Pressure Switch, Flame ROLL-OUT Safety Switch

PRESSURE SWITCH

The pressure switch, or heater actuator, insures that the heater operates only when the filter pump is in operation. It is located on the inlet/outlet header. It is factory set at

1.75PSI for deck level installations. When the heater is located below the level of the spa or pool, it may be necessary to reset the pressure switch to compensate for the no-flow static head. If it is necessary to reset the pressure switch, utilize the following procedure:

PRESSURE SWITCH ADJUSTMENT

FLAME ROLL-OUT SAFETY SWITCH

Atmospheric heaters are equipped with a thermal cutoff device to prevent flame roll-out in the event the heat exchanger becomes blocked. This is a "single-use" type fusible link or thermal fuse, that must be replaced when disabled by an over temperature condition, caused by excessive restriction in the heat exchanger flue passage.

Fig. #9438

Adjustment

Knob

1.With pump and heater on, turn adjustment knob clock- wise until a click is heard from the gas valve.

2.Turn adjustment knob counter clockwise 1/4 turn.

3.Turnpumpoffandonseveral times. Heater should shut off immediately. If it does not, repeat steps above until proper adjustments made.

Fig. #9440

HIGH LIMITS

The heater is equipped with two automatic high limits. Both are located in the inlet/outlet header. Both are set to open at 135°F.

NOTE: An erratic high limit is often characteristic of internal heat exchanger problem, e.g. scale buildup, defective bypass. Refer to troubleshooting sections (pg. 39).

HIGH LIMIT REMOVAL

PRESSURE SWITCH

ADJUSTMENT RANGE

Fig. # 8152.2

1.Shut off main electrical power switch to heater.

2.Remove inlet/outlet in- spection panel.

3.Remove defective high limit and replace with a new high limit.

4.Replace inspection panel.

Fig. # 9439

NOTE: If heater is installed outside of the limits shown, a higher pressure rated (11 psi) switch may be used or a flow switch mounted and wired adjacent to the heater may be used in place of the factory mounted pressure switch. See Parts List (pg. 47) for 11 psi pressure switch.

TWO-SPEED PUMPS

In some cases, the flow on the low-speed is insufficient to operate the heater. This is apparent when the pressure switch cannot be further adjusted or if the heater makes banging noises or goes off on high limit. In these cases, the pump must be run at high speed when heating the water.

CAUTION: Do not operate the heater without the function of a properly adjusted pressure switch or flow switch.

PILOT SAFETY- Millivolt

The heaters equipped with the standing pilot (millivolt system), have pilot generators which act as a safety device to shut off the flow of gas to the main burners and the pilot burner in case the pilot flame is extinguished. The pilot burner must be manually relighted to place the heater in operation again. Refer to the lighting instruc- tions provided on the heater label.

PILOT SAFETY- Electronic

The heater employs a pilot safety which closes the main gas valve within 8/10ths of a second whenever the pilot flame is interrupted. Pilot flame is automatically lit when the device is powered. Unit performs its own safety check and opens the main valve only after the pilot is proven to be lit.