Electric boiler vs. ORAVA convector – which heating type is more cost-effective
Electric boiler vs. ORAVA convector – which heating type is more cost-effective?
This question arises regularly – whether during the renovation of an apartment, equipping a cottage, or when deciding what to do with heating in an old house where gas or hot water is not an option. An electric boiler and an electric convector appear to be similar solutions: both run on electricity, both produce heat. But they work differently, suit different situations, and their operational logic is fundamentally different. In this article, we will go through the entire issue systematically – the technology, economics, installation, regulation, and real-life scenarios – so that you can know exactly at the end which solution makes sense for you.
How an electric boiler and a convector work – basic principle
Before comparing costs or performance, it is important to understand what physically happens in each device. Both types convert electricity into heat with an efficiency close to 100% (no combustion engine can achieve this), but the way this heat is delivered into the room is fundamentally different.
Electric boiler – central heat via water
An electric boiler heats water that circulates in a closed loop through radiators, floor pipes, or other surfaces. The boiler has an electric resistance element (or an electrode system), an expansion tank, a circulation pump, and control electronics. In principle, it is the same system as gas or wood-fired central heating – only the heat source is electric. Examples from the ORAVA portfolio: ORAVA EK-2003 and ORAVA EK-2004 are high-performance electric boilers specifically designed for this type of installation.
Convector – direct heat without water
A convector is a standalone unit with no piping at all. It contains an electric resistance element and a fan (forced convection) or just natural air flow (gravitational convection). Air enters from the bottom, passes around the element, is heated, and exits upwards. Each room has its own unit, and each unit has its own thermostat. Examples: ORAVA VL-202 or ORAVA VL-201 are typical wall-mounted convectors of this type.
When an electric boiler and when a convector makes sense
This is the key question, and the answer depends on the specific situation. There is no universal "better" solution – it depends on the type of property, the habits of the residents, the available electrical connection, and future plans for the building.
An electric boiler is suitable when:
- You have an existing water and radiator piping system – for example, you have been heating with gas and want to only change the heat source without interfering with the piping. ORAVA boiler can be easily "plugged" into the existing loop.
- You want floor heating – a convector has nothing to do with floor heating; a boiler does.
- You are heating a larger house (100 m² and more) – for larger areas, a central system is more efficient than dozens of individual units.
- You need hot water for domestic use – some boilers allow you to connect a water heater or storage heater.
- You do not want to have visible electrical devices in every room – radiators are more discreet than wall-mounted convectors.
- You plan to combine with solar collectors – a boiler can serve as an additional source to a solar system.
A convector is suitable when:
- You have no water piping at all and do not want to build it – installation of a convector takes an hour, installation of a water system takes weeks and thousands of euros.
- You are heating occasionally – a cottage, a summer house, a recreational building, where you need heat quickly and only when you are there.
- You are heating individual rooms selectively – with a boiler you heat the whole house at once, with convectors only where you need it.
- You have a low installation budget – a convector costs a few hundred euros, does not require an electrician beyond a 230 V socket (for smaller models), and you can install it yourself (see the article ORAVA Convector Wall Mounting – Guide and Common Installation Mistakes).
- You are renting out the property – each tenant regulates separately, simple billing.
- Heating is supplementary – for example, during the transitional period or in the absence of the main source.
Technical parameters – what do performance and dimensions say
Let’s look at the specific numbers. When choosing an ORAVA electric boiler, we are dealing with power classes from 4 kW to 24 kW (see the article What ORAVA electric boiler power do I need for my household). A well-insulated family house with a floor area of 120 m² needs about 8–12 kW at an outside temperature of −15 °C. ORAVA EK-2003 and ORAVA EK-2004 cover exactly this segment – these are compact boilers suitable for family houses and smaller apartment buildings.
ORAVA convectors typically range from 1,000–2,500 W per unit. ORAVA VL-202 is a more powerful model with a larger radiation surface, ORAVA VL-201 is a more compact variant for smaller spaces or supplementary heating. To cover 120 m² with convectors only, you need 6–8 units – at 1,500 W per unit, this totals 9–12 kW. The result is the same, but the way to achieve it is completely different.
