I am typically the first one in my house to take a shower and I like hot showers. I have noticed that if I take a shower first, the hot water is not that hot and doesn’t last very long. But if others take showers before me and the hot water has to recharge then the hot water is HOT and lasts a long time.
I have a 50 gallon hot water tank.
The only two things I have (besides sinks and showers) that use hot water are a dumb dishwasher and a dumb washing machine.
What I was thinking was to set up an automation in HA to somehow trigger something to use hot water for like 10 minutes in order to get the hot water heater to recharge.
Any ideas?
I’ll answer your question first.
Look into hot water recirculation pumps. It will cycle the water for you, without waste.
These are typically intended for use where the shower/sink is far from the heater and there is a lengthy run of cold water before the water in the pipe is cleared. The recirculation pumps keep the water in the pipe hot, so that you don’t have to wait 60+ seconds for the shower to get hot.
Having said that; what you describe sounds like a failing heater. Either a failed heating element or a failed thermostat. There are two of each.