Ok, my first thought is do you need a whole kettle of water? Try putting in only the amount of water you actually need.
Also what type of kettle do you have?
I use a le crueset, found that pretty good.
you could also turn the temperature up a bit and see how that goes. If it makes no difference you may have a problem with the thermostat
Mine was a cook plus model , which did cooking, heating and hot water so by the time I’d boiled the kettle and made some toast it had made enough hot water for the day and warmed the bathroom.