Installation costs – where the difference is most noticeable
This is one of the biggest practical differences. An electric boiler requires complex installation: an electrical connection with circuit breakers for 3× 16 A to 3× 32 A (three-phase!), installation into an existing or new water circuit, system air venting, pressure setting, possibly installation of an expansion tank and a safety valve. Electrical work is mandatory – this is a legal requirement. More about this procedure can be found in the article "Installation of ORAVA electric boiler – procedure, requirements and what the electrician must do."
Total installation costs for an electric boiler when replacing a gas boiler in an existing house with existing piping: electrical work 200–400 €, possible piping modifications 100–300 €, the boiler itself 500–1,200 €. In total, 800–1,900 €, sometimes even more.
A convector is dramatically simpler in this respect. A smaller model (up to 1,500 W) can be plugged into a standard 230 V socket. A larger one (2,000–2,500 W) is recommended to be on a separate circuit, but it is still a single-phase connection. Wall mounting can be done by a skilled owner in an hour. Costs: the convector itself 80–250 €, a possible socket 30–60 €. If you need more units, the cost increases linearly – but it is still lower than the cost of a boiler system.
Energy consumption and operating costs – myths and reality
This is the point where many people make a mistake. Both devices have an electrical efficiency close to 100% – this means that every watt of electricity is converted into a watt of heat. Neither the boiler nor the convector "wastes" any energy. So if you heat the same room to the same temperature, the consumption will be identical regardless of whether you use a boiler or a convector.
Where then does the difference in costs arise? Exclusively in the regulation and behavior of the system.
Regulation with a boiler
The boiler heats the entire water circuit. When the boiler is turned on, it heats water for all radiators at once. Although you can have thermostatic heads on individual radiators, the entire system reacts slowly – the water volume has a large thermal inertia. This is an advantage for continuous heating (temperature is stable, the boiler does not cycle in short intervals), but a disadvantage for selective heating. When you leave the house, the boiler still has to take care of the entire system – you cannot simply "turn off the bedroom and keep only the living room."
Regulation with convectors
Each convector has its own thermostat. A room that is unoccupied can simply be turned off or set to 15 °C. The bedroom at night can be at 18 °C, the living room during the day at 22 °C. This zonal regulation is a source of real savings when used properly – not because the convector is more efficient physically, but because it consumes energy only where and when you actually need it.
More on this topic can be found in the articles "Regulation and temperature setting of ORAVA convectors – how to properly control heating" and "ORAVA electric heating and energy consumption – how to reduce heating costs."
Heating speed and thermal inertia
A convector reacts almost instantly – within 5–10 minutes, the room becomes noticeably warmer. With fan convectors, the temperature rise is even faster. This is important for occasional heating: you arrive at a cottage on Friday evening and within an hour it is warm.
An electric boiler with a water circuit needs time to heat the entire water volume in the system – in a typical family house, this can be 30–60 minutes before the radiators start to give off significant heat. This is not a disadvantage for daily continuous heating (the system runs continuously and only modulates the temperature), but when "turning on after a week" you will feel it.
For this reason, a convector is practically always a better choice for seasonal recreational properties. For permanently occupied family homes, a water circuit with a boiler is more comfortable and more cost-effective in continuous operation (lower heating cycle frequency = lower heat losses).
Lifespan and Maintenance Costs
An electric boiler has more moving and potentially faulty components: a circulation pump, expansion tank, safety valve, temperature and pressure sensors, and control electronics. An annual inspection is recommended and necessary (more in the article "Maintenance and Service of ORAVA Electric Boilers – What and How Often to Check"). The lifespan of a well-maintained boiler is 15–20 years, but the pump or electronics may need to be replaced sooner.
A convector is much simpler – it has only a resistive element, thermostat, and possibly a fan. It does not contain water, so no bleeding is required, and there is no pump. Routine maintenance is minimal: cleaning from dust once per season. The lifespan of convector without a fan (gravity type) can be 20–30 years, while models with a fan have the fan as the weakest component, but its replacement is cheap. In the case of ORAVA electric boiler failures (more in the article "Common Failures of ORAVA Electric Boilers and How to Eliminate Them"), these are often exactly these secondary components.
