PURPOSE: To provide a pump, which utilizes fluid force and heat of a heating medium so as to increase availability of the heating medium because the high temperature heating medium forcibly circulated to respective dwelling units is used as a power source like in a house central hot-water supply/heating system for a multiple dwelling house, etc., while provided with high safety as a primary side fluid and the secondary fluid are prevented from being mixed with each other.

CONSTITUTION: A fluid driving pump is provided with a driving impeller 21 serving as a driving source for a forcibly circulated primary side fluid and rotational force, a pump impeller 23, which is connected capable of transmitting power, to the driving impeller 21 and conveys a secondary side fluid, a partition wall 29 airtightly separating the primary side fluid from the secondary side fluid, and a heat exchanging unit 47 performing heat exchange between the primary side fluid and the secondary side fluid.