e4
Moderate
Rheem · HVAC Systems & Water Heaters
High Temperature Cutoff (Water Heater)
Quick Answer
Error code E4 on your Rheem HVAC Systems & Water Heaters means: High Temperature Cutoff (Water Heater). This is usually fixable — see the step-by-step guide below.
Likely Causes
How to Fix It
1
Turn off power to the water heater at the circuit breaker immediately
2
Allow the water to cool to a safe temperature before working on the unit
3
Press the high-temperature reset button on the thermostat if equipped
4
Test the heating elements for ground faults and shorts with a multimeter
5
If the thermostat or control board is causing over-temperature, it must be replaced. A licensed plumber or technician should perform the repair
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
High-temperature cutoff switch
Thermostat
Heating element
Control board
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