no more than approximately 35 kWh per day during the highest winter-use period.

This confirms that the heating system does not operate continuously at its full connected output.

Verified winter electricity use

The maximum winter electricity consumption of approximately 35 kWh per day is based on the customer’s electricity bills.

This figure covers the complete home and includes:

• infrared space heating;
• domestic hot water;
• cooking;
• lighting;
• appliances;
• battery and inverter losses;
• general household electricity use.

Space heating is estimated to account for approximately 60% of the total winter electricity consumption.

Estimated heating share

35 kWh × 60% = approximately 21 kWh per day

The remaining household electricity consumption is therefore approximately:

35 kWh − 21 kWh = approximately 14 kWh per day

Electricity use	Daily consumption
Estimated infrared space heating	21 kWh
Other household electricity	14 kWh
Verified maximum total winter consumption	35 kWh

The 35 kWh figure is verified from electricity bills. The split between heating and other household use is an estimate because the heating system is not separately sub-metered.

Estimated heating duty cycle

The complete system could theoretically consume 59.2 kWh during an eight-hour schedule if all zones remained on continuously.

Estimated actual heating use is approximately 21 kWh per day.

The implied average equivalent duty cycle is therefore:

21 kWh ÷ 59.2 kWh = approximately 35.5%

This means that, across the scheduled heating period, the zones operated at an average equivalent duty cycle of approximately 35%.

Some rooms may run longer than others, and individual zones will cycle at different times depending on heat loss, temperature settings and occupancy.

Electricity cost without battery shifting

The daytime electricity rate is approximately 26p per kWh.

If the complete 35 kWh daily household consumption were purchased at this rate, the cost would be:

35 kWh × £0.26 = £9.10 per day

Over a 30-day winter month:

£9.10 × 30 = £273.00

This is the estimated cost for the property’s complete electricity consumption, not heating alone.

Estimated heating cost at the daytime rate

If heating accounts for approximately 21 kWh per day:

21 kWh × £0.26 = £5.46 per day

The remaining 14 kWh of household demand would cost:

14 kWh × £0.26 = £3.64 per day

Together, these produce the total daily cost of £9.10.

Battery storage and overnight charging

The property has a 20 kWh battery energy storage system.

Using 90% of the stated capacity provides approximately:

20 kWh × 90% = 18 kWh of usable stored energy

The battery is charged overnight at approximately 7p per kWh.

The cost of charging 18 kWh overnight is:

18 kWh × £0.07 = £1.26

With maximum total household consumption of 35 kWh per day, the remaining daytime grid requirement is approximately:

35 kWh − 18 kWh = 17 kWh

The cost of the remaining electricity at 26p per kWh is:

17 kWh × £0.26 = £4.42

Realistic maximum daily household cost

Energy source	Consumption	Rate	Cost
Overnight battery charging	18 kWh	7p/kWh	£1.26
Remaining daytime grid electricity	17 kWh	26p/kWh	£4.42
Total household electricity use	35 kWh	—	£5.68 per day

Over a 30-day winter month:

£5.68 × 30 = approximately £170.40

Compared with purchasing all electricity at the daytime rate, this represents an illustrative reduction of:

£273.00 − £170.40 = £102.60 per month

The battery and time-of-use tariff reduce the estimated maximum daily electricity cost by approximately 38%.

Realistic heating-cost allocation

Heating is estimated to represent approximately 60% of total winter electricity use.

If 60% of the battery-adjusted household cost is allocated to heating:

£5.68 × 60% = approximately £3.41 per day

Over a 30-day winter month:

£3.41 × 30 = approximately £102.30

This is a proportional allocation rather than a separately metered heating cost.

Another way to illustrate the potential heating cost is to assume that the stored overnight electricity is used to cover the heating demand first.

Estimated heating demand:

21 kWh per day

Battery contribution:

18 kWh at 7p = £1.26

Remaining heating demand:

3 kWh at 26p = £0.78

Illustrative space-heating cost:

£1.26 + £0.78 = approximately £2.04 per day

In practice, the battery supplies the entire home dynamically, including hot water, lighting, cooking and appliances. The actual heating cost therefore sits within the overall household electricity bill rather than being charged separately.

Why installed output and electricity consumption are different

A common misunderstanding is to assume that a 7.4 kW heating system consumes 7.4 kWh every hour throughout the day.

