Electric heating ORAVA and energy consumption – how to reduce heating costs
Electric heating ORAVA and energy consumption – introduction to the topic
Electric heating is today one of the most popular alternatives to classic gas boilers, especially in smaller households, cottages, offices or homes where gas is not available. Products from the ORAVA brand – whether electric boilers of the EK series or convectors of the VL series – represent an affordable, easy to install and surprisingly efficient solution, provided the system is used correctly. This "correct" use is the key to whether your monthly electricity bills will remain at a reasonable level or will unpleasantly surprise you every February.
In practice, I have encountered dozens of households where electricity was originally considered an expensive way of heating – and yet after setting up the correct programs, zoning the rooms and replacing old direct heaters with modern convectors with a thermostat, energy consumption dropped easily by 20 to 35 %. This article will show you where energy is lost, how to measure and monitor consumption, and above all – what specific steps you can take to pay less for heat.
How to actually calculate the consumption of an ORAVA electric boiler or convector
Before we start talking about savings, we need to be able to orient ourselves in the numbers. The basic formula is simple: energy consumption (kWh) = device power (kW) × operating hours. However, in practice it is not that simple, because modern electric boilers and convectors do not run at full capacity all the time – they regulate the power according to current needs and outside temperature.
Let’s take a concrete example. ORAVA EK-2003 is an electric boiler with a power of 3 kW. If it ran continuously for 24 hours, it would consume 72 kWh per day. At an electricity price of 0.22 €/kWh, this would amount to 15.84 € per day – which sounds alarming. But in real operation, a regulated boiler with a thermostat typically runs at 30–50 % of its capacity. In other words, in a well-insulated apartment with an area of 30 m² and a ceiling height of 2.5 m at an outside temperature of –5 °C, a boiler with a room thermostat might run for 8–12 hours a day at full power or 16–20 hours in 30/70 cycles (30 % running time, 70 % pause). The actual daily consumption would thus be around 12–18 kWh, which is a completely different number.
Convectors of the VL series work on the same principle, but are even more sensitive to immediate conditions in the room. ORAVA VL-202 is a wall-mounted convector intended for local heating – it functions as a standalone unit for one room and its consumption depends directly on the heat loss capacity of the room (windows, walls, orientation). Therefore, when calculating consumption, you can never rely solely on the rated power – it is always necessary to take into account the building's heat losses.
Power vs. actual consumption – percentage load
In practice, I often encounter the situation where customers buy a boiler or convector with a power of 2 kW and expect to pay for 2 kW every hour. The reality is different. With a well-insulated room and properly set desired temperature, the average load is around 25–45 %. This means that 0.5–0.9 kWh is actually consumed per hour, not 2 kWh. It is precisely in this that electric heating with modern regulation is much more economical than it seems at first glance.
Where the most energy escapes – heat loss in practice
No saving measures on the boiler side will help if the building is losing heat like a sieve. This is something field technicians know very well – the customer buys a new modern convector, but the walls are not insulated, the windows are not airtight and the roof is not insulated. Result? The boiler or convector runs at 90 % power almost continuously and the electricity bill is astronomical.
Overview of typical heat losses in a standard house
- Roof and ceiling: 25–30 % of total heat losses. Warm air rises upwards and if there is no proper insulation, it escapes outside.
- Walls: 20–25 % of losses. Old, non-insulated masonry has poor thermal insulation properties.
- Windows and doors: 15–20 % of losses. A single old single-glazed window will lose a huge amount of energy during winter.
- Floor: 10–15 % of losses. Especially in ground floor without a basement or with an unheated basement.
- Thermal bridges and leaks: 5–15 % of losses. Frames, corners, intersecting structures.
In practice, this means that if you invest in insulation or window replacement before solving the heating type, you can reduce the required boiler or convector power by 30–50 %. For the correct selection of power, also read our article "What power of ORAVA electric boiler do I need for my household?", where there are specific calculation formulas.
Control as the most powerful tool for energy saving
If I had to choose one measure in practice that most quickly and effectively reduces the cost of electric heating, it would be control. Not insulation, not a new boiler – but properly set control of the existing system. Why? Because every additional degree Celsius compared to the optimal temperature increases consumption by 5–7 %.
