Best Electric Heaters for Conservatories
A conservatory can be the brightest room in the house and the first one you stop using when temperatures fall. The best electric heaters for conservatories provide targeted warmth without extending your central-heating pipework, and give you control over when the room is heated. For most UK homes, a wall-mounted electric panel heater with a programmable thermostat is the practical starting point.
The right choice still depends on the conservatory itself. Glazing quality, floor area, ceiling height, draughts and how often the room is occupied all affect the output you need. A heater that is too small will run continuously without making the space comfortable; one that is oversized can cost more to buy and may create uneven warmth.
Choosing the best electric heaters for conservatories
Electric heating suits conservatories because it is straightforward to install and works independently from the rest of the heating system. There is no boiler, pipework or annual combustion servicing to consider. Plug-in models can be useful for occasional heat, while fixed panel heaters offer a neater, more permanent solution for a room used throughout the year.
For a typical glazed extension, heat loss is usually higher than in a well-insulated internal room. Cold glass, roof panels and air gaps can quickly pull warmth from the space, especially after dark. That means heater type matters, but sizing, controls and placement matter just as much.
Electric panel heaters: the best all-round option
An electric panel heater warms the air in the room through convection. It is slim, quiet and well suited to wall mounting beneath a window or along a solid external wall. This frees up floor space, which is particularly useful in conservatories that double as dining rooms, home offices or garden rooms.
Programmable panel heaters are the strongest choice where the room is used regularly. A thermostat helps maintain a selected temperature rather than running at full output unnecessarily, while daily and weekly schedules can bring the room up to temperature before breakfast, work or evening use. Wi-Fi control is useful if your routine changes, allowing the heater to be adjusted without walking into a cold room.
Look for an accurate electronic thermostat, open-window detection where available, and a timer that suits how you use the space. These features do not make electricity cheaper per unit, but they can reduce wasted heating time.
Infrared heaters: useful for immediate, local warmth
Infrared heaters heat people, furniture and surfaces rather than primarily heating the air. This creates a quick, direct feeling of warmth and can work well in a conservatory used for short periods, such as morning coffee or an evening meal.
They are less suited to every situation. If several people are moving around a larger room, or you want the whole conservatory to stay evenly warm for hours, a panel heater is often more comfortable. Infrared can be a sensible supplementary option, particularly near a seating area, but it should be positioned carefully so its heat reaches occupants rather than being blocked by furniture.
Oil-filled radiators and fan heaters: flexible but less permanent
Oil-filled electric radiators are portable and retain heat for a short period after switching off. They offer gentle, steady warmth and can be useful where wall mounting is not possible. Their main drawback is that they take up floor space and may be less convenient to store during summer.
Fan heaters warm a room quickly and are inexpensive to buy, but they can be noisy and are generally better for brief use than all-day heating. They are useful as a temporary solution or for taking the chill off a small conservatory, not usually as the main heater for a regularly used extension.
How much heater output does a conservatory need?
A simple starting point is to allow around 100 watts per square metre for a reasonably insulated room. Conservatories often need more because of their glazed construction, so 125 to 150 watts per square metre is a more realistic guide where insulation is limited or the room faces north.
For example, a 12 square metre conservatory may need roughly 1.5kW to 1.8kW of electric heat. A larger 18 square metre room could require 2.25kW to 2.7kW. These figures are guides, not a substitute for assessing the room. A high roof, single glazing, polycarbonate roof panels and noticeable draughts can all push the requirement upwards.
Where possible, choose two smaller heaters rather than one large unit for a wide or awkwardly shaped conservatory. Spreading the heat across separate walls can reduce cold spots and improve comfort near glazing. It also gives you more flexibility: on milder days, you may only need one heater running.
Before increasing heater size, deal with obvious heat loss. Check door seals, opening windows, roof vents and gaps around frames. Thermal blinds, lined curtains where appropriate and rugs over cold floors can make a noticeable difference. Improving the room first may allow a lower output heater to do the job more effectively.
Controls have the biggest effect on day-to-day cost
Every resistive electric heater converts electricity into heat at the point of use. The meaningful difference in running costs usually comes from how long it runs, the temperature you set and how much heat the conservatory loses.
To estimate cost, multiply the heater's kilowatt rating by the number of hours it runs, then multiply that figure by your electricity unit rate. A 1.5kW heater running for two hours uses 3kWh. The thermostat should reduce its active running time once the room reaches the chosen temperature, but a poorly insulated conservatory will need more frequent reheating.
Set a realistic temperature rather than treating the conservatory like the main living room. For reading, dining or desk work, many households find 18 to 20°C comfortable. If the room is empty for most of the day, a schedule or frost-protection setting avoids paying to heat it unnecessarily. Pre-heating for a limited period is normally more sensible than leaving a heater on continuously.
Placement and electrical safety in a conservatory
Wall-mounted heaters should have clear space around them, following the manufacturer's stated installation distances. Avoid placing furniture directly in front of a heater, covering it with textiles or fitting it where curtains can fall over the unit. Under a window is often effective because it counteracts the downdraught from cold glass, provided the required clearances can be maintained.
A permanent wall-mounted heater should be installed in line with its instructions and the electrical requirements of the property. For higher-output models or a new circuit, use a qualified electrician. Do not rely on overloaded extension leads or multi-way adaptors, especially in a room where portable heaters, lamps and charging equipment may be used together.
If the conservatory contains a hot tub, sink or other water source, heater positioning and electrical protection need additional care. Select equipment with the appropriate rating for the location and seek professional advice where there is any doubt.
What to look for before you buy
Start with the room dimensions, then consider the way it is used. A homeowner wanting quiet background heat for a garden office will usually benefit from a programmable panel heater. A landlord replacing an older portable appliance may prioritise a fixed model with simple controls, safety protection and a clear warranty. For an occasional-use dining conservatory, quick-response infrared heat or a well-controlled panel heater may be the better fit.
Check the heater's output, dimensions, mounting method and control options before ordering. A slim 1.5kW panel heater may be ideal electrically but unsuitable if there is no uninterrupted wall space. Conversely, a portable radiator may fit physically but be inconvenient if the room is already furnished.
Modern Heat supplies programmable electric panel heaters designed for practical household heating, with UK-based support available when you need help selecting a suitable output or format. Choosing a warranty-backed product from an official supplier also gives useful reassurance for a fixed heating purchase.
A conservatory does not need to become a room you close off for half the year. Match the heater to the room's heat loss, use controls that reflect your routine, and improve the obvious draughts first. The result is dependable warmth when you want it, without heating an empty glass room all day.