A beverage maker has a valve structure (13; 43; 153) adapted block the
return of water from a boiler (5) to its water reservoir (2) in response
to a water pressure from the boiler exceeding a shut-off pressure value.
The valve structure (7; 47; 107) further includes a discharge outlet (20;
120) connected for water outflow to the brewing unit (8) and is adapted
to open a passage from that inlet (9; 109) to the discharge outlet (20;
120) in response to a water pressure at the inlet (9; 109) exceeding a
discharge pressure value below the pumping pressure. The valve structure
(7; 47; 107) is further adapted to block the return of water from the
boiler (5) to the water reservoir (2) also in response to a water
pressure from the boiler below a relief pressure value above atmospheric
pressure and below the shut-off pressure value. The pressure in the
boiler during heating towards boiling is thus kept above atmospheric
pressure.