Safety and Space Requirements
An electric boiler must be installed in accordance with the current STN standards. It requires a circuit breaker, surge protector, and grounding conductor. The space for the boiler must be accessible for service. The boiler must not be in a humid environment without appropriate IP protection. All these requirements are discussed in detail in the article "How to Choose an ORAVA Electric Boiler or Convector – What to Focus On."
A convector is simpler in terms of safety – it is a consumer similar to an electric stove. It must not be covered by curtains or furniture (risk of overheating), and must not be in a bathroom without appropriate IP protection. Otherwise, it does not require any special conditions.
Combination of Both Systems – Practice from the Field
In practice, we encounter many combined solutions. A typical example: an older family house with boiler heating, where two rooms are poorly heated (garage, workshop, winter garden). Instead of extending the piping, it is much simpler to install an ORAVA convector as an additional source for these areas only.
Another common scenario: an apartment building with central heating, where bathroom radiators are disconnected due to renovation. During the transitional period, we install a convector as a temporary solution – in 90 minutes of installation, you have heat without waiting for the renovation.
Or the other way around: a customer had convectors throughout the house, but decided to undergo a comprehensive renovation. On this occasion, we designed a transition to an electric boiler with underfloor heating. The initial investment is higher, but the resulting comfort and aesthetics of the apartment space are significantly better.
Influence of Electricity Tariffs on System Cost-Effectiveness
Electric boilers in power classes above 7 kW usually allow the use of low tariff (NT) – in Slovakia, this is tariff D6 or D7, where the distributor guarantees a minimum number of hours of cheaper electricity in exchange for the right to interrupt the supply. For a boiler with storage (boiler + tank), this tariff is a key economic factor – the night cheaper electricity is "stored" in the tank and heating is done during the day without turning on the boiler.
Convector units do not work well with NT tariffs – they are too small for the distributor to agree to the interruption, and they lack storage. It is possible to use storage electric stoves, but these are a different category of products.
This is the reason why, in permanent operation in a family house, an electric boiler with NT tariff is cheaper than convectors on full tariff – even though the physical efficiency is the same. The price difference between VT and NT electricity can be 40–60 %, which is significant for consumption of 15 000–20 000 kWh per year.
Aesthetics and Comfort in Interior
This is an underestimated aspect. Convector units are visible wall-mounted devices – they are aesthetically designed (modern ORAVA models have clean lines), but they take up part of the wall space and require free space in front of them (furniture must not be placed there). In a smaller apartment, 4–5 convectors can be visually disturbing.
Radiators powered by a boiler are traditional and well-established in interiors. With underfloor heating, nothing is visible at all. From the perspective of interior design, boiler systems have a clear advantage in more complex setups.
Practical Summary – Comparison Table
| Criterion | ORAVA Electric Boiler | ORAVA Convector |
|---|---|---|
| Installation costs | High (800–2 000 €+) | Low (100–300 €) |
| Heating speed | Slower (30–60 min) | Fast (5–15 min) |
| Zonal regulation | Limited (TRV heads) | Perfect (each room) |
| NT tariff | Yes (D6, D7) | No |
| Underfloor heating | Yes | No |
| Maintenance | Annual inspection required | Minimal |
| Suitability – cottage/cabin | Less suitable | Ideal |
| Suitability – permanent residence | Ideal | Acceptable |
| Lifespan | 15–20 years | 20–30 years |
Real-life scenarios from practice – concrete examples
Scenario 1: Old family house, replacement of gas boiler
The customer has a house built in 1985, with a complete water distribution system and steel sectional radiators. The gas connection was removed during the street reconstruction. Ideal choice: electric boiler ORAVA EK-2004, which can be easily connected to the existing system. The electrician installed a 3× 16 A supply, we set up the boiler and started the low tariff D6. The customer saved on installation, as no construction work was required – only electricity and the boiler.
Scenario 2: Recreational cabin, 60 m², irregular stays
The owner visits the cabin 2–3 times a month during the winter season. The house has no distribution systems, only a 230 V electrical connection. Solution: 4 ORAVA convector heaters – a larger model VL-202 in the living room and smaller models VL-201 in the bedrooms and bathroom. Total power of 6 kW is sufficient for a well-insulated 60 m² cabin. When he arrives on Friday evening, it reaches 22 °C within an hour. During absence, it is set to 5 °C (frost protection). Installation took one day, no plumber, no electrician (just standard sockets).
