The heater went out (0 Ohms) on my Hotspring Sovereign with 110V/1.5 kW Watkins 31255 4" flange mounted elem.ent. These elements are no longer available and I'm having no luck finding old stock. Anyone found a way to retrofit another heater? Thermcore has some flange mounted elements that are similar but I'm not sure the electronics would match up. This is a low flow setup; 1/2" fittings