PURPOSE: To provide a cooling and heating device wherein even when a power source is turned OFF due to power failure and the action of breaker when a user side four-way valve is ON, OFF action of a pilot type user side four-way valve is ensured, whereby short-circuit takes place in said valve at the start of the following heating operation, thereby preventing stoppage of a system due to high-voltage output.

CONSTITUTION: By a user side four-way valve ON/OFF detecting means 25, ON of a user side four-way valve 9 is detected and if it is decided by a differential pressure decision means 27 that pressure difference detected by a differential pressure detecting means 26 is smaller than a set value, a flow valve 22 is driven by a flow valve drive means 28 until it is decided by the means 27 that pressure difference detected by the means 26 is larger than the set value.