Lochinvar 999 - 750 Domestic Water, HEATERS Continued, Minimum Pump Performance, Heat Exchanger

Hydronic Heating Boilers and Domestic Water Heaters

DOMESTIC WATER

HEATERS Continued

This pump is sized based on installation of a single storage tank and heater in close proximity. If the number of fittings and straight pipe exceeds the quantities shown in this section, a larger pump will be required.

The standard pump selection is based on the following pipe and fittings from the unit to the storage tank:

6	- 90° elbows	2	- ball valves
2	- unions	1	- cold water tee

Not more than 45 feet of straight pipe.

IMPORTANT: For every elbow and tee in excess of those shown above, deduct 5 feet from maximum allowable straight pipe in heater to tank circulating loop.

Minimum Pump Performance

This is based on heating potable water with a hardness of 5 to 25 grains per gallon and/or total dissolved solids not exceeding 350 ppm. See Water Chemistry, page 52.

Potable Hot Water Temperature Control Settings

Domestic Water Temperatures

WARNING: You must take adequate care to prevent scald injury when storing water at elevated temperatures for domestic use.

This unit has an adjustable temperature control to maintain the desired water temperature set point. See Programming Temperature Control, page 43, for instructions to program the digital temperature control. The immersion thermostat or electronic control is factory pre-set at approximately 125°F (52°C) or less. Households with small children or invalids may require 120°F (49°C) or lower temperature hot water to reduce risk of scald injury.

Operate this high efficiency hot water heater at a temperature setting high enough to prevent condensing of the products of combustion on the unit’s heat exchanger or in the attached venting system. A water temperature setting that is above the dew point of the gas combustion products should prevent condensate formation.

TABLE-Y

Minimum Pump Performance

Btu/hr Input GPM Ft.Hd.

399,999 - 750,000 55 10

990,000 - 2,070,000 90 15

TABLE–W

Minimum

Pump

WARNING: To guard against scald injury, you must use a properly-sized thermostatic mixing valve to supply domestic hot water at temperatures less than 125°F (52°C).

Storing the water at a higher temperature and thermostatically mixing the water increases the available quantity of mixed hot water, greatly reducing the possibility of condensate forming on the heat exchanger or in the venting system and helps

Heat Exchanger

This is a highly sophisticated heat exchanger, designed to carry water in such a way that it generates a scouring action which keeps all interior surfaces free from build-up of impurities. The straight-line, two pass design of the tubes sends water into the headers at a properly rated velocity. The configuration of the headers, in turn, creates a high degree of turbulence which is sufficient to keep all contaminants in suspension. This “scouring action” provides greater cost savings for owners. Tubes are always able to transfer heat at peak efficiency. Every surface within this water containing section is of a non-ferrous material, providing clear, clean, rust-free hot water. Straight copper tubes-finned on the outside for maximum heat transfer-coated cast iron one piece cored headers make up an entirely rust-proof unit. On all models, header inspection plugs can be removed for field inspection and cleaning of copper tubes. The entire heat exchanger may be easily removed from the unit.

prevent water born bacteria growth.

Some states may require a lower water temperature setting for specific applications. Check local codes or your gas supplier for domestic hot water temperature requirements. Remember, no water heating system provides exact temperatures at all times. Let system operate a few days at your programmed settings to determine correct settings for your needs.

1.These units are equipped with an electronic operating temperature control.

2.The electronic control set points are pre-programmed to a low test setting when shipped from the factory.

3.Reprogram the temperature set points to the lowest settings which will satisfy hot water demands, eliminate a possible condensate problem and prevent a risk of scald injury.

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