Liquid filled rails operate using an Electric Element to heat the liquid inside the rail. As the water particles heat up they move around the rail causing the entire rail to heat therefore warming and drying the towels.
One of the advantages of a liquid-filled rail is that you can replace the heating element if it was ever to fail. The element unscrews from the bottom of the upright and a new element can be installed. The Jeeves elements are designed to be used to replace an element if it fails. The Jeeves elements have a 5 year warranty.
Check the existing element to find the required wattage for the replacement. Jeeves elements come in 60, 120, 135, 150 & 220 watts.