Lochinvar GAS HEATER FOR COMMERICAL POOL APPLICATIONS Pool Heater Piping Installation

Installation and Service Manual

TABLE-L

Net Manifold Pressure

500,000 - 750,000

Nat. Gas	1.8" w.c.
LP Gas	4.6" w.c.
990,000 - 2,070,000
Nat. Gas	1.2" w.c.
LP Gas	4.6" w.c.

*Net Manifold Pressure equals the measured manifold pressure minus the chamber pressure. See Figure 31 to measure the Net Manifold Pressure.

pipe threads have been cut into the PVC pipe wall, the limit and bulbwell can be inserted into the tapped openings. Apply a small amount of a high quality RTV silicone sealant to the threads to prevent leaks and install the limit and bulbwell into the threaded openings in the pipe. Install the limit control and bulbwell and tighten to seal. Do not over tighten either part into the threaded openings in the PVC pipe. Over tightening can damage the parts and/or strip the threads cut into the plastic pipe. Install the pool supply sensor into the bulbwell and connect it to the pool heater circuit as shown in the wiring diagram for your model. Wire the limit into the pool heater control circuit as shown in the wiring diagram. If additional wire length is needed, use 18 GA wire for distances up to 30 ft. For longer distances, size the wire per Table M, page 37. Use weatherproof connections for outdoor installation.

POOL HEATER PIPING INSTALLATION

Install piping from the filter system to the pool heater as shown in the pool heater piping diagrams. See Figures 34 - 38. Minimum pipe diameter to and from the installed pool heater to the filter system piping on models 500,000 - 750,000 Btu/hr is 2" and on models 990,000 - 2,070,000 Btu/hr the minimum is 2-1/2". The piping from the filter system to the pool heater may be PVC, CPVC or Copper Pipe. The piping from the pool heater back to the filter system will carry water with temperatures in excess of 110°F and must be CPVC or Copper Pipe. The temperature of the heated water from the pool heater will be substantially cooled as it is mixed back into the pool water from the filter system and returned to the pool. The mix of heated water and pool water from the filtration system should only be slightly warmer than the pool water before the connections from the pool heater.

Auxiliary Mixed Water Limit Control

Ensure that the auxiliary 110°F mixed water limit control (and optional pool supply sensor, if used) are installed in the filter system piping. Install the auxiliary limit a minimum of three feet downstream from the point where the heated water from the pool heater is added to the filtration system. See Figures 34 - 38. The limit and sensor may be mounted in 3/8" NPT tapped fittings installed in the filtration system piping or they may be installed directly into tapped openings in the PVC filter system piping. Turn off the filter system pump when installing the auxiliary limit and sensor in the filtration system piping. Tapped openings can be added to the PVC pipe by first drilling 9/16" pilot holes in the PVC pipe at least three feet downstream of the point where the heated water from the pool heater is added to the filter piping. The drilled pilot holes can now be carefully threaded with a 3/8" NPT taper tap. After the

Pumped Automatic Bypass

This is a high efficiency pool heater which requires a special pumped bypass for proper operation. The bypass assembly supplied with the pool heater includes a pump and a 3-way mixing valve. All piping to connect the filter system to the pool heater is made directly to the bypass piping on the pool heater.

Outdoor Operation - Outdoor 3-Way Automatic Bypass Valve Cover

The pump supplied on the pool heater bypass has a sealed motor suitable for outdoor installations. When installing the 3-way automatic bypass valve outdoors, an outdoor valve cover is required. An outdoor valve cover is supplied with an optional outdoor vent kit (see Table H, page 26 of this manual).

To install the outdoor valve cover, follow the steps below:

1.Turn off power to the unit.

2.Remove the plastic actuator cover from the 3-way automatic bypass valve by loosening the screw above the conduit fitting (Figure 32).

3.Grasp the cover on the screw side and lift the cover up and away from the valve.

4.Disconnect the wires at the terminal block (if connected).

5.Unscrew the plastic conduit cap from the conduit fitting (Figure 32) and pull the plastic conduit hose and wires from the valve.

6.Feed the plastic conduit hose through the opening of the valve cover end cap (JKD6654) (see Figure. 32) and slide the end cap approximately one foot up the conduit.

7.Reconnect the wires to the 3-way valve circuit board as shown in Figure 33.

8.Feed the conduit hose into the conduit fitting and reinstall the conduit cap.

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