Lochinvar 402 - 2072 Domestic water heaters, Maximum Water Flow, Model Maximum Flow

Installation & Operation Manual

8 Domestic water heaters

This section applies only to those appliances used to supply domestic hot water, installed with a storage tank(s). A circulating pump MUST be installed in the piping assembly to the storage tank and valves used to control water velocity through the appliance. Proper water velocity is important for correct operation of your water heater.

This section contains specific instructions for those appliances used to supply domestic hot water. All warnings, cautions, notes and instructions in the general installation and operation sections apply to these instructions. Water heaters are designed for installation with a storage tank. The operation of the circulating pump, proper sizing of the piping between the tank and heater and the control of water velocity, as explained in this section, are important for correct operation of your water heater.

NOTICE	To ensure proper velocity through the heat
	exchanger, it is necessary to regulate the
	temperature rise across the heat exchanger
	from inlet to outlet. This must be done
	on initial installation and periodically
	rechecked. With the correct temperature
	rise across the heat exchanger when the
	water heater is firing at 100% of rated
	input, you may be assured of the proper
	velocity in the tubes. This will yield long life
	and economical operation from your water
	heater.

Excessive lime/scale build-up in the heat exchanger tubes is a result of restricted flow and too little velocity in the tubes. Excessive pitting or erosion in the tube is caused by high water flow and too much velocity through the tubes. Care should be taken to measure temperature rise and maintain velocity as follows:

Initial set-up of maximum water flow

On initial start-up of the Copper-fin II the maximum water flow through the heat exchanger must be manually set before normal operation begins.

TABLE - 8A

MAXIMUM WATER FLOW

￿CAUTION: The maximum flow rate through a Copper-fin II water heater with a copper heat exchanger must be set to provide and not exceed the following flow:

Model	Maximum Flow
402, 502, 652, and 752	55 GPM
992, 1262, 1442, 1802, and 2072	90 GPM

If higher flow rates are required through the water heater, an optional Cupro Nickel heat exchanger is available. Consult the factory for specific application requirements.

The heat exchanger is capable of operating within the design flow rates required for the water heater, storage tank(s), and connecting piping. Erosion of the finned copper tubes may occur if the flow rate exceeds the maximum allowable flow rate through the water heater. The maximum flow rate through the water heater must be adjusted. Maximum flow on Models 402

-752 is 55 GPM and 90 GPM on Models 992 - 2072. Flow rate can be determined by measuring the temperature rise through the water heater when it is firing at full rate input.

TABLE - 8B

TEMPERATURE RISE AT FULL RATE FIRE

55 AND 90 GPM FLOW

Model	Temperature Rise °F
402	12
502	15
652	20
752	23
992	19
1262	24
1442	27
1802	34
2072	39

1.The pump must run continuously when the burner is firing.

2.With the pump running and the burner in the water heater in the off cycle, the inlet water temperature and outlet water temperature readings on the Operator Interface should read approximately the same temperatures. Water Temperature Rise on the Operator Interface should read near zero.

3.Turn the water heater on and allow time for the temperature to stabilize. The Service Mode can be used to force the water heater to run at full fire. See the Copper-fin II Service Manual for a detailed explanation of the Service Mode. Check the water temperature rise in the Operator Interface when the burner is firing at 100% of rated input.

4.Compare the water temperature rise in the Operator Interface with the required temperature rise. Should adjustment be needed, proceed as follows.

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