Rheem tankless water heaters show a numbered code on the controller, while Rheem tank and hybrid heaters use a status light or a display message. Below are 34 Rheem codes across 4 model series. Each one says what it means, which series it applies to, what you can safely check, and when to call a licensed pro, with a link to the Rheem document it comes from.
The same code can mean different things on different series, so match the series column to your unit. Your unit's manual is the final word. Reviewed October 2026.
34 codes
| Code | Meaning | Applies to | Safety |
|---|---|---|---|
| 1L Shown on the LED display of the remote control | Lime deposit buildup | Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display | 🧭 Check first |
| 11 Shown on the LED display of the remote control | Gas shut-off valve not fully open | Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display | 🧭 Check first |
| 12 Shown on the LED display of the remote control | Gas service interrupted or LP gas running low | Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display | 🧭 Check first |
| 14 Shown on the LED display of the remote control | Water heater overheating | Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display | 🛑 Call a pro |
| 31 Shown on the LED display of the remote control | Faulty inlet thermistor | Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display | 🛑 Call a pro |
| 33 Shown on the LED display of the remote control | Faulty outlet thermistor | Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display | 🛑 Call a pro |
| 61 Shown on the LED display of the remote control | Faulty blower motor | Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display | 🛑 Call a pro |
| 66 Shown on the LED display of the remote control | Faulty bypass motor | Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display | 🛑 Call a pro |
| P1 Shown on the LED display of the remote control | Not enough water flow | Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display | 🧭 Check first |
| 88 Shown on the LED display of the remote control | Maintenance reminder: flush heat exchanger or replace filter | Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display | ✅ Keep running |
| 90 or 99 Shown on the LED display of the remote control | Air intake or vent exhaust may be blocked | Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display | 🧭 Check first |
| 6-5 flashes Gas valve status light: six flashes, then five flashes, then a three second pause. Display models show 10. | Hard lockout (error 10) | Rheem PowerVent ESII gas tank water heaters with Honeywell electronic gas control (gas valve status light flash codes, and display codes on electronic control models) | 🛑 Call a pro |
| 6-1 flashes Gas valve status light: six flashes, then one flash, then a three second pause. Display models show 11. | Failed trial for ignition (error 11) | Rheem PowerVent ESII gas tank water heaters with Honeywell electronic gas control (gas valve status light flash codes, and display codes on electronic control models) | 🛑 Call a pro |
| 1 flash (low flame signal) Gas valve status light: one flash, then a three second pause. Display models show 12. | Low flame signal (error 12) | Rheem PowerVent ESII gas tank water heaters with Honeywell electronic gas control (gas valve status light flash codes, and display codes on electronic control models) | 🛑 Call a pro |
| 6-3 flashes Gas valve status light: six flashes, then three flashes, then a three second pause. Display models show 13. | Recycle limit, flame lost (error 13) | Rheem PowerVent ESII gas tank water heaters with Honeywell electronic gas control (gas valve status light flash codes, and display codes on electronic control models) | 🛑 Call a pro |
| 5 flashes Gas valve status light: five flashes, then a three second pause. Display models show 14. | Flame sensed out of sequence (error 14) | Rheem PowerVent ESII gas tank water heaters with Honeywell electronic gas control (gas valve status light flash codes, and display codes on electronic control models) | 🛑 Call a pro |
| 4 flashes Gas valve status light: four flashes, then a three second pause. Display models show 31. | ECO limit lockout, water too hot (error 31) | Rheem PowerVent ESII gas tank water heaters with Honeywell electronic gas control (gas valve status light flash codes, and display codes on electronic control models) | 🛑 Call a pro |
