Whether you can use your home boiler depends on some factors. Size of pool, boiler heat output rating, and your expectations. Probably not a good idea as typical home boilers have nowhere near the heat output of a pool heater which is sized for reasonable rates of temperature change. Where you place a NG pool heater depends on local ordinances, how the heater is designed, how it is vented, and common sense. Venting under a deck roof or near the house could lead to carbon monoxide drifting into living quarters.
Al