Lochinvar 497 - 2067 service manual Location of cold water supply piping connections

Installation & Service Manual

7 Domestic water heaters (continued)

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 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.

• Water temperature over 125°F (52°C) can cause severe burns instantly or death from scalds.

• Children, disabled and elderly are at highest risk of being scalded.

• See instruction manual before setting temperature at heating appliance.

• Feel water before bathing or showering.

• If this appliance is used to produce water that could scald if too hot, such as domestic hot water use, adjust the outlet control (limit) or use temperature limiting valves to obtain a maximum water temperature of 125°F (52°C).

Remember, no water heating system provides exact temperatures at all times. Let the system operate a few days at your desired settings to determine correct settings for your needs.

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

2.The control set points are preset to a low test setting when shipped from the factory.

3.Reset 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.

4.The High-Fire Offset should normally be adjusted to “0” when supplying potable hot water for domestic use.

5.Stage firing can be achieved by adjusting the High-Fire Offset to any value other than zero. Typically, a setting of 3°F is 5°F is suitable for stage firing in a water heater application. Stage firing of a potable water heater is normally only used to replace system standby heat loss.

6.All stages of burner operation should fire when there is a major draw from the potable hot water storage system. This prevents possible condensate problems and ensures a rapid recovery of the hot water used.

NOTICE	The High-Fire stage will be delayed by
	approximately 10 seconds to allow a
	soft start of the water heater.

WARNING	When water is stored at temperatures
	above 125°F (52°C), a thermostatic
	mixing valve must be installed on the
	hot water outlet from the storage tank
	to supply lower temperature water and
	prevent the risk of a scald injury.
	This water heater, when set at a lower
NOTICE
	temperature setting, is not capable
	of producing hot water of sufficient
	temperature for sanitizing purposes.

Location of cold water supply piping connections

Incorrect piping of the cold water supply to the system may result in excessive low temperature operation causing condensate formation on the heat exchanger and operational problems. You must install the cold water supply piping in the discharge piping from the heater to the storage tank. This allows the cold water to be tempered in the storage tank before entering the heater. See FIG. 7-1, on page 49, and typical installation drawings provided with the unit for correct piping. Higher water temperatures reduce condensate formation.

WARNING Should overheating occur or the gas supply fail to shut off, do not turn off

or disconnect the electrical supply to the pump. Instead, shut off the gas supply at a location external to the unit.

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