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Is your Rheem tankless water heater flashing an error code? This hub explains what the most common Rheem tankless water heater error codes mean and what to check first. For urgent repairs in Las Vegas or Henderson, call Ideal Services at (702) 396-5225.
Code 11 — No Ignition (Flame Failure)
The unit tried to light but never sensed a flame. Usually a gas-supply issue (closed valve, empty propane, low pressure), a blocked vent, or a dirty igniter. See our full guide: Rheem error code 11 — what to do.
Code 12 — Flame Loss During Operation
The burner lit but the flame went out mid-cycle. Check gas pressure and supply, verify the vent and air intake are clear, and make sure other gas appliances are working normally.
Code 13 — Combustion Abnormality
The unit detected improper combustion, often from a restricted air intake/exhaust, a dirty burner, or high altitude settings. Clear any vent blockage and have the burner inspected.
Code 14 — Overheat / Thermal Fuse
A safety sensor detected overheating. Common causes are scale buildup, a blocked vent, or restricted water flow. The unit may need descaling and a professional inspection before reuse.
Code 29 — Condensate Drain Blockage
On condensing models, the condensate line or neutralizer is clogged. Clear the drain line and replace the neutralizer media if needed.
Code 61 — Fan / Blower Motor
The combustion fan isn’t running at the expected speed. Check for debris around the fan and confirm power; a failing blower motor needs professional replacement.
Code 76 — Communication Error
The remote controller and unit aren’t communicating. Check the controller wiring and connections; loose or damaged wiring is the usual culprit.
Scale / Descaling (LC or maintenance codes)
Hard water leaves mineral scale that trips overheat and efficiency faults. Rheem tankless units should be descaled (flushed) periodically — more often on Las Vegas hard water.
Still stuck? A flashing code can mean a gas, venting, or scale problem that needs a licensed technician. Ideal Services repairs and descales Rheem tankless units across Las Vegas & Henderson. See our tankless water heater service or call (702) 396-5225.
