I suppose everyone else knows but how big is the boiler and how long is a run with the old element?
Most people probably don't know the actual boiler size , it's 3" x 3 .5" tall. The original 300w heater is more than adequate , but since they aren't available anymore this replacement heater is just one more option for non-functioning #45's , the max wattage has no bearing on the matter when we're talking about minimal voltage running...any #45 should be capable of the same 😊