Waterpik Technologies pool/spa heater 2J-5. Water Temperature Rise, Adjustment of Pressure Switch

LX and LT Pool Heaters Page 17

Pry off cap

to adjust

Figure 19. Adjustment of Pressure Switch.

To adjust the pressure switch, proceed as follows (see Figure 19).

The pool filter must be clean before making this adjustment. The heater does not have to be firing.

1.Set the heater control to the "OFF" position.

2.Start the filter pump and confirm by means of an voltmeter that the pressure switch closes (if the switch fails to close, replace it with a switch which has a lower minimum setting).

3.Set the heater control to either 'Pool' or 'Spa'. Heater should start.

4.Pry out the top rubber dirt plug on the pressure switch.

5.Use a 7/32 inch Allen wrench to turn the adjustment screw very slowly clockwise until the heater goes off.

6.Slowly turn the pressure switch adjustment screw counterclockwise one-quarter turn. The heater should come back on.

7.Check the adjustment by turning the filter pump OFF. The heater fan will continue to run but the burners should shut off immediately. If they do not, restart the filter pump and repeat Steps 6 and 7. Check the adjustment again.

8.Return the pool temperature control to the desired temperature.

It may be necessary to repeat these steps to get a proper setting. The switch must be set so that the heater will not fire unless the pump is running. If a proper setting cannot be reached, contact the factory service department.

2J-5. Water Temperature Rise

The Laars LX and LT pool heaters have an internal bypass which accommodates a wide range of water flow. The bypass is easily adjustable to change the temperature rise for optimum performance and length of heater life.

The bypass assures constant heat exchanger flow even though flow through the filter system will vary depending on how dirty the filter is.

For most installations, an external bypass valve is not needed in the heater water piping. This is due to the large size of the heater's internal bypass valve. If the pump flow rate is known to significantly exceed 125 gpm

(7.9 l/s), an external bypass may be needed to assure proper heater operation.

Water flow should be confirmed upon start-up of the heater and in most servicing situations. If the flow is not normal, corrections must be made to the pool system. Flow is evaluated by determining the water temperature rise through the heat exchanger.

Before checking the temperature rise, make sure that the pool filter is clean. If necessary, clean all components of the filter system. Temperature rise is measured in the outlet of the far-right tubes when facing the inlet/outlet water heater. To measure the temperature rise, turn off the filter pump and remove the plastic plug to the right of, and just below the level of the outlet water pipe. This is mounted flush with the heater jacket (See Figure 20). With the plug removed, install the special thread adapter and "Pete’s" plug fitting and insert a pocket thermometer.

The internal bypass can be adjusted by means of a screw on the right hand side of the header. To adjust the temperature rise to within the ranges specified in table 8, proceed as follows.

1.If the piping system has an external bypass valve, close it.

2.Set the heater's control panel to the "Off" position.

3.Start the filter pump.

4.After three minutes, note and record the thermometer reading. This is the pool water temperature.

BYPASS

ADJUSTMENT

SCREW

THERMOMETER

WITH PETE'S

PLUG

Figure 20. Temperature Rise Measurement