What does Rheem E5 mean?

Error code E5 on Rheem condensing tankless water heaters signals a water flow fault — the unit detects that the incoming flow rate exceeds its heating capacity, preventing it from reaching the set temperature. The control board triggers a safety lockout to avoid delivering tepid water.

What does Rheem E2 mean?

Error code E2 on the Rheem Performance Condensing ECOH series indicates a combustion fan motor fault. The control board monitors fan current during the pre-purge and ignition sequence; when the fan fails to reach rated speed or draws abnormal current, the board locks out combustion and displays E2.

What does Rheem E1 mean?

Error code E1 on the Rheem Performance Condensing ECOH series indicates an ignition failure — the control board attempted to light the burner but the flame rod did not detect a flame signal within the trial period. The board locks out after the maximum number of ignition attempts to prevent unburned gas accumulation.

How do I reset a Rheem furnace after a fault condition?

Rheem furnaces with a 2-flash or higher fault code require diagnosing and resolving the root cause before reset. For a simple thermostat or power interruption reset: turn the thermostat to OFF, turn the furnace power switch off for 30 seconds, then restore power and turn the thermostat back on. If the fault recurs immediately, the underlying condition has not been resolved.

What causes a Rheem heat pump to run continuously without reaching setpoint?

A Rheem heat pump running continuously without reaching setpoint usually indicates low refrigerant charge (check for leaks and weigh in correct charge), a defrost control fault allowing frost accumulation on the outdoor coil, or a reversing valve stuck partially in mid-position (causes mixing of hot and cold gas). Check outdoor coil temperature and compare to expected saturated suction temperature at the current outdoor ambient.

HVAC

Rheem error codes, decoded.

Look up any Rheem fault code below. Each one is grounded in Rheem's own service documentation — the meaning, the symptoms, the causes, and the steps to clear it.

By Octavian Ghindea

Co-founder & CTO · Reviewed August 2026

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Rheem sits in our HVAC coverage. Every page here is transcribed from the manufacturer's manuals, not scraped from forums.

What error codes does Rheem display?

Tap a code for the full breakdown — meaning, symptoms, causes, and fix steps.

Call for Assistance When contacting the manufacturer, the following

BKRGYBLOWBR LMTERMOTOR -98365 ULEUR 1 ERI O'AIR HER PG.F.R VALVE T/IAU BLACK, MM

B 117) 口 K AO KRGYBLOWBR UMTERMOTR OMMANDE NREMOTE ELECTRODEDE BEROEDE FLAME ROD

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