I have a natural gas 4 years old State Select Water heater with Honeywell controller box (I know there is a special name for it, but it's the box on the bottom where you can change temperature and also it has a light that blinks). I also have a salt pallets water softener. I've checked the water heater, from the outside and also checked the control light and it all looks OK. The water softener is no issues as well. My problem: I've noticed in the last couple of weeks that: - with the same amount of people in the house and with the same water usage patterns - we run out of hot water rather fast. It's like it's only 35% effective comparing with the previous 100%. Do you know what the issue could be?