Disadvantage of turning off oil heating

Hello

energy prices keep rising and we have now been considering whether there is a disadvantage to turning off the heating completely.
We have a single-family house from the 70s, shower briefly in the mornings and the children bathe about twice a week in the evening. We still have an oil heating system that turns on several times a day to keep the water warm that then nobody needs.

Is there a disadvantage if we introduced "bath days" and, for example, only let the water warm up every other afternoon and then everyone showers and bathes? Or is the advantage not so great if the heating is off for two days at a time?

I think in the summer you should save as much oil as possible because none of us know what the winter will be like

no, why shouldn't that work? I do the same with our gas boiler. It only runs twice briefly a day to heat the water. The rest of the day it is off. And besides, the hot water tank should also keep the water inside warm for a certain amount of time. :)

I'm a bit skeptical about that. The energy the water loses when cooling down will have to be put back in when heating it up again. It doesn't matter whether you heat it up once in a big batch or multiple times in small amounts. The only thing that helps you here is that the energy loss is higher with large temperature differences, so lukewarm water loses less energy. But the difference is hardly going to be huge with a properly insulated hot water tank.

Can you automate that properly via the control system, or do you have to go to the basement every two days, turn on the hot water, and wait 2 hours before the shower temperature is reached?

No matter if you heat up once on high or multiple times on low.

No, it’s not quite that indifferent with oil boilers. It’s like with a car. If you drive 500 meters three times a day, it’s much worse (for the car and consumption) than driving 10 km once a week. The car (the boiler) has to be brought up to temperature every time, and if long running times don’t follow, the percentage loss is much higher.

So yes. Do it that way. How big and how hot is the hot water tank? If it’s 500 liters at 60°C, it probably lasts two days. You can feel your way there. Eventually only lukewarm water comes out of the tap, then heat up once and that’s it.
And turn off the circulation pump!

I still have that in my old cabin, fortunately there is solar thermal installed there.

Maybe an idea for you: A lot of people are currently switching from gas to heat pumps, so what do they do with the often existing [ST] on the roof? If photovoltaic is installed in connection with the heat pump, it gets taken down, right...?
Wouldn't it be worth buying used [ST] and possibly a solar storage (buffer)?
My [ST] usually allows me to completely turn off the heating from late spring to early autumn ;)

Unless you want to renovate your house quickly and bring it up to low energy standard?

As already mentioned, we first need a few numbers: hot water tank size, temperature, how often does the oil burner start per day? What is the consumption during the heating period, what is it outside of it?…