If you maintain 23 °C in the living room instead of 20 °C, you pay 15–21 % more. Over the entire heating season, this can be the difference of hundreds of euros. And yet, most people hardly notice the difference between 20 °C and 22 °C – they just put on a sweater and save.
Recommended temperatures for individual rooms
| Room | Recommended temperature | Night/Reduced temperature |
|---|---|---|
| Living room, dining room | 20–21 °C | 16–18 °C |
| Bedroom | 17–19 °C | 15–16 °C |
| Bathroom | 22–24 °C | 18–20 °C |
| Children's room | 20–22 °C | 18 °C |
| Hallway, entrance | 15–17 °C | 12–14 °C |
| Office | 20–21 °C | 15 °C (when not working) |
| Garage, basement | 5–8 °C (anti-frost protection) | 5 °C |
Weekly time program – specific setting
ORAVA EK series electric boilers are equipped with a built-in thermostat with programming capability. A properly set weekly program could be like this for a typical family with children in school and working adults:
- Mon–Fri 6:00–7:30 – comfort mode 21 °C (morning waking up and departure)
- Mon–Fri 7:30–15:00 – reduced mode 16 °C (empty household)
- Mon–Fri 15:00–22:00 – comfort mode 21 °C (return home, evening)
- Mon–Fri 22:00–6:00 – night reduced mode 17 °C (sleeping)
- Sat–Sun 7:00–23:00 – comfort mode 21 °C
- Sat–Sun 23:00–7:00 – night reduced mode 17 °C
Savings compared to a non-programmed mode with a constant temperature of 21 °C: typically 18–28 % depending on the building's insulation properties and area. With an annual consumption of 4,000 kWh, this means a saving of 720 to 1,120 kWh, which at a price of 0.22 €/kWh represents 158 to 246 € annually.
Low rate (NT) of electric energy and ORAVA electric boilers
In Slovakia, distribution companies offer several tariff bands. A two-band tariff (D45p, D56p or similar) allows the use of cheaper night tariff (NT) during certain hours – typically at night and on weekends. The difference between HT (high tariff) and NT (low tariff) is usually 30–45 % depending on the distributor and tariff.
ORAVA electric boilers connected to a system with a hydraulic accumulator (heat storage) can "charge" water to a higher temperature at night and use this accumulated energy during the day – similar to a water heater. This solution is especially advantageous for electric central heating with radiators. ORAVA EK-2004 is a high-power boiler suitable precisely for such central connections in a family house or larger apartment.
Important: to be able to invoice electricity in a two-band tariff, you must have an installed switchboard with HDO receiver and the boiler must be connected to a circuit that the distribution company controls – this is also discussed in our article "Installation of ORAVA electric boiler – procedure, requirements and what the electrician must do".
Zonal heating – heat only where you need it
One of the biggest mistakes I see in practice is heating the entire house or apartment evenly to the same temperature regardless of whether someone is present in a given room. Hallways, basements, garages, guest rooms – these are areas where frost protection or significantly lower temperatures are sufficient.
ORAVA VL convectors are ideal for zonal heating, as each room has its own separate unit with its own thermostat. ORAVA VL-201 is a compact wall-mounted convector suitable for smaller rooms such as a bedroom, office, or guest room – you can turn it on only when the room is actually in use. Compared to central gas heating, where the entire house is heated at once, this is a significant advantage.
Practical example: a customer had a 5-room house where the guest room and garage were heated the same way as the living room. After switching to convectors with individual control and setting frost protection (5 °C) in the garage and low-temperature mode (15 °C) in the guest room, monthly consumption dropped by 22 % – purely through setting changes, without any construction work.
Practical tips for reducing energy consumption with ORAVA electric heating
1. Leaks and ventilation
Every air leak in the building envelope means uncontrolled heat loss. Before the heating season, check the seals around windows and doors, inspect gutter troughs, cable and pipe entry points. A small investment in sealing strips pays for itself within one season. At the same time – ventilation is essential for healthy air quality, but it should be short and intense (so-called shock air exchange: 5–10 minutes with the window fully open) rather than prolonged trickle ventilation through open windows.
