How to Troubleshoot the Pressure Switch on a Laars Pool Heater

Laars pool heaters are large-scale gas-powered boiler units designed to heat commercial swimming pools. If there seem to be problems with the pressure switch, such as no gas pressure to the burners and the boiler is installed less than 3 feet below the surface of the pool, contact Laars for service and have an eyeball fitting placed on the end of the return line. If the boiler is placed more than 3 feet below the pool surface, troubleshooting may be performed to adjust the switch. Note that the pressure switch is set at 4 psi, and this pressure setting should be the final reading when making adjustments.

Air pressure gauge

Instructions

- 1
  Turn on the Laars pool heater, and allow the filter pump to run.
- 2
  Carefully increase the pressure setting until the system automatically shuts off.
- 3
  Slowly decrease the setting until the system automatically restarts.
- 4
  Attach a gas pressure gauge to the pressure switch, check the psi, and then decrease the pressure another 2 psi.
- 5
  Close the manual gas valve, and turn off the filter pump on the pool heater. Adjust the thermostat to the highest setting, and then gradually open the manual gas valve. Turn off the main power and gas valve, and contact Laars if the boiler attempts to ignite even with the filter pump turned off. Turn the filter pump back on, and restore power if the boiler does not try to fire when the filter pump is off.

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