Scenario 3: New apartment, heating not included by the developer
Modern 75 m² apartment on the fourth floor, central heating is in the project but not yet commissioned. The customer needed heating immediately. Temporary solution: 3 ORAVA convector heaters in the living room, bedroom and children’s room. After the central heating is commissioned, the convector heaters remain as backup and supplementary – for evening heating in the children’s room, and on corridors during extreme cold.
Scenario 4: House with a combination – boiler + convector heaters on the periphery
Large house of 180 m², electric boiler with floor heating for the living room, dining room and bathrooms. The garage, workshop and winter garden were not included in the distribution system. For these three areas, we added separate convector heaters – garage 2× 1 500 W, workshop 1× 2 000 W, garden 2× 1 500 W. Each convector has its own thermostat and is turned on only when the space is used. A hybrid approach was the most economically and technically sensible in this case.
Most frequently asked questions (FAQ)
Is an electric boiler more expensive to operate than a convector?
Not automatically. Both devices have an electrical efficiency close to 100 %. A boiler can be cheaper to operate if it draws from a low tariff (NT), which a convector usually cannot. At full tariff and the same power, the consumption is identical. The difference is made by proper regulation and zonal control, not the type of device.
Can I replace a boiler with convector heaters in the whole house?
Technically yes, but it is not always reasonable. For houses over 100 m² with permanent living, a boiler with NT tariff is more economically advantageous in the long term. Convector heaters are suitable for smaller areas, occasional heating or as a supplement to another system.
Does the installation of ORAVA convector heater require an electrician?
Smaller convector heaters up to 1 500 W with a standard 230 V plug do not require a professional electrician for connection – you can plug them in yourself. Wall mounting is mechanical and you can do it yourself according to the instructions (see the article Wall mounting of ORAVA convector heater – instructions and common installation errors). Larger models with fixed connection (without a plug) must be connected by an electrician.
How many convector heaters do I need for a house of 80 m²?
As a rough estimate, calculate 50–75 W per 1 m² for a well-insulated house (standard for Slovakia), which for 80 m² gives a total power of 4 000–6 000 W. With 1 500 W convector heaters, this means 3–4 units. Each convector for one room or zone. The exact calculation depends on the heat losses of the specific building.
Can an ORAVA electric boiler be connected to an existing gas pipeline?
No, an electric boiler is connected to an existing water circuit (radiators, floor heating), not to the gas pipeline. The gas pipeline is not part of the electric boiler – it is used only for gas appliances. Replacing a gas boiler with an ORAVA electric boiler is a common job, where the entire water distribution system is preserved and only the heat source is changed.
What is more advantageous for rental – a boiler or convector heaters?
For rental purposes, convector heaters are more practical: each tenant has their own control over the temperature in their part of the property, there is no problem with billing for the consumed energy (each pays for their own electricity), and installation is simple and does not require the landlord to be responsible for the boiler system. For long-term rental of the whole house, a boiler is acceptable, but it requires an agreement on maintenance.
Conclusion – which type of heating is really worth it?
The ORAVA electric boiler is worth it when you have permanent living, an existing or planned water distribution system, the possibility of drawing from a low tariff and an interest in a comfortable, centrally controlled heating system. It is a long-term solution with a higher initial investment, but more economical operation with NT tariff and for large heated areas.
The ORAVA convector heater is worth it when you need a fast, flexible, low-cost installation solution – for a cabin, supplementary heating, an apartment without distribution systems or spaces with occasional use. Low initial investment and no need for engineering networks are its main advantages.
In many cases, the choice is not exclusive – a combination of a boiler for permanent living areas and convector heaters for peripheral zones is a technically and economically elegant solution that uses the strengths of both systems. If you are unsure, take a look at the full category ORAVA electric boilers and convector heaters and compare the products directly with their technical specifications. We always recommend consulting with an installation company for a comprehensive assessment of your situation, as they know the real heat losses of your specific property.
Do you have a question about this topic?
Can't decide or are you dealing with a specific situation in your household? Write to us – we are happy to help.