Multi-coil heat exchanger

1. A fluid heating system for meeting both a first demand and a second demand, said fluid heating system comprising:

(a) a first flow loop comprising an inlet, an outlet, a first conductor disposed between said inlet and said outlet of said first flow loop and a first pump disposed between said inlet and said outlet of said first flow loop;

(b) a second flow loop comprising an inlet, an outlet, a second conductor disposed between said inlet and said outlet of said second flow loop and a second pump disposed between said inlet and said outlet of said second flow loop;

(c) a heat source configured for transferring heat to a first flow urged by said first pump within said first flow loop at said first conductor to increase a temperature of the first flow and a second flow urged by said second pump within said second flow loop at said second conductor to increase a temperature of the second flow;

(d) a first internal bypass line comprising a first valve, said first internal bypass line connecting a first portion of said first flow loop and a second portion of said first flow loop, wherein said first internal bypass line provides a path for bypassing said inlet and said outlet of said first flow loop when the first demand does not exist and said first valve prevents a bypass of a flow from said inlet to said outlet of said first flow loop;

(e) a second internal bypass line comprising a second valve, said second internal bypass line connecting a first portion of said second flow loop and a second portion of said second flow loop and said second valve is disposed at said second portion of said second flow loop, said second valve configured to direct the second flow through said second internal bypass line, bypassing said inlet and said outlet of said second flow loop when the second demand does not exist and said second internal bypass line provides a path for the second flow when the second demand does exist; and

(f) a heat exchanger thermally coupling said first flow loop and said second flow loop, said heat exchanger is configured to cause heat transfer between the first flow of said first flow loop and the second flow of said second flow loop;

wherein said first flow loop, said second flow loop, said heat source and said heat exchanger cooperate to produce the first flow at a first temperature at said outlet of said first flow loop and the second flow at a second temperature at said outlet of said second flow loop; wherein at least one of said first and second conductor is a coil.

2. The fluid heating system of claim 1 , wherein each of said first and second conductor is a coil and said first and second conductor are configured to be interleaved to form a structure of a single-sized lumen in which said heat source is disposed.

3. The fluid heating system of claim 1 , wherein said heat source is a radial-fired burner.

4. The fluid heating system of claim 1 , further comprising a mixing line comprising a valve, said mixing line connecting a third portion of said first flow loop and a fourth portion of said first flow loop, said valve of said mixing line is configured to selectively open to allow an unheated portion of the first flow to be mixed with a heated portion of the first flow to temper the temperature of the first flow at said outlet of said first flow loop.

5. The fluid heating system of claim 1 , wherein said heat exchanger is a plate-type heat exchanger.

6. The fluid heating system of claim 1 , wherein said first valve is a check valve.

7. The fluid heating system of claim 1 , wherein said second valve is a three-way valve.

8. The fluid heating system of claim 1 , wherein the first demand is a domestic hot water demand.

9. The fluid heating system of claim 1 , wherein the second demand is a space heating demand.