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Rheem code 14 (overheat limiter): what to check

By How House Works EditorialBased on Rheem manualsChecked against sources Updated

Rheem display

14

“Water heater is overheating.”

RTGH-3, RTG-3, RTG-R-3, Ruud Mid-Efficiency · RTGH-3 Use and Care Manual, p. 75; RTG-3 Use and Care Manual, p. 77; RTG-R-3 Use and Care Manual, p. 74; RTGH-3 and RTG-3 Troubleshooting Manual, p. 41; RTG-R-3 Troubleshooting Manual, p. 34; Tankless Water Heater Use and Care Manual AP18000-2, p. 26
Technician

The RTG-R-3 chart words it "Protective overheating wrap has been broken." (RTG-R-3 manual, p. 74). Troubleshooting manual name: "Over heat limiter is active"; the manual says this is normally caused by inadequate or wrong gas supply and/or venting (AP21822 tech manual, p. 41).

What it means

Code 14 comes from the heater’s Over Heat Limiter (OHL). When the OHL has been activated or broken, the heater shows 14. Rheem’s troubleshooting manual says this is normally caused by an inadequate or wrong gas supply and/or venting RTGH-3 and RTG-3 Troubleshooting Manual, AP21822, p. 41; RTG-R-3 Troubleshooting Manual, AP24838, p. 34. All three owner charts give a single remedy: contact a dealer or qualified service technician RTGH-3 Use and Care Manual, p. 75; RTG-3 Use and Care Manual, p. 77; RTG-R-3 Use and Care Manual, p. 74.

Check these first

The charts give owners no fix for 14 itself. These steps come from other parts of the same manuals.

If a gas leak is present or suspected, do not try to find the cause yourself RTGH-3 manual, p. 5.

  1. If the heater has overheated or the gas supply does not shut off, turn off the manual gas shut-off valve to the heater. This comes from Rheem’s safety warnings RTGH-3 manual, p. 5; RTG-3 manual, p. 5; RTG-R-3 manual, p. 5; the chart row for 14 does not mention it.
  2. Reset once, as the chart section asks for any code. Close all hot water taps, turn the heater off with the POWER ON/OFF button on the remote control, wait about 5 minutes, turn it back on and open a hot tap RTGH-3 manual, p. 74; RTG-3 manual, p. 76; RTG-R-3 manual, p. 73.
  3. If 14 is still shown, turn the heater off, unplug it for about 30 seconds, plug it back in and restart. If 14 remains, turn the heater off, write down the code and call for service RTGH-3 manual, p. 74.
  4. With the heater off, check the air intake and vent outlet outside for blockage or debris. The intake needs at least 12 in. (30 cm) of clearance from any obstruction RTGH-3 manual, p. 66; RTG-3 manual, p. 68; RTG-R-3 manual, p. 65. This is a routine care check, not a remedy from the code 14 row; Rheem asks that all care around the heater be done with it turned off and its power disconnected RTGH-3 manual, p. 66.

When to call a licensed technician

  • Every case of 14. That is the only remedy the charts give.
  • The technician checks the OHL itself, and the gas supply and venting that the troubleshooting manual names as the usual causes AP21822 tech manual, p. 41. Rheem writes that manual for technicians and service professionals only AP21822 tech manual, p. 7.
  • Inlet gas pressure must stay within 4.0–10.5 in. w.c. for natural gas and 8.0–13.0 in. w.c. for propane; outside that range a gas pressure regulator must be installed RTGH-3 manual, p. 5.
  • The venting system should be inspected once a year to make sure every section is secure and airtight. The RTGH-3 manual says qualified service personnel can advise on this RTGH-3 manual, p. 64; the RTG-3 and RTG-R-3 manuals assign the inspection to a qualified service technician RTG-3 manual, p. 66; RTG-R-3 manual, p. 63.
  • Do not run the heater if the vent system shows signs of leaking exhaust RTGH-3 manual, p. 64; RTG-3 manual, p. 66; RTG-R-3 manual, p. 63.

Notes for different models

The RTG-R-3 chart describes 14 as a broken protective overheating wrap rather than an overheating heater, with the same remedy RTG-R-3 manual, p. 74.

IKONIC heaters use A014, with the same chart row as the RTGH-3 IKONIC Use and Care Manual, p. 107. Their service manual says these heaters have both an Over Heat Limiter and an Over Heat Limit Fuse, and that A014 appears if either one has been activated IKONIC Technical Training and Service Manual, p. 43.

The chart for Ruud Tankless Mid-Efficiency heaters prints the same row for 14 Tankless Water Heater Use and Care Manual AP18000-2, p. 26.

Related Rheem codes

  • 89 “High exhaust temperature detected”
  • 15 “Excessively hot water detected”
  • 90 “Air intake or vent exhaust opening may be blocked.”

All Rheem codes

Rheem is a trademark of its owner. How House Works is not affiliated with or endorsed by Rheem.

Sources

  1. Rheem Manufacturing Company. RTGH-3 Use and Care Manual. AP21820 Rev 06, no printed date; cover title: Super High Efficiency Condensing Tankless Water Heater Use and Care Manual; the same file is posted for Ruud RUTGH models; p. 1 is the unnumbered cover. Accessed Oct 12, 2026.
  2. Rheem Manufacturing Company. RTG-3 Use and Care Manual. AP22009 Rev 06, no printed date; cover title: High-Efficiency Non-Condensing Tankless Water Heater Use and Care Manual; the same file is posted for Ruud RUTG models. Accessed Oct 12, 2026.
  3. Rheem Manufacturing Company. RTG-R-3 Use and Care Manual. AP23962 Rev 02, no printed date; cover title: High-Efficiency Non-Condensing Tankless Water Heater with Recirculation Use and Care Manual; the same file is posted for Ruud RUTG-R models. Accessed Oct 12, 2026.
  4. Rheem Manufacturing Company. RTGH-3 and RTG-3 Troubleshooting Manual. AP21822 Rev 02, no issue date printed; cover title: High and Super High Efficiency Tankless Water Heater Troubleshooting Manual; written for technicians and service professionals only (p. 7). Accessed Oct 12, 2026.
  5. Rheem Manufacturing Company. RTG-R-3 Troubleshooting Manual. AP24838 Rev 01, no issue date printed; cover title: High Efficiency Tankless Water Heater with Recirculation Troubleshooting Manual; written for technicians and service professionals only (p. 6). Accessed Oct 12, 2026.
  6. Rheem Manufacturing Company. IKONIC Use and Care Manual. AP22745 Rev 07, no printed date; cover title: Condensing Tankless Water Heater Use and Care Manual; Ruud's S and SR Series pages post Rev 06. Accessed Oct 12, 2026.
  7. Rheem Manufacturing Company. IKONIC Technical Training and Service Manual. AP23209 Rev 03, no printed date; written for technicians and service professionals only (p. 4). Accessed Oct 12, 2026.
  8. Rheem Manufacturing Company (posted on ruud.com). Tankless Water Heater Use and Care Manual AP18000-2. AP18000-2 Rev 03, no printed date; cover title: Tankless Water Heater Use and Care Manual, Noncondensing 199,900 Btu/h, 180,000 Btu/h, and 150,000 Btu/h Models; the manual prints no model numbers and no -3 suffix; ruud.com posts it on its Tankless Mid-Efficiency 70, 84 and 95 product pages (2026-10-12). Accessed Oct 12, 2026.