Rheem Tankless Water Heater

What electrical requirements does the RTEX-18 model have?

The RTEX-18 (240 Volt) requires two 40 amp breakers and 8 AWG wire. The unit is hardwired and you will need a separate 220V line and breaker for each coil.

Does my electric tankless water heater need to be vented?

No, electric tankless units do not require venting. Only gas tankless units need to be vented.

What is the warranty coverage for the Rheem Tankless Water Heater?

The unit comes with a 5-year limited warranty on the heating chamber and a 1-year limited warranty on parts.

What does Error Code 90 mean?

Error Code 90 indicates that the air intake or vent exhaust opening may be blocked. You should inspect and clear any obstructions from the air intake and vent exhaust openings to restore normal operation.

How do I clear an error code from my Rheem Tankless Water Heater?

First, turn off all hot water faucets and press the Power ON/OFF button to turn off the water heater. Wait 5 minutes, then restart and turn on a hot water faucet to check the display. If the error persists, unplug the unit for 30 seconds, plug it back in, and repeat the process. If the error code still remains after this, contact customer service for assistance.

What is the temperature range I can set on my Rheem Tankless Water Heater?

You can set temperatures from 80°F to 140°F using the digital temperature control in 1°F increments. For temperatures above 120°F, you may need to refer to DIP switch settings in your specific product manual. Heavy-duty models can be adjusted up to 180°F.