2. Do not cover convectors with furniture or curtains
This sounds trivial, but I see it constantly in practice. A convector behind a sofa, covered by curtains, next to a shelf – these are guaranteed ways to double consumption. A convector needs free air circulation. Minimum distance from furniture and textiles is 30–50 cm, and at least 10–15 cm from the floor (which is why they are mounted low on the wall). More about installation can be read in the article "Installation of ORAVA convector on the wall – instructions and common installation mistakes".
3. Place the thermostat correctly
The room thermostat or the built-in thermostat sensor must not be near a window, door, direct sunlight, or in a draft. If the thermostat measures the wrong temperature, the boiler or convector works inefficiently – either overheating unnecessarily or underheating. The ideal placement is on an interior wall at a height of 1.2–1.5 m above the floor, in a room that represents average conditions in the apartment.
4. Use heat recovery
If you have heat recovery units or ventilation systems with a heat exchanger, keep the filters clean. A dirty filter reduces the efficiency of heat recovery and directly increases heat losses during ventilation. Filter inspection: at least once a month during the heating season.
5. Reflective panels behind radiators
With an electric boiler and radiator system, you can place a reflective foil behind each radiator on an exterior wall. This simple and cheap aid reflects heat back into the room instead of it being absorbed by the cold wall. The efficiency depends on the thickness and material of the wall, but typically it is said to save 3–8 % on that radiator.
6. Regular boiler maintenance
A neglected boiler works inefficiently. ORAVA electric boilers, unlike gas boilers, do not clog with soot, but their heating elements can scale up (if the water is hard and the circuit is not properly treated), which increases consumption. Regular inspection and maintenance are described in the article "Maintenance and service of ORAVA electric boiler – what and how often to check".
Comparison: electric boiler vs. convector in terms of consumption
Both technologies – EK boilers and VL convectors – are equally "efficient" from a physical perspective in terms of converting electrical energy into heat. Each kilowatt-hour of electrical energy is converted into exactly 1 kWh of heat (100 % efficiency). The difference is not in the efficiency itself, but in how efficiently this heat is distributed and regulated.
An electric boiler (EK-2003, EK-2004) heats water, which circulates through a radiator loop – the system has higher thermal inertia. The room temperature reacts to changes more slowly. For continuous heating of a large space, this is advantageous (more stable temperature), but for zonal control, it is less flexible.
Convector heaters (VL-201, VL-202) heat air directly in the room – they react quickly. When you turn on a convector, you feel the heat in 10–15 minutes. When you turn it off, the room cools down quickly. For rooms with alternating periods of presence and absence, convectors are more economical. For whole-house heating of a family home, a boiler system with accumulation and NT tariff is usually more advantageous in the long term.
A detailed comparison of both approaches can be found in the article "ORAVA electric boiler vs. convector – which heating type is more cost-effective".
Photovoltaics and ORAVA electric heating – a synergy that makes sense
In recent years, an increasing number of customers are combining ORAVA electric heating with a photovoltaic system on the roof. The logic is simple: electricity generated by PV panels and used directly is free (over the lifetime of the system). If you have excess electricity during the day, the boiler or convector can use it directly – without the need for a battery storage system.
Concrete example: a customer with a 6 kWp PV system heated a family home exclusively with electricity purchased from the grid. After installing the PV system and setting the boiler to run primarily during the day (when PV generates electricity), annual electricity consumption for heating dropped by 45–60 %. Naturally, PV production is lower in winter, but precisely the transitional periods (October–November, February–March) are productive and cover most of the heating needs.
Mistakes customers make that cost them money
Based on real customer orders and service visits, I have compiled a list of the most common mistakes that directly increase the cost of electric heating:
- Overdimensioned boiler without regulation: When the boiler is unnecessarily powerful and does not have properly set regulation, it operates in large on/off cycles – this increases consumption and wear.
- Thermostat set to maximum "to heat up faster": A thermostat works in ON/OFF mode – setting it to 30 °C instead of 21 °C will not heat up faster, it will just run longer and reach a higher (unnecessary) temperature.
- Manual switching on and off without a program: People turn off heating in the morning when leaving and turn it on when returning. Heating for 4–5 hours will heat the room faster than compensating for 8 hours of heat loss by throttling. In practice, throttling to 16 °C is more cost-effective than turning off and reheating to 21 °C.
