The 6+year-old Bunn Coffee maker CWTF-15 started taking a looong time to heat up the water inside, meaning if I pump or pour room-temperature water to make a pot, it would have to wait for more than a half hour to make the second one. That started happening a few days after I made 10 pots back-to-back without any temperature issue. I have already turned the thermostat off and then up to the highest without no effect. Would replacing water heater element help or is it just equipment's old age? Thank you.