Fast, Reliable Tankless Water Heater Repairs

Common Tankless Water Heater Problems We Diagnose and Repair

Tankless water heaters are built to last 20 years or more, but they’re complex systems with electronic controls, gas combustion components, and heat exchangers that can develop issues. When something goes wrong, you need a technician who specializes in tankless systems — not a general plumber who rarely works on them.

Our vetted local plumbing partners repair these issues every day:

No hot water or inconsistent temperatures — often caused by a failing flow sensor, clogged inlet filter, or thermistor issue. Sometimes the problem is as simple as the minimum flow rate not being met by low-flow fixtures.

Error codes on the display — every brand uses different error code systems. A Rinnai code 11 means something different from a Navien E003. Our technicians know every brand’s diagnostic codes and what they indicate.

Unit shutting down mid-use — this can signal overheating protection, venting blockage, or a failing flame rod. It requires careful diagnosis to identify the root cause.

Tankless Water Heater Error Codes by Brand: Rinnai, Navien, Noritz

Each tankless water heater manufacturer uses a unique error code system. Here’s a quick reference for the most common codes we encounter:

Rinnai — Code 11 (ignition failure), Code 12 (flame failure), Code 14 (thermal fuse). These typically indicate gas supply or venting issues.

Navien — E003 (ignition failure), E012 (flame loss), E016 (overheating). Navien units are generally reliable but sensitive to water quality.

Noritz — Code 11 (no ignition), Code 16 (overheating), Code 73 (combustion air issue). Noritz units require proper combustion air supply.

Rheem — Error codes vary by model but commonly include ignition failure, flame sensor issues, and high-temperature limit errors.

Don’t try to decode error codes yourself or repeatedly reset the unit — this can mask a developing problem. Call us for proper diagnosis.

When to Call for Tankless Repair vs. Waiting It Out

Some issues need immediate attention. Others can safely wait for a scheduled appointment.

Call immediately if you smell gas — turn off the gas supply, leave the house, and call your gas company first, then call us. Gas leaks are emergencies.

Call soon for — no hot water at all, water leaking from the unit, persistent error codes that won’t clear after one reset, or unusual odors coming from the venting system.

Can wait for a scheduled visit — intermittent temperature fluctuations, occasional lukewarm water, a single error code that clears on reset, or gradually declining hot water pressure.

Tankless Water Heater Repair Service Areas

We provide fast, expert tankless water heater repair in Tampa, Orlando, Fort Lauderdale, Jacksonville, Houston, Austin, Denver, the Inland Empire, and San Jose.

For a deeper dive into error code diagnostics, see our complete error code guide.

Get Your Tankless Repaired Right

Don’t let a minor issue become a major repair. Our vetted local plumbing partners specialize in tankless water heater diagnostics and carry parts for all major brands. Regular maintenance can prevent many common repair issues before they start. Request a repair appointment online or call 833-350-5930.