<xs:element name="HeatingSystems" minOccurs="0" maxOccurs="1">
    <xs:annotation>
        <xs:documentation>
						Collection of the types of heating systems 
						used at the property.
					</xs:documentation>
        <xs:appinfo>
            <retsid>101857</retsid>
        </xs:appinfo>
    </xs:annotation>
    <xs:complexType>
        <xs:sequence>
            <xs:element name="HeatingSystem" type="commons:HeatingSystemEnum" minOccurs="1" maxOccurs="unbounded">
                <xs:annotation>
                    <xs:documentation>
									Types of heating system. Possible values are:
									Central Furnace
									Electric Air Filter
									Fireplace
									Fireplace - Insert
									Floor Furnace
									Floor Wall
									Forced Air
									Geothermal
									Gravity Air
									Gravity Hot Water
									Heat Pump
									Hot Water
									Hot Water Radiant Floor
									Humidifier
									Pellet Stove
									Radiant
									Radiant Ceiling
									Radiant Floor
									Radiator
									Solar Active
									Solar Passive
									Solar Active and Passive
									Space Heater
									Steam
									Stove
									?suspended?
									S-W Changeover
									?vent?
									Wall Unit
									Zoned
									Unknown
									Other
									None									
								</xs:documentation>
                    <xs:appinfo>
                        <retsid>101858</retsid>
                    </xs:appinfo>
                </xs:annotation>
            </xs:element>
        </xs:sequence>
    </xs:complexType>
</xs:element>