The 7.4 kW figure is the maximum connected output available if all eight heating zones operate simultaneously.

Actual consumption is lower because:

• every room has a separate thermostat;
• rooms operate on different schedules;
• zones switch off after reaching temperature;
• not all rooms call for heat at the same time;
• internal heat gains reduce heating demand;
• occupancy patterns vary throughout the day.

The verified electricity bills provide a more realistic picture than simply multiplying the connected output by the number of hours in a day.

Previous heating system

Before the installation, the property relied on a gas boiler and wall-mounted radiators.

The previous arrangement included:

• a central boiler;
• water-filled pipework;
• radiators occupying wall space;
• centralised heating control;
• annual boiler servicing;
• ongoing dependence on gas.

The new system removes these components and replaces them with concealed electric heating divided into eight independently controlled zones.

Before and after

Before	After
Gas boiler	Fully electric infrared heating
Wall-mounted radiators	Invisible ceiling heating
Wet pipework	No heating water circuit
Centralised heating	Eight independent zones
Boiler servicing	No annual boiler service
Limited wall space	Walls free from radiators
No battery integration	20 kWh battery storage
Fossil-fuel heating	All-electric heating strategy
No solar integration	Solar PV planned

Preparing for future solar PV

Solar PV had not yet been installed when the winter electricity bills were recorded.

The homeowner plans to add rooftop solar panels in the future.

Once installed, the solar system will be able to:

• supply part of the daytime household load;
• reduce electricity imported from the grid;
• charge the battery using surplus solar generation;
• support heating during suitable daylight conditions;
• increase the use of self-generated electricity.

Solar generation will vary by season and weather. It should not be assumed that rooftop solar will cover the full winter heating requirement, but it can reduce annual grid consumption and improve the overall performance of the all-electric energy system.

Results

The completed project has delivered:

• full removal of the gas boiler;
• no wall-mounted radiators;
• no wet heating pipework;
• concealed ceiling heating;
• eight independently controlled zones;
• eight smart thermostats;
• scheduled heating for up to eight hours per day;
• a 7.4 kW total connected output;
• verified maximum winter household electricity use of approximately 35 kWh per day;
• estimated space-heating use of approximately 21 kWh per day;
• a 20 kWh battery with approximately 18 kWh usable capacity;
• lower-cost overnight battery charging;
• preparation for future solar PV;
• more usable wall space;
• reduced mechanical heating-system maintenance.

Important evidence note

The maximum winter electricity consumption figure of approximately 35 kWh per day is based on the property’s electricity bills.

The estimated allocation of 60% to space heating is based on the heating schedules, thermostat operation and the household’s other electrical loads. It is not based on separate heating sub-metering.

The cost calculations use electricity rates of:

• approximately 7p/kWh for overnight charging;
• approximately 26p/kWh for daytime electricity.

The calculations exclude standing charges because these apply regardless of which heating system is installed.

Battery conversion losses, reserve settings and tariff variations may also affect actual costs.

Conclusion

This case study demonstrates how a 100 m² home moved away from a traditional gas boiler and adopted a fully electric, invisible ceiling heating system.

The property now uses 500 mm iH405 infrared heating film with a total connected output of 7.4 kW, divided into eight independently controlled zones.

Although the system can provide 7.4 kW when all zones call for heat, it does not operate continuously at full output. Electricity bills show that maximum total winter household use remained at approximately 35 kWh per day, including heating and every other electrical demand in the property.

Heating is estimated to represent approximately 21 kWh per day, equivalent to an average duty cycle of around 35% across the scheduled eight-hour heating period.

By charging approximately 18 kWh of usable battery capacity overnight at 7p/kWh, the illustrative maximum total household electricity cost is reduced from around £9.10 to approximately £5.68 per day.

The planned addition of solar PV will complete the homeowner’s wider strategy of combining electric heating, battery storage and onsite renewable generation.

Planning to replace your gas boiler?

Every property has different heating requirements. Floor area alone is not enough to specify the correct installed output.

iHelios designs invisible ceiling and underfloor infrared heating systems using room dimensions, construction details, glazing, insulation, intended temperatures and room-by-room heat-loss requirements.

Contact iHelios Living Reinvented to discuss a boiler-free heating system for your home, renovation or development.