Here at the heat is on, we put the knowledge of what you need directly in your hands as the homeowner, so you needn’t ask or wait for information from your electrician. Here we give you complete expert guidance for this specific heating element — so you can source all parts needed to ensure a smooth and successful installation of your electric / dual fuel towel rail or radiator when your tradesman arrives.
what is a heating element?
- A heating element is used as the heat source in an electric towel rail or radiator.
- It works by heating the water or oil inside the radiator, in the same way an element heats water inside a kettle.
- We have a full guide on heating elements if you want to learn even more — click here to read the dedicated guide.
temperature control & operation
- The Terma 43D Element is pre-programmed to run at an internal temperature of 43 °C, providing Low Surface Temperature (LST) style operation.
- Designed for sensitive environments, ideal for hospitals, care homes, nurseries, and other areas where user safety is critical.
- To ensure correct surface temperature, it is advised to reduce the output of your radiator (as water) by 40% when specifying this element (e.g., for a 200 W towel rail, install a 120 W element).
- No built-in timer, but compatible with an external timer as it remembers settings when switched off.
- Includes a 2-hour drying function for towels or laundry.
- Supplied with a 565 mm internal probe length.
- 66 mm length measured from the thread down, with a 55 mm diameter clock-style face.
element specifics
- Straight cable supplied, no plug.
- IPx5 rated, suitable for use in bathroom environments.
- Class 1 electrical rating.
wattage selection advice
- Choosing the correct wattage heating element is essential for safe and effective performance.
- As listed above already - but once again as this is unique to 43D: To ensure correct surface temperature, it is advised to reduce the output of your radiator (as water) by 40% when specifying this element (e.g., for a 200 W towel rail, install a 120 W element).
- Select an element with a wattage as close as possible to the radiator’s central heating (hydronic) output measured in watts.
- If the output is listed only in BTUs, convert using the formula: BTUs ÷ 3.41 = Watts.
installation
- Full installation instructions are supplied in the accompanying manual, but the following points are useful to read in advance.
- The element must never be switched on in open air — it must be fully submerged in the heating medium to operate safely. Although fitted with safety protection, your tradesman should not power the element on to test it prior to installation.
- The supplied cable is 1.5 metres long and may be shortened or extended (daisy-chained only) as required.
- Heating elements that have been fitted cannot be accepted for change-of-mind returns.
- When installing the element, always use a spanner on the metal neck. Do not apply force to the plastic head, as this may cause cracking or damage.
electrification advice
- Before electrifying any towel rail or radiator, confirm with the manufacturer that the model is suitable for use with a heating element.
- Not all towel rails or radiators are compatible, as internal design and heat circulation vary between models.
- Installing an element into an unsuitable radiator may lead to poor performance or failure, which would not be a fault of the element.
dual fuel advice
- When using this element as part of a dual fuel installation (electric in summer, central heating in winter), the towel rail should be bled regularly.
- Air can gradually build up inside the system, which may cause overheating if the element operates without sufficient water circulation.
- A heating element must never be operated dry, as this can cause excessive surface temperatures and damage towels or clothing.
- This works on the same principle as a kettle — never run it without water inside.
guarantee & replacement
- Backed by a 2-year manufacturer’s warranty.
- The typical lifespan of a heating element is between 4 and 7 years, depending on usage.
- At end of life, the 43D heating element can be fully unscrewed and replaced as a single complete unit.