| 2 flashes Gas valve status light: two flashes, then a three second pause. Display models show 44. | Pressure switch failed closed (error 44) | Rheem PowerVent ESII gas tank water heaters with Honeywell electronic gas control (gas valve status light flash codes, and display codes on electronic control models) | 🛑 Call a pro |
| 6-2 flashes Gas valve status light: six flashes, then two flashes, then a three second pause. Display models show 45. | Recycle limit, pressure switch or limit opened (error 45) | Rheem PowerVent ESII gas tank water heaters with Honeywell electronic gas control (gas valve status light flash codes, and display codes on electronic control models) | 🛑 Call a pro |
| 3 flashes Gas valve status light: three flashes, then a three second pause. Display models show 46. | Pressure switch failed open (error 46) | Rheem PowerVent ESII gas tank water heaters with Honeywell electronic gas control (gas valve status light flash codes, and display codes on electronic control models) | 🛑 Call a pro |
| 7 flashes Gas valve status light: seven flashes, then a three second pause. Display models show 47. | Flammable vapor sensor lockout (error 47) | Rheem PowerVent ESII gas tank water heaters with Honeywell electronic gas control (gas valve status light flash codes, and display codes on electronic control models) | 🛑 Call a pro |
| A001 Alarm shown on the display | Ignition lockout | Rheem/Ruud/Richmond Residential Super High Efficiency gas tank water heaters with display and EcoNet (Use & Care Manual AP21831) | 🛑 Call a pro |
| A002 Alarm shown on the display | Flame not stable lockout | Rheem/Ruud/Richmond Residential Super High Efficiency gas tank water heaters with display and EcoNet (Use & Care Manual AP21831) | 🛑 Call a pro |
| A003 Alarm shown on the display | Intake pressure switch open | Rheem/Ruud/Richmond Residential Super High Efficiency gas tank water heaters with display and EcoNet (Use & Care Manual AP21831) | 🛑 Call a pro |
| A007 Alarm shown on the display | Exhaust pressure switch open | Rheem/Ruud/Richmond Residential Super High Efficiency gas tank water heaters with display and EcoNet (Use & Care Manual AP21831) | 🛑 Call a pro |
| A016 Alarm shown on the display | High tank temperature (ECO switch open) | Rheem/Ruud/Richmond Residential Super High Efficiency gas tank water heaters with display and EcoNet (Use & Care Manual AP21831) | 🛑 Call a pro |
| A017 Alarm shown on the display | High flue temperature | Rheem/Ruud/Richmond Residential Super High Efficiency gas tank water heaters with display and EcoNet (Use & Care Manual AP21831) | 🛑 Call a pro |
| T119 Service alert shown on the display | Time to clean the condensate drain trap | Rheem/Ruud/Richmond Residential Super High Efficiency gas tank water heaters with display and EcoNet (Use & Care Manual AP21831) | ✅ Keep running |
| A130 Alarm shown on the display | Unit off, air temperature freezing | Rheem Electric Residential Hybrid (heat pump) water heaters, Use & Care Manual AP23657 Rev 01 | 🧭 Check first |
| T131 Alert shown on the display | Clean filter reminder | Rheem Electric Residential Hybrid (heat pump) water heaters, Use & Care Manual AP23657 Rev 01 | ✅ Keep running |
| A108 Alarm shown on the display | Condensate blocked | Rheem Electric Residential Hybrid (heat pump) water heaters, Use & Care Manual AP23657 Rev 01 | 🧭 Check first |
| A008 Alarm shown on the display | Dry fire condition detected | Rheem Electric Residential Hybrid (heat pump) water heaters, Use & Care Manual AP23657 Rev 01 | 🧭 Check first |
| A107 Alarm shown on the display | Water detected on floor | Rheem Electric Residential Hybrid (heat pump) water heaters, Use & Care Manual AP23657 Rev 01 | 🧭 Check first |
| A200 Alarm shown on the display | High water temperature, ECO tripped | Rheem Electric Residential Hybrid (heat pump) water heaters, Use & Care Manual AP23657 Rev 01 | 🛑 Call a pro |
✅ Usually fine to keep running · 🧭 Check a few things first · 🛑 Turn it off and call a licensed pro
The codes Rheem documents for each series we have checked. If your series is not listed, the code may mean something different on your unit, so check its manual.
