heat exchanger inlet extension 114 b a heated water duct 20 b connects to a heat exchanger outlet extension 116 b an insulating non metallic handle 142 is attached to the ends of extensions 114 b and 116 b an optional pair of brass aluminum stainless steel etc detachment couplings 138 a and 140 a provides a disconnecting point and allows for a more compact overall storage size heat exchanger 102 is shown in combination with a heat source 28 a in fig1 a in the embodiment shown heat source 28 a is a conventional liquid fueled burner of which may consume one of many liquid fuels such as propane butane petroleum naphtha etc a typical fuel burn rate of 7 500 15 000 btuh provides a suitable heating rate for the shown embodiment the general operation is much the same as with the previous embodiments however a higher heating efficiency may be obtained by placing heat exchanger 102 in a concave up position as shown in fig1 a and 15b in addition an optional heat deflector 138 fig1 b may be used to further improve heating efficiency by directing the hot exhaust gases outward maximizing the contact with heat exchanger 102 deflector 138 is approximately 125 mm 5 inches in diameter and constructed of a heat resistant material such as stainless steel a heat exchanger 102 c fig1 c in an alternate configuration is shown with heat deflector 138 and an outer enclosure 140 constructed of a heat resistant material such as aluminum steel fiberglass etc the use of enclosure 140 further improving efficiencies by channeling combustion gases around the surfaces of.