Condensation boiler question

[SteveD]

Without making complex calculations involving many parameters, is it possible to answer the following regarding hot water supply from a gas condensation boiler?:

Which of these scenarios (A or B) is likely to be the more fuel efficient?:

A
The hot water temperature thermostat is set to a comfortable level 24/7 and only infrequently turned down during holiday absence.

B
The hot water temperature thermostat is set to a relatively low level for most of the time and is raised to a comfortable level two or three times a day as required for washing etc, then turned down again.

In other words, in scenario A, the boiler has to heat relatively warm water by a small amount but fairly frequently and in scenario B, the boiler has to heat relatively cold water by a large amount but more infrequently.

Basic information:
Boiler: Vaillant VC 306
Hot water reservoir: Vaillant VIH R 120/5 (capacity 115 litres)
Household: 3 people - 2 out at work full time, 1 at home most of the time
Showers not baths
Washing machine and dishwasher operate on the cold water supply.

[AlBags]

A. Bad.
You are maintaining a heat input all the time. If CONSTANT water temperature from the storage tank is NOT important, find timed periods in morning and evening when radiator heating is not particularly demanding of the boiler, and set up timed periods for it on the programmer .. assuming you have one.

B
No good either .. see above.

You should be able to get away with about 1 hr in early morning and 1-2 hrs evening.

[AlBags]

PS.
... (and it's a Condensing boiler)
With someone in all the time, it should be running in condensing mode most of the time, so long as rad sizes have been calculated properly.

[SteveD]

Thank you. In fact, we are already doing what you suggest for (A).