My electric towel rails were not filled when I bought my flat. I have just got around to buy some
Radiator Inhibitor and filling one of them. I filled to half way up the top rung (2.5L) and then replaced the blanking nut and bleed valve. When I turned it on it started making a fizzing whirring sound. Is that normal? I’m afraid to touch it as I don’t want to get shocked.
