MULTIPLE HEATER FLUES

DRAIN VALVE AND ACCESS PANELS

When two or more oil-fired water heaters are connected to a single chimney or vent there shall be sufficient draft available for safe combustion and removal of combustion products to the outdoors from each heater. Refer to local codes for connection details.

Only one oil-fired water heater should be connected to any one type L venting system.

A draft regulator shall be provided for each oil-fired water heater in a multiple heater system.

DANGER

INCORRECT INSTALLATION CAN CAUSE IMPROPER OPERATION, FIRE, ASPHYXIATION, SERIOUS PERSONAL INJURY OR DEATH. NEVER OPERATE THIS WATER HEATER UNLESS IT IS PROPERLY VENTED TO THE OUTDOORSAND HAS ADEQUATE COMBUSTIONAIR SUPPLY.

WATER PIPING

GENERAL

The heaters are equipped with a 3/4" NPT drain valve mounted above and to the left of the oil burner, see FEATURES, page 2.

An access panel is located above and to the left of the oil burner and covers the flame observation port, fig. 8. A plug is inserted into the flame observation port and must be removed in order to look into the combustion chamber. Always reinstall plug before replacing access panel.

COMBUSTION CHAMBER ACCESS PORT - FIGURE 8

Select the piping diagram for the type of system to be installed from pages 15 through 19. When a circulation pump is used in the system a plug cock should be installed where indicated to regulate water flow through the heater.

RELIEF VALVE

An CSA design-certified and A.S.M.E.-rated temperature and pressure relief valve is installed in the water heater . The relief valve has a discharge capacity exceeding the maximum heater input rating and a pressure rating not exceeding the working pressure shown on the rating plate of the heater.

A temperature and pressure relief valve must also be installed on any potable water storage tank. This relief valve should have a temperature rating of 210° F (98.8°C), a pressure rating not exceeding the lowest rated working pressure of any system component, and a discharge capacity exceeding the total input of the water heaters supplying water to the storage tank.

THE PURPOSE OF A RELIEF VALVE IS TO AVOID EXCESSIVE PRESSURE OR TEMPERATURE INTO THE STEAM RANGE, WHICH MAY CAUSE SCALDING AT FIXTURES, TANK EXPLOSION, SYSTEM OR HEATER DAMAGE.

To avoid scalding or water damage, a drain line must be connected to a relief valve to direct discharge to a safe location, A DRAIN LINE MUST NOT BE REDUCED FROM THE SIZE OF THE VALVE OUTLET AND IT MUST NOT CONTAIN ANY VALVES BETWEEN THE HEATER AND THE RELIEF VALVE OR THE RELIEF VALVE AND THE DRAIN LINE EXIT. IN ADDITION, THERE SHOULD NOT BE ANY RESTRICTIONS IN A DRAIN LINE NOR SHOULD IT BE ROUTED THROUGH AREAS WHERE FREEZING CONDITIONS MIGHT OCCUR. DO NOT THREAD OR CAP THE DRAIN LINE EXIT. RESTRICTING OR BLOCKING A DRAIN LINE WILL DEFEAT THE PURPOSE OF THE RELIEF VALVE AND MAY CREATE AN UNSAFE CONDITION. Install a drain line with a downward slope such that it naturally drains itself.

Your local code authority may have other specific relief valve requirements.

NOTE: These heaters are equipped with an automatic burner shutoff system actuated by high water temperature.

CLOSED WATER SYSTEM

A closed system will exist if a back-flow preventer (check valve), pressure reducing valve, or other similar device is installed in the cold water line between the water heater and the street main (or well). Excessive pressure may develop due to the thermal expansion of heated water causing premature tank failure or intermittent relief valve operation. This type of failure is not covered by the limited warranty. An expansion tank may be necessary in the cold water supply to alleviate this situation, see installation diagrams on pages 15-19. Contact the local plumbing authority.

Another access panel is located above and to the right of the oil burner, fig. 9. This panel covers the cleanout opening in the tank which is sealed by a gasket and cover.

TANK CLEANOUT PORT - FIGURE 9

Models having ASME tank construction will have two cleanout ports. One port will be located as indicated above and the other will be located directly opposite.

Occasionally, some water seepage will occur at a cleanout port. To correct this situation, slightly tighten the cleanout cover bolts until the seepage is eliminated. Do not over tighten the bolts or the cleanout gasket will be damaged. Tighten each bolt gradually and alternate between opposed bolts on the cleanout cover.

FUEL SYSTEMS

GENERAL

The Standard for the Installation of Oil Burning Equipment-NFPA No. 31, local codes, and these instructions must be followed when installing the tank, piping and burner. In addition, an oil pump installation sheet and oil burner certificate are packed with the burner for use and completion by the installer.

On fuel systems with high pressures, a Webster "OSV" oil safety valve (Webster Electric CO., Racine, Wisc.) will be required to reduce the oil pressure at the burner pump. See FUEL PUMP, page 9, for pressure ratings of the burner's pump.

This manual and the completed oil burner certificate (CS75) are to be left with the user for future reference.

Figure 10 shows a typical single stage one or two line fuel system. When two or more tanks are connected to one burner, the supply line from each tank should run to a header fitted with an approved three-way valve. Normally only one tank may be drawn at a time unless local codes permit simultaneous feeding of two tanks on gravity type installations.

7

Page 7
Image 7
A.O. Smith COF-199 manual Water Piping, Closed Water System, Fuel Systems