Applies to: Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display. Shows as: Shown on the LED display of the remote control
The manual says the water heater has a buildup of lime deposits.
When to call a pro: The manual says to contact a dealer or qualified service technician for lime deposits.
Applies to: Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display. Shows as: Shown on the LED display of the remote control
The manual says the water heater is overheating.
When to call a pro: Note the code, turn the heater off and call a dealer or qualified service technician, as the manual says.
Applies to: Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display. Shows as: Shown on the LED display of the remote control
The manual lists this code as a faulty inlet thermistor (a water temperature sensor).
When to call a pro: Note the code, turn the heater off and call a dealer or qualified service technician, as the manual says.
Applies to: Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display. Shows as: Shown on the LED display of the remote control
The manual lists this code as a faulty outlet thermistor (a water temperature sensor).
When to call a pro: Note the code, turn the heater off and call a dealer or qualified service technician, as the manual says.
Applies to: Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display. Shows as: Shown on the LED display of the remote control
The manual lists this code as a faulty blower motor.
When to call a pro: Note the code, turn the heater off and call a dealer or qualified service technician, as the manual says.
Applies to: Rheem non-condensing tankless gas water heaters (160,000, 180,000 and 199,900 Btu/h models) with remote control display. Shows as: Shown on the LED display of the remote control
The manual lists this code as a faulty bypass motor.
When to call a pro: Note the code, turn the heater off and call a dealer or qualified service technician, as the manual says.
Applies to: Rheem PowerVent ESII gas tank water heaters with Honeywell electronic gas control (gas valve status light flash codes, and display codes on electronic control models). Shows as: Gas valve status light: one flash, then a three second pause. Display models show 12.
One flash followed by a three second pause means a low flame signal. The control continues to operate.
When to call a pro: The bulletin lists low gas supply pressure, carbon on the electrode and pilot tube restriction. Have a qualified technician check and clean it.
Source: Rheem Technical Service Bulletin 1627, PowerVent with Honeywell Electronic Control, p. 2-3
Applies to: Rheem PowerVent ESII gas tank water heaters with Honeywell electronic gas control (gas valve status light flash codes, and display codes on electronic control models). Shows as: Gas valve status light: six flashes, then three flashes, then a three second pause. Display models show 13.
Six then three flashes. The bulletin says the pilot flame was lost during the heating cycle repeatedly and the recycle limit was reached, leading to soft and then hard lockout.
When to call a pro: The bulletin points to gas pressure, a dirty or mispositioned pilot or flame sense, a leaking pilot supply tube and baffle position. These need a qualified technician.
Source: Rheem Technical Service Bulletin 1627, PowerVent with Honeywell Electronic Control, p. 3
Applies to: Rheem PowerVent ESII gas tank water heaters with Honeywell electronic gas control (gas valve status light flash codes, and display codes on electronic control models). Shows as: Gas valve status light: five flashes, then a three second pause. Display models show 14.
Five flashes followed by a three second pause. The bulletin says flame was sensed when the pilot valve was not open, and the blower stays on.
When to call a pro: The bulletin says to replace the gas control valve if the error repeats. This is work for a qualified technician.
Source: Rheem Technical Service Bulletin 1627, PowerVent with Honeywell Electronic Control, p. 3
Applies to: Rheem PowerVent ESII gas tank water heaters with Honeywell electronic gas control (gas valve status light flash codes, and display codes on electronic control models). Shows as: Gas valve status light: two flashes, then a three second pause. Display models show 44.
Two flashes followed by a three second pause. The bulletin says the pressure switch was closed at the start of a call for heat. After repeated tries the control goes into hard lockout.
When to call a pro: The bulletin lists a blocked pressure switch tube or a faulty pressure switch. Call a qualified technician.
