The accumulator has inflow and outflow pipes (10,7) which extend inside the laminated accumulator (1) by a different amount. The heat exchanger (9) is connected to the laminated accumulator by the inflow and outflow pipes one of which contains a circulating pump (8) connected to a control (14) joined to temperature sensors (16,17) positioned at different levels in the laminated accumulator. A thermostatically controlled valve (12) is incorporated in the inflow pipes ending in the topmost part (11) of the accumulator. The valve exposes a larger flow cross-section with an increase in temperature.
