Lochinvar 2072 Heat exchanger, Initial set-up of maximum water flow, Minimum Pump Performance

4 Water connections (continued)

6 - 90° elbows 2 - ball valves

2- unions..................................................................

1 - cold water tee

Not more than 45 feet of straight pipe.

Installation & Operation Manual

Initial set-up of maximum water flow

On initial start-up of the Copper-Fin2pool heater, the maximum water flow to the heat exchanger must be checked and manually limited with a valve or bypass before normal operation begins.

NOTICE For every elbow and tee in excess of those shown above, deduct 5 feet

from the maximum allowable straight pipe in the pool heater to the system circulating loop.

Minimum Pump Performance

Pump performance is based on providing adequate flow and temperature rise to prevent scale accumulation in the heat exchanger. See Water Chemistry on page 45.

￿CAUTION

An appliance allowed to operate at return temperatures below the specified minimum setting may experience problems with the operating controls, safety switches, obstruction of the flue gas passages on the heat exchanger, incomplete combustion and possible flue gas spillage. Sustained operation at lower than specified water temperatures (140°F) may cause hazardous conditions that may result in personal injury or non-warrantable damage to the appliance.

TABLE-4B

Minimum Pump Performance and Temperature Rise

Models GPM Ft.Hd. Temperature Rise

502	55	10	15.5°F
652	55	10	20.3°F
752	55	10	23.2°F
992	90	15	18.7°F
1262	90	15	23.8°F
1442	90	15	27.2°F
1802	115	18	26.6°F
2072	115	18	30.6°F

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 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 pool heater, provided water chemistry is maintained per the Water Chemistry requirements on page 45 of this manual. A Cupro-Nickel heat exchanger is standard on 1802 - 2072 models. 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 pool heater.

￿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 pool heater.

Auxiliary Mixed Water Limit Control

Pool return and pool supply (mixed water limit) sensors (reference FIG. 4-3, page 36):

Ensure pool return and pool supply (mixed water limit) sensors are both installed in the system piping. The return sensor should be installed in the upstream of the feed water to the pool heater. The supply sensor limits the temperature of the water going back to the pool (factory adjusted to < 110°F). The supply sensor may be installed in the filtration system piping, be sure to keep it at least three (3) feet downstream from the point where the heated water from the pool heater is being added to the filtration system.

Note: In order to accurately sense water temperatures, both sensors need to be in the actual water flow.

Installation of return and supply sensors:

Both pool sensors are immersion type sensors with 1/4" NPT threads and may be installed directly into the system piping by drilling 7/16" pilot holes and tapping them with a 1/4" NPT tapered tap. Apply a small amount of high quality RTV silicone sealant to the threads to prevent leaks and install the sensors into the threaded openings in the PVC pipe. Over-tightening can damage the parts and/or strip the threads cut into the plastic pipe.

Sensor connections:

The sensors are connected to the pool heater from the factory. The return sensor is a two-wire sensor and the supply sensor is a four-wire sensor. Disconnects are provided for each sensor. If disconnected to facilitate installation, re-connection is necessary after installation. If sensors must be located further than allowed by the cables provided, any extension cabling must be of equivalent type and wire gauge (see Table 5B on page 41 of this manual for recommended gauges). IMPORTANT: If the unit is to be installed outdoors, weatherproof connections must be provided over all sensor connections.

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