Source: Rheem Technical Service Bulletin 1627, PowerVent with Honeywell Electronic Control, p. 4
Applies to: Rheem PowerVent ESII gas tank water heaters with Honeywell electronic gas control (gas valve status light flash codes, and display codes on electronic control models). Shows as: Gas valve status light: six flashes, then two flashes, then a three second pause. Display models show 45.
Six then two flashes. The bulletin says the maximum number of retries has occurred and the unit is in hard lockout because the pressure switch or limit opened.
When to call a pro: The bulletin lists venting issues, wiring, a blocked switch tube, the over-temperature switch and a faulty pressure switch. Call a qualified technician.
Source: Rheem Technical Service Bulletin 1627, PowerVent with Honeywell Electronic Control, p. 5
Applies to: Rheem/Ruud/Richmond Residential Super High Efficiency gas tank water heaters with display and EcoNet (Use & Care Manual AP21831). Shows as: Alarm shown on the display
The manual says the intake pressure switch was detected open when the blower was running. This disables the heater.
When to call a pro: The manual says to check switch wiring and venting and, if it persists, contact a service provider. Call a licensed pro.
Applies to: Rheem/Ruud/Richmond Residential Super High Efficiency gas tank water heaters with display and EcoNet (Use & Care Manual AP21831). Shows as: Alarm shown on the display
The manual says the exhaust flue pressure switch was detected open during heating. This disables the heater.
When to call a pro: The manual says to check switch wiring and venting and contact a service provider if it persists. Call a licensed pro.
Applies to: Rheem/Ruud/Richmond Residential Super High Efficiency gas tank water heaters with display and EcoNet (Use & Care Manual AP21831). Shows as: Alarm shown on the display
The manual says the Energy Cutout (ECO) switch is open. This disables the heater.
When to call a pro: The manual says to refer to troubleshooting or contact a service provider. Call a licensed pro to find out why it overheated.
Applies to: Rheem/Ruud/Richmond Residential Super High Efficiency gas tank water heaters with display and EcoNet (Use & Care Manual AP21831). Shows as: Alarm shown on the display
The manual says flue (exhaust) gas temperature has exceeded 155 F. This disables the heater, and the blower keeps running until the exhaust cools.
When to call a pro: If the code returns, call a licensed pro. Flue faults are not a homeowner repair.
Applies to: Rheem/Ruud/Richmond Residential Super High Efficiency gas tank water heaters with display and EcoNet (Use & Care Manual AP21831). Shows as: Service alert shown on the display
The manual lists this as a periodic maintenance reminder: time to clean out the condensate drain trap.
When to call a pro: Call a service provider if you are not comfortable with the trap cleaning steps in the manual.
Applies to: Rheem Electric Residential Hybrid (heat pump) water heaters, Use & Care Manual AP23657 Rev 01. Shows as: Alarm shown on the display
The manual lists this as Unit Off/Air Temp Freezing: Enable Unit. The ambient temperature is below freezing.
When to call a pro: If the unit is on, the room is above freezing and the alarm stays, call a qualified service provider.
Applies to: Rheem Electric Residential Hybrid (heat pump) water heaters, Use & Care Manual AP23657 Rev 01. Shows as: Alarm shown on the display
The manual lists this as Condensate Blocked: Unclog Line. The heating source defaults to the elements because of a condensate drain blockage.
When to call a pro: The manual's steps include opening the top cover and possibly replacing the condensate sensor. Call a qualified service provider for that.
Applies to: Rheem Electric Residential Hybrid (heat pump) water heaters, Use & Care Manual AP23657 Rev 01. Shows as: Alarm shown on the display
The manual says dry fire protection has disabled the heater because there is not enough water in the storage tank.
When to call a pro: If the code stays after the tank is full and air is purged, call a qualified service provider. The manual says other board or sensor issues would show different codes.
Applies to: Rheem Electric Residential Hybrid (heat pump) water heaters, Use & Care Manual AP23657