Heating system with high heat retention transfer fluid

A heating system, comprising:

• a heat source for applying heat energy to a supply of heat transfer fluid having from 25% to 55% by volume of a polyol having five or less pendant hydroxyl groups and from 45% to 75% by volume of a polydimethylsiloxane;
• conduit to carry the heat transfer fluid to and from said heat source, said conduit including a delivery line in which the heat transfer fluid moves away from said heat source and a return line in which the heat transfer fluid is returned to said heat source;
• a heat exchanger in flow communication with said conduit to extract heat energy from said heat transfer fluid;
• a pump to move said heat transfer fluid through said conduit;
• a primary circuit including said heat source, said delivery line, said pump, said heat exchanger, and said return line;
• a sub-circuit including a bypass line interconnecting said delivery line and said return line to provide a flow path bypassing said heat source, said sub-circuit including said bypass line, a portion of said delivery line, said pump, said heat exchanger, and a portion of said return line;
• control valves in each of said delivery line, said return line and said bypass line to control the flow of heat transfer fluid between said primary circuit and said sub-circuit;
• and
• a control mechanism connected to said control valves for selectively controlling the operation of said control valves in response to a predetermined condition.