It is possible to use the boiler of a hydronic heating system to supply heat for such purposes as melting snow and ice on walks and driveways, heating a swimming pool, or heating a patio. Separate circuits are created for each of these functions and are controlled by
Their own thermostats. They are designed to tap into the main heating circuit from which they receive their supply of hot water. If winter temperatures stay at or below freezing for long periods of time, the water in an outdoor circuit must be protected with an antifreezing additive. See Chapter 5, “Heating Swimming Pools” in Volume 3 for detailed coverage of this subject.