"If not piezo ignition, the boiler would have been ideal" - I start the heating "manually"
When we bought a boiler, we decided that it will be single-circuit, only for heating, and we will receive hot water from a gas water heater. If it breaks, then only one thing. It is cheaper than the two-circuit Italian counterpart.
One problem
The boiler itself is parapet without electronics, controlled by simple, gas, reliable automation, on the "return", only a pump.
But, there is one problem, piezo ignition lit the pilot burner once again, and now the button cannot burn it at all.
You have to remove the casing, unscrew the viewing window, and set it on fire with a homemade wick.
When the burner burns out for twenty seconds, it warms up the sensor, which controls the draft, after which you can release the button, and the flame on it will not go out.
After that I put everything in place, and turn on the main burner of the boiler,
everything starts to work normally. This has to be done once a year before starting the heating. It's annoying why manufacturers have not come up with a more reliable ignition system. They apparently decided that the system is required once a year, which means you can save on the resource of the piezoelectric element.