The home heating oil industry has a long and proud history, and Fuel Oil News has been there supporting it since 1935. It is an industry that has faced many challenges during that time. In its 77th year, Fuel Oil News is doing more than just holding
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44 AUGUST 2016 | FUEL OIL NEWS | www.fueloilnews.com be more efficient. It must be noted how- ever, that the burner and tank still must be sized to provide the amount of hot water required. Install a venturi or monoflo tee to cre- ate an even temperature exiting the tank. The use of a good quality flow restric- tor, installed in the output side of any heater, will not only ensure adequate hot water but will also aid in the control of temperatures. A good quality anti-scald, mixing or tempering valve should be installed on all water heaters to ensure that a maximum temperature exiting the tank is not exceeded. This would be an excellent deterrent to scalding in all heaters includ- ing the direct-fired heater. This would be a sound theory as long as the operating control is adjusted and operated properly. Remember nothing is perfect. Currently, the major manufacturers do not produce electrical controls to address the risks of scalding. However, history and experience have shown that these con- trols could be produced and would be if there were heating industry demands followed by a commitment to purchasing such controls. The use of temperature and relief (T&P) valves, tempering (mixing) valves, and other valves are all required under state law in the Commonwealth and elsewhere. The installation of these valves is required to protect a firm from code violations and liability suits, and to maintain warranty by the manufacturer. Bacteria growth, which occurs through nature, is not always preventable. A good installation and attention to detail are not enough. As we said previously, "lowering the water temperature in any storage tank type system may lead to the formation and growth of bacterial bodies including those linked to Legionnaire's Disease." This will not happen with a domes- tic hot water system that uses a tankless heater only. With this system, there is no tank, so all of the water is drawn and passed through the entire coil during a typical draw. So, since the tankless, Figure 6, or any complete one-pass heater is virtually immune to the problems with bacteria growth, we will make no further mention of them here. Water in storage raises concerns about bacteria growth, and since storage tank heaters are not immune from bacterial growth, we will concentrate on them. Legionnaire's disease or Legionellosis is an acute bacterial disease. The bacteria that causes the disease grows in water, and the most common sources are hot tubs, showerheads, water faucets, air condition- ing systems, tank-type hot water heaters, and water cooling towers. Most people contract the disease by inhaling mist from one of these water sources, and in some cases by aspirating contaminated water. Legionnaire's normally occurs with people who are in poor health or run down, the immune-compromised and the elderly. Cryptosporidiosis parvum is another water-borne bacterium that can cause severe, persistent life-threatening diar- rhea. It can be found in water supplies and in untreated surface water, wading and swimming pools, day-care centers, and hospitals. Originally first detected at the turn of the 20th century in animals, the first case in humans was reported in 1976. Since then there have been many reported cases all over the world and the most severe in the United States in 1993 in Milwaukee, Wis. Since cryptosporidiosis is unaffected by chlorine, is present in many animals, and is difficult to filter against, there is the possibility of it appearing in DHW storage tanks. The only way to kill the cryptosporidi- osis and Legionnaire's bacteria is through boiling of the water. If either bacterium is found in the water supply of a DHW system, the equipment should either be replaced or thoroughly steam cleaned. See ya! l F O N GEORGE LANTHIER is the owner of Firedragon Academy, a Massachusetts Certified School teaching both gas and oil. Firedragon is also a publishing firm. He is the author of over 60 books and manu- als on gas and oil heating and HVAC subjects. He is a CETP, NATE, NORA, PMAA and PMEF Proctor and has been a Massachusetts Certified Instructor since 1975. He can be reached at 608 Moose Hill Road, Leicester, MA 01524. His phone is 508-421-3490 and his website is FiredragonEnt.com. VENTURE OR MONOFLO TEE COLD HOT VACUUM RELIEF T&P VALVE DRAIN WATER HEATER BOILER BOOSTER Heat Supply TANKLESS COIL HOT Vacuum Breaker COLD Bronze Circulator Flow Check Valve T&P Valve Drain Figure 3 Figure 4 Figure 5