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.

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.

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.

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.

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.

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

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.

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

Hot water heaters don’t work like this. Sounds like you have something wrong with the hot water heater itself.

When you first use it the water will be at the hottest point. As you continue to use the temperature will slowly go down to a certain point where the heating element can keep up with the water outgoing.

I’d get the it checked by a plumber. May need to replace heating element or the hot water heater itself.

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.

Is your water heater gas, electric, or something else?

Pretty much as everyone else has mentioned a water circulator pump would solve your first issue with taking several minutes to get hot water to your shower. The pump is usually added near your water heater and will circulate water through your hot water pipes so hot water should always be readily available at your taps.

Personally, since I had to redo the plumbing in my home anyway, I added dedicated return lines to the water heater. A friend of mine had to run his kitchen faucet for over 5 minutes to get even lukewarm water, but due to the plumbing being a long run behind finished walls we opted to install a kit with a manifold that uses the cold water line as the return. I don’t recall the brand, but it was less than $200 from Amazon and came with a pump with integral 24 hour timer and a manifold with a built-in thermostatic valve that closes so that once the water is hot it stops the flow, and opens to restart it when it cools off again. This is useful because although the cold water at that faucet isn’t as cold as without the pump, it’s not the same temperature as the hot water. With this type of setup you can also add additional manifolds at other faucets that you would like to have always hot water at. A kit like this wouldn’t be easy to add to a shower, but installing it for the bathroom sink next to the shower would have basically the same effect.

It would be best to insulate all the hot water piping that you can access, but if you can’t get to most of it (ie, it’s behind walls and in ceilings) the circulator system will be less efficient but still effective. Most of these circulator systems involve a timer, so that you’re not running the pump needlessly while you’re typically asleep or at work, but some offer manual start setups also. Keep in mind there will be a small increase in your electric and water heating utility to run the pump and maintain temperature in the pipes, though this will be partly offset by water savings if you were previously running water until it got hot before using it. With the weather and everything going on in my home I never noticed a definitive water bill reduction or gas and electric increase since installing the pump.

The issue with serving to run out of hot water faster without someone taking a shower before you doesn’t make much sense unless there’s a placebo thing going on or an issue with your water heater thermostats or heating element. Neither would be a call to replace the entire heater unit, though.

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.

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.

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