Heating buffer control with 9KW heaters and Auraton thermostat - anti-freeze mode

The boiler is a buffer storage tank with 3 heaters (220V) with a power output of 9KW supplied by a motor cable. The pump is coupled with an Auraton control unit which starts the pump when the water has reached the desired temperature. The system is designed to work on the night rate (hot water accumulation in the buffer tank) and to distribute it in the system on the day rate. The problem is the control of the installation in antifreeze mode. I am missing an idea for a timer to start the heaters on the night-time tariff but only when the room temperature drops to <10 deg. and for a thermostat for the pump to switch it off when the room temperature reaches 10 deg. An example cycle should look like this: The room temperature drops to 5 °C, so the thermostat switches on the heaters, but not before 10 p.m. After 8 hours of operation, the water reaches approx. 80 °C, which activates the pump circuit. The timer should switch off the heaters even though the room temperature has not changed, as it will only rise after the pump has been running for some time. The pump will circulate water until the room temperature reaches 10 °C, but no longer than until the water in the circuit cools down to a temperature that does not provide heating power. Then (if it is < 10 °C) the heaters are switched on and the whole cycle repeats, which I assume may happen once in 2-3 days.

The biggest technical problem is the thermostat on the 400 V outlet which always switches on the heaters on the night rate at < 10 degrees, but at the same time switches them off at 6.00 a.m. while the interior temperature remains unchanged. The thermostat on the pump is also a conundrum, as it is supposed to switch it on at e.g. 80 °C (here the Auraton is sufficient), but immediately switch it off when the ambient temperature reaches 10 °C. In other words, this automation should be dependent on several variables, i.e. the temperature of the interior, heating water and time.

I would be grateful for suggestions as to how to control this.

Condition for switching on the pump:
Clock=0 and Twody>T air and T air<10
or
Clock=1 and Tair<10 and Twody>80

Condition for switching on the heater:
Clock=1 and Tair<10 and Twody<Tair
or
Clock=1 and Tair<10 and Twody<80

where:
Clock=1 in 'heating' tayfy hours, otherwise zero.

This is, of course, "roughly" because the hysteresis of the system still bows.

I would do this on an arduino pro mini (cost around £10), attiny or something similar.
I would also add an internal clock support or external clock controller and two temperature sensors - total cost 50-150 PLN. Separate costs are relays/contactors/ssr's for the heaters and pump, but you can't avoid this in any solution.

Putting in comparators, thermostats etc will generate much higher costs.

Thank you very much. I will not do it myself in any case, because about integrated circuits I know only that they exist:) However, from what you write it seems that it is generally doable and at low cost. My installer fell foul of the concept itself, so I was concerned about some insurmountable technological barrier. I understand that this is definitely a job for an electronics engineer, not a plumber, based on a self-made circuit rather than off-the-shelf components from the market.
However, returning to the premise, it may be possible to ignore Twody altogether. Then both the heater and the pump are governed by clocks and T-air. In the worst case scenario, 800 litres of boiling water will cool down uselessly in the buffer storage if the air temperature rises >10 e.g. when the weather changes for the better. in other words, every drop in the air temperature >10 activates the heaters and the pump, but at different time intervals.

"Some" electronics force the comparison of water and air temps. You can, of course, look for a ready-made comparator set up with a potentiometer, but this is also electronics, only more expensive - a few hundred zloty.
It's your concept, so you decide what measurement is important. But I wouldn't give up measuring the water temp for safety reasons. You can, however, insert an additional thermostat.
Looking at the power of the heaters and the cost of the relevant contactor/ssr, the cost of the proposed control system seems negligible.
The control program is trivial, will take perhaps 15 minutes to write and can be written for you by a novice hobbyist. However, not necessarily a plumber.
Implementation on thermostats and a timer alone (without comparing water and air temps) can be done, but you need to select these thermostats appropriately in terms of hysteresis - a thermostat that is too sensitive will react to starting the circulation pump.

So it remains to find a local "hobbyist" (Masuria), unless you are involved in such realisations yourself?

I can help, it's a short topic, but that's already suggested on PW because it doesn't contribute anything on the forum. However, it would be better if someone local could help you - you will avoid postage.