Hi all want to check (find) correct Heater Part Number for Indesit DIF04B1UK s/n 451930003892. Found the usual problem Heater burnt out. Thought I had a new one on Van. Looked the same but when I went to fit found the Impellor to big to go through the new Heater, Impellor Hole. When I measured Impellor’s Hole found my new one was around 55 mm and failed one is more like 58 mm Did they change size of Hole / Impellor. Just don’t want to walk in with Wrong Heater. Many Thanks