How to Troubleshoot a Rheem 90 Plus

Meredith Jameson

Rheem 90 Plus gas furnaces offer an energy efficiency rating of 90 percent and come with a draft inducer, slide out blower motor, hot surface ignition and remote sensor, primary and secondary exchanger and in-shot burners to regulate the combination of air and gas.

The units are sold through select dealers or online and come with a limited warranty. Before calling for service, owners may want to try some troubleshooting efforts first to attempt to resolve the situation on their own.

  1. Plug the Rheem 90 Plus furnace into a functional power supply if it is not turning on or operating. Note that the fuse or circuit breaker may need to be replaced/reset.

  2. Turn off and unplug the Rheem unit to clean the filter if the furnace is not heating accurately. Open the main access door and disengage the retaining rod in front of the filter. Pull the filter out and vacuum carefully to remove excess dirt. Wash well with soapy water and rinse well. Air dry thoroughly before placing the filter back into the furnace.

  3. Examine the flue connection and the vent pipe if the furnace is not operating as expected. Tighten the connector and verify that the connector slopes upward.

  4. Keep the area in front of the return air grilles throughout the home clear of items that may block the air flow if the furnace is running constantly. Keep the area around the furnace clear as well and close windows and doors in the home while the furnace is operating.

  5. Contact Rheem if additional problems persist or there are any signs of damage, rust or leaking on or around the unit.


If gas is detected at any point, turn off the furnace and leave the home. Call the gas company or fire station for assistance.