- Not checking the pressure in the system: In a boiler system (EK series), a pressure drop below the minimum causes the boiler to shut off or operate inefficiently. Regular pressure checks (ideally once a month) are essential.
- Circulation pump stuck after summer: The boiler system pump can get stuck after the summer break. The first heating start in autumn should follow the procedure in the article "Common faults of ORAVA electric boilers and how to eliminate them".
Most frequently asked questions (FAQ)
How much does heating with an ORAVA electric boiler cost per month in a 50 m² apartment?
It depends on several factors, but roughly: a well-insulated 50 m² apartment in an apartment building (heated neighbors on the sides) with an ORAVA EK-2003 boiler and a properly set programmable thermostat consumes 350–550 kWh of electricity in the coldest winter months (January–February). At a price of 0.22 €/kWh, this means 77–121 € per month. With a two-tier tariff and an average price of 0.16 €/kWh (combination of HT/NT), it drops to 56–88 €. In transitional months (October, November, February, April), consumption is 150–280 kWh, which is 33–62 € per month.
Is it more cost-effective to leave an ORAVA electric heater running all day or to turn it off?
It depends on the situation. If you are at home all day, keep the heater with a thermostat on in comfort mode – it will consume only as much energy as needed to maintain the temperature. If you are away for more than 4–5 hours, switch it to a throttling mode (4–5 °C lower), not completely off. It takes a long time to reheat a room that has cooled down to 12–14 °C, and you will consume more electricity than you would save by throttling. Exception: if you are going away for the whole weekend, turning it off or using anti-frost protection (5 °C) is a reasonable choice.
Is it worth investing in an external programmable thermostat for an ORAVA electric boiler?
Definitely yes. An external room thermostat (wired or wireless) measures the room temperature more accurately than the built-in sensor in the boiler and allows for more complex programming. The return on investment (price 50–150 €) is 1–2 heating seasons with proper use. Energy savings in percentages: typically 15–25 % compared to an unprogrammed system.
What is more energy-efficient – an electric boiler with radiators or heaters in each room?
There is no one-size-fits-all answer – it depends on the type of house and usage. For a family house where all rooms are heated almost continuously, a boiler system with an NT tariff and heat accumulation is more advantageous. For an apartment or a house with significantly variable use of individual rooms (one office, one guest room), heaters with individual control are a better choice. A detailed comparison can be found in the article "Electric boiler vs. heater ORAVA – which heating type is more cost-effective".
Does connecting to a two-tier electricity tariff help with heaters as well, not just boilers?
Yes, heaters can also be connected to a circuit with HDO regulation, although it is less common and less efficient. Heaters do not have heat storage capacity – they do not heat air "in advance". Therefore, the NT tariff is most beneficial for systems with heat storage (water heater, heating water tank) or for storage cookers. For standard heaters, intelligent programming and zonal control make more sense.
Can I combine an ORAVA electric boiler with a heat pump?
Yes, such a combination is used – the electric boiler serves as a backup or auxiliary source, while the heat pump covers the basic heat demand. ORAVA EK boilers are suitable for this connection and can be linked via a common distribution panel and hydraulic distributor. This configuration significantly reduces overall heating costs, as the heat pump has a COP (coefficient of performance) of 2.5–4.5, meaning that for 1 kWh of electricity, it delivers 2.5–4.5 kWh of heat. The electric boiler only takes over when the pump is insufficient (during heavy frosts below –10 °C).
Conclusion – ORAVA electric heating is cost-effective if operated correctly
Electric heating still has a somewhat bad reputation among customers as "expensive heating". This reputation is inherited from old storage cookers without regulation and poorly insulated houses from the 1980s. Modern ORAVA electric boilers and heaters, in combination with proper regulation, zonal control, and a two-tier tariff, can be very economically competitive – without the need for a gas connection, without a boiler, without annual flue inspections, and without the risk of CO.
The key to low costs rests on three pillars: good thermal insulation of the building, properly set regulation with a weekly program, and an advantageous tariff structure. If you manage all three, ORAVA electric heating will not only be comfortable and reliable, but also financially sustainable for many years.
If you are unsure which product is right for you, read our article "How to choose an ORAVA electric boiler or heater – what to focus on" or browse the category ORAVA on atria.sk, where you will find the current offer including technical specifications.
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