| 摘要 |
A water heater (10) has a pressure-transfer module (20) interposed between an external pressurized-water circuit and the water inside the water-heater vessel (12) so that the water is at atmospheric pressure and can thus have a free upper surface. A shut-off valve in the inlet (14) to the pressure-transfer module (20) is controlled in accordance with the water level as detected by a float (74). If the water level falls below a predetermined minimum or exceeds a predetermined maximum, the shut-off valve closes so as to prevent further flow into the water heater (10) from the upstream side of the exterior circuit. |
