Rheem 14: Overheat Limiter Tripped

A 14 code means a Rheem tankless unit's overheat limiter — a dedicated safety switch, separate from the normal temperature dial — has tripped and shut the unit down rather than let it keep running hot.

Applies to: Rheem/Ruud tankless gas water heaters

What it means

The overheat limiter (OHL) or, on condensing models, the over-temperature vent switch has tripped. This is a hard safety cutoff, not a thermostat setting gone wrong, which is why Rheem's own guidance treats a repeat trip as a sign something upstream — gas supply, venting, or a scaled heat exchanger — needs to be fixed rather than something to keep resetting past.

Most common causes

Inadequate or wrong gas supply
Venting restriction
Sediment/scale build-up in the heat exchanger

What you can safely check yourself

There isn't much to do here beyond checking the obvious and giving it time:

Check gas supply and visible venting per the owner's manual
Allow the unit to cool — the switch may reset on its own once temperatures normalize

When to call a professional

The limiter trips more than once — this points to a heat exchanger flush or limit switch/control board replacement, not repeated resetting.

Gas supply lines, gas control valves, and venting should only be worked on by a licensed plumber or HVAC technician. Mains/line-voltage electrical work should be done with the breaker off and, beyond a simple reset, by a qualified electrician or plumber.

What the fix costs

If the limiter simply tripped once from a temporary restriction and resets clean, there's no repair cost at all. A repeat trip usually means either a heat exchanger flush ($80–$200 if hired out) or, less commonly, a limit switch or control board replacement in the $250–$600 installed range, per HomeGuide's and Angi's contractor rate data. These are rough national ranges — a licensed technician needs to see the unit to know which one applies to yours.

Related codes

All Rheem codes

Every Rheem water heater fault code — the full list on one page.

Safety. This code lookup tells you what the control board detected, not that a fix is safe to attempt. If you smell gas, see scorching, or a safety device (thermal fuse, ECO, flammable-vapor sensor) trips more than once, stop and call a licensed professional — do not keep resetting it.

Sources

Rheem/Ruud tankless troubleshooting guide, overheat limiter section (manufacturer documentation)

This site is an independent reference, not a substitute for a licensed plumber or electrician. Gas water heaters can leak carbon monoxide, leak gas, or catch fire if serviced incorrectly. Anything involving the gas line, gas control valve, venting, or main electrical wiring should be handled by a licensed professional. Pages are written with AI assistance from the sources listed on each page and checked against them before publishing.