If you have “delay start” functions on your washing machines (dish & clothes), you can either do dishes overnight or clothes overnight as close to 3-4am as possible (assuming you’re waking up around 6 or 7).

There is not a great way to “automate” the heating of water in a traditional water heater and it would be a safety hazard to do so.

The only other good option is an inline electric water heater, but the cost of that will outweigh anything else.

If you’re eager to spend money on this, I’d look into newer appliances that you can set to run at a certain time of day if there is absolutely no functionality available.

Solenoid valve is the quick and dirty answer.

The right answer is to get your water heater serviced to figure out what’s wrong with it.

Lots of other good ideas here. I’ll just add some thoughts.

Adding some pipe insulation from the hot water heater to your shower might help a bit.

I suppose you could add some instant hot water heater system or even a second small hot water heater close to your shower to eliminate the heat up time.

If you are this interested it might be worth having a plumber come out to consult about what the issue might be and what the possibilities are. A lot might depend on your specific setup and how accessible the pipes are without completely ripping apart your walls.

It’s not that your water heater is recharging, it’s that when there is no water moving through your pipes, the hot water in the pipe eventually cools off. When you turn on the shower, all the water already in the pipes has to flow out of the shower head before the hot water in the tank heater reaches the showerhead.

You can waste a lot of water constantly running it for ten minutes, but if you’re willing to make the investment you can introduce a hot water recirculating pump into your home. A plumber adjusts your plumbing so that instead of pipes spidering out to all your taps from your hot water tank the hot water lines form a loop that returns back to the hot water heater, and the pump keeps water moving through the loop, so that any give tap always has immediate hot water (or at least warm water, the loop is never perfectly hot so you usually get a warm shower that gets hotter after a couple of minutes).

The downside is that unless your plumbing is easily accessible, the most likely approach to the loop is to use the cold water lines as the return loop, which means that instead of waiting for hot water from a cold shower, you’ll have a tap that is warm out the cold side until the loop clears and then you get cold water. They will usually leave the kitchen sink out of the loop so that people who fill their glass from the tap don’t have to wait.

Is it a gas or electric water heater?

If it’s electric you can add a tank temp sensor (to outside of tank) and a high current relay to bypass the lower thermostat and turn on the heater on command. When your sensor indicates the tank is at the desired temp you can turn off the bypass.

You might be able to do something similar on a gas water heater, but I don’t know enough about them to say.

Honestly sounds like you need a new hot water heater. It should be keeping the temp through same, whether recently used or not. If shower is far away from hot water heater, a recirculation pump may help.

You should do away with it altogether and get an inline heater. They’re magical! Hot water for hours. I’ll never go back.

If you only care about the shower in the morning, get a Thermostatic Shutoff Valve (TSV). Sounds much more complicated than it is. You let your shower run until it detects hot enough water, then slows to a trickle. You pull a small hanging cord and it opens back up, hot and ready shower. They’re like $20. We’ve had one for years and works great. It’s dumb, but it works.

My shower does this same thing. I’m a tenant and the landlord never seems to have done any preventative maintenance for their home (I’m their first tenant). It definitely is a hotter shower after someone else has already used hot water somewhere else in the house.

Not sure if this is possible or more cost effective, but can you automate or set a timer on your washing machine to do a hot rinse cycle shortly before you wake up?

Turn on the hot water for a few minutes 10 minutes b4 you shower.

I’ll answer your question first.

somehow trigger something to use hot water for like 10 minutes in order to get the hot water heater to recharge.

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.

I would bet that the thermostat in your water heater is faulty, and has a hysteresis value that is too strong.

The heater is supposed to switch on when the water temperature goes below a certain value, and switch back off when the temperature goes above a certain value. Those temperatures should be close enough, so the temperature is almost constant; but not too close, so the heater does not switch on and off constantly.

In your heater, those two values are way too far apart. When the heater is idle, it allows the water to get warm. When someone takes a shower, the temperature decreases, then it finally switches the heater on. And it does not switch the heater off until the water is hot.

Look into hot water circulating pumps.

They may be retrofit into existing home plumbing, are designed to address this exact use case, can be automated (old school timer or more intelligent with a smart switch), and will be significantly better for the environment/ your water bill. Essentially, there’s a pump located in your hot water tank closet and a small valve installed under your bathroom sink tap. They cost about $100 (though they say that’s recouped quickly because you’re not letting cold water run as long anymore), though you’ll likely need a plumber — it’s straight forward and common.

Now attached to a smart plug you could trigger it to turn on 10 minutes before your morning alarm, not run when you’re on vacation, run when your location leaves the gym (assuming you shower at home), etc.

You should check the settings on the hotwater heaters thermostat. The easiest fix is turn up the temp on the hot water heater but only do that if you have no kids in the house and warn anyone else in the house it’s been turned up.

Just wait and be the second one to take a shower. Problem solved.