Electric Panel Heaters: A Practical Buying Guide

A cold spare bedroom, a new garden room or an under-heated rental flat rarely needs a whole-house heating redesign. It needs controlled warmth in the room that people actually use. Electric panel heaters offer a direct way to add or replace space heating, with slim wall-mounted designs, accurate thermostats and programmable controls that help avoid heating an empty room.

For many UK homes, they are particularly useful where there is no gas supply, an extension sits outside the existing central-heating layout, or a single room needs a dependable heat source without plumbing work. The right heater will feel simple to live with. The wrong one can be underpowered, expensive to run or fitted where its heat cannot circulate properly.

What electric panel heaters do well

Electric panel heaters turn electricity into heat at the point of use. In practical terms, nearly all direct electric heaters are effectively 100% efficient where they are installed: the key difference is not how much electricity becomes heat, but how well the heater controls that heat and whether the room retains it.

A panel heater mainly warms the air around it. Cooler air enters at the bottom, rises as it is heated and circulates around the room. This makes the format well suited to bedrooms, home offices, hallways, kitchens and occasional-use rooms where quick, steady background warmth is wanted.

Their slim profile is a major advantage. A wall-mounted heater takes up no floor space and avoids the pipework, boiler changes and radiator balancing associated with extending a wet central-heating system. Many models can also be used on feet where permanent mounting is not appropriate, although wall installation is normally the tidier and safer long-term option.

The trade-off is running cost. Electricity generally costs more per unit than mains gas, so electric heating works best when it is targeted. Heating one occupied room to a comfortable temperature can make more sense than running a full central-heating system for the same purpose. Using it as uncontrolled, all-day heating for a poorly insulated whole house is less likely to be economical.

Choosing the right heater output

Output is measured in watts. A heater with too little output may run continuously without bringing the room up to temperature. One that is significantly oversized can cost more to buy and may cycle more frequently, though a good thermostat will reduce this issue.

As a starting point, allow around 100 watts per square metre for an average room with standard ceiling height and reasonable insulation. A 10m² bedroom may therefore suit a heater around 1,000W. A 16m² living room might need around 1,500W to 2,000W, depending on its layout and heat loss.

This is a guide, not a guarantee. A north-facing room, single glazing, high ceilings, large patio doors, solid walls and draughts all increase the heat requirement. A modern insulated room or a well-sealed garden office may need less. For larger open-plan spaces, it can be more effective to use two suitably positioned heaters rather than relying on one large unit at the far end of the room.

Start with the room, not the heater size

Measure the floor area, then consider how the room is used. A home office needs predictable warmth through working hours. A guest room may only need frost protection and a short pre-heat period. In a rental property, clear controls and a sensible maximum temperature can help tenants use the heating comfortably without unnecessary waste.

Also consider the existing heat source. A panel heater can provide supplementary warmth in a chilly conservatory or bathroom-adjacent dressing area, while a larger installation may become the main heat source for an all-electric annexe. These are different jobs and should not be sized in the same way.

Controls make the biggest day-to-day difference

The most useful electric panel heaters are not simply on or off. Look for a precise electronic thermostat and a programmer that matches how the room is occupied. A basic timer is useful, but daily and weekly schedules give far better control where routines change between weekdays and weekends.

Wi-Fi control adds practical flexibility. You can adjust the temperature from a mobile phone, set a schedule before returning home, or check that heating has not been left running at an empty property. For landlords and holiday-let owners, this can also be useful between occupancies, provided the heater and its controls are used in line with the property’s arrangements and safety requirements.

Features such as open-window detection and adaptive start can reduce wasted energy. Open-window detection may pause heating after a sudden temperature drop, while adaptive start learns when to begin heating so the room reaches the selected temperature at the scheduled time. They are worthwhile additions, but they do not replace good insulation or sensible settings.

Avoid setting every room to the same temperature by default. Living spaces are often comfortable at around 18-21°C, while bedrooms may suit a lower setting. Lowering a target temperature even slightly can reduce energy use over time, particularly in rooms heated for long periods.

Where to position an electric panel heater

Location affects comfort as much as wattage. Position the heater where air can circulate freely and where it can counter the coldest part of the room, often beneath a window or on an external wall. Keep furniture, curtains and bedding clear of the unit and follow the manufacturer’s stated clearance distances.

Do not conceal a panel heater behind a sofa, place it in a tight alcove or use it to dry clothes. Blocking airflow reduces performance and can create a safety risk. In a home office, avoid placing the heater directly below a desk where legs, cables or storage boxes will obstruct it.

Bathrooms require particular care. Any heater installed there must be suitable for the location and fitted with the correct electrical protection. The room’s electrical zones, the product’s IP rating and the installation method all matter. If there is any doubt, ask a qualified electrician before purchasing.

Installation and electrical considerations

Some compact heaters are supplied with a plug and can be connected to an appropriate socket. Larger heaters or multiple units may need a dedicated circuit, fused spur or fixed wiring. The electrical load should always be considered, especially in extensions, converted garages and older properties where the existing circuit may already serve several appliances.

Fixed electrical work should be assessed and completed by a competent electrician in accordance with current UK requirements. This is not just about compliance. A correctly designed installation protects the circuit, provides safe isolation and gives the heater the supply it needs to operate reliably.

For landlords, electrical safety obligations and the condition of installed heating equipment need ongoing attention. Choose clearly specified, warranty-backed products and keep installation and purchase records available for future maintenance.

Running costs: what to expect

The straightforward calculation is heater output in kilowatts multiplied by hours used, then multiplied by your electricity tariff. A 1kW heater running continuously for one hour uses 1kWh of electricity. A 2kW heater uses 2kWh in the same period.

In reality, a thermostat means the heater should not draw full power continuously once the room reaches temperature. How often it cycles depends on outdoor temperature, insulation, draughts, room size and the selected setting. This is why two identical heaters can have very different running costs in different homes.

If you have a time-of-use electricity tariff, scheduling may help you use lower-cost periods where this fits your routine. However, do not heat a room unnecessarily just because a tariff window is cheaper. The best saving is still heat that stays inside a well-insulated, occupied room.

When a panel heater is the right choice

Electric panel heaters are a strong option for room-by-room heating, extensions, converted lofts, garden rooms and properties without practical access to gas. They are also useful where speed of installation, clean wall-mounted design and individual temperature control matter more than changing an entire heating system.

They may be less suitable as the only solution for a large, poorly insulated home with high, continuous heat demand. In that case, improving insulation first and considering a broader heating strategy can deliver better long-term results. The same applies where a room has persistent damp or draught problems: solve the building issue rather than asking a larger heater to compensate.

Modern Heat supplies programmable TESY electric panel heaters designed for practical domestic use, with clear product specifications, UK-held stock and UK-based support when you need help matching output and controls to a room.

Choose the heater around the space you want to heat, not the headline wattage alone. A correctly sized unit, placed well and programmed around real routines, gives you the comfort of electric heating without making energy use harder to manage.