Rheem Tankless Gas Code 79
Blower motor current fault. The current the blower motor is drawing is not what the board expects. Where code 61 reports the speed the fan achieved, this one reports its electrical behaviour — a motor working harder than it should, or not drawing at all.
Call a proThe verdict
Call a licensed plumber
Usually ends at the same place as code 61: the blower motor, in the combustion air path, replaced with power and gas off. A motor drawing abnormal current is often one with a seizing bearing or an obstructed wheel.
Typical cost: $250–$900
US estimate for parts and labor. Prices vary by region and by who does the work — see how we estimate costs.
What the manual says
The meaning above is transcribed from the manufacturer's diagnostic documentation for the Tankless Gas — not averaged across the brand.
Source: Rheem Tankless Gas Troubleshooting Pocket Manual (SVC820) (p. 85), read Aug 2026 — the manufacturer's own documentation for this exact series.
What you can safely check
Before anything else: if you smell gas, stop here, leave, and call your gas utility.
- Turn the unit off at the controller and at the breaker.
- Note any noise from the unit before it failed.
- Book a licensed professional.
Frequently asked questions
Would a dirty filter cause this?
It can contribute — a restricted air path changes the load on the motor. It is worth cleaning as a matter of routine, but do not expect it to clear a current fault that has already been logged.