There are several types of electric heaters available, and the cheapest one to run depends on various factors such as power output, size, and heating efficiency. Here are some of the cheapest electric heaters to run based on the search results:

• Halogen heaters: Halogen heaters are among the most cost-effective electric heater options, with a typical power output of 1200W. Their immediate warmth in close proximity saves energy by not needing to be left running for long stretches of time. The running cost of a halogen heater is around £0.20 per hour.

• Oil-filled heaters: Oil-filled heaters have been proven to be very energy efficient, quiet, and safe for households with children and pets. The cost of running this type of heater for an hour is around 22p, according to experts at Ryman.

• Infrared heaters: Infrared heaters emit a constant and gentle heat that works just like the sun. They heat objects, not air, which makes them very energy efficient. They are almost always the cheapest to run, according to Appliance Analysts.

• Convection heaters: Convection heaters are available in various sizes and power outputs, and they are often available with thermostatic control. The running cost of a fan heater is around £0.33 per hour.

• Radiator bar-style heaters: Radiator bar-style heaters tend to use around 1.2kW of power, while infrared panel heaters need as little as 300W of power. So, these heaters are often cheaper to run per hour. However, they won’t necessarily heat the room up as quickly, meaning you could need them on for longer and therefore use more electricity overall than with a fan or convection heater.

Overall, halogen heaters are the cheapest electric heaters to run due to their lower power output. However, its important to note that if electric room heaters are used for extended periods, they can become expensive to run, as electric is more expensive than gas. Therefore, its essential to choose a heater that suits your needs and has a high energy efficiency rating to minimize running expenses.