I have a Creda storage heater (brick) in my livingroom, I am on TOTAL CONTROL electricity for my heating and water (Hydro Electric). I would like to remove this heater as it is big and bulky. If I did so what kind of heater could I put in its place? It is wired up to a on off socket which is connected to a total control mains box. Is there something more economical to run please. The heater is a 220v. 50/60Hz. Input 18kWh. I would appreciate any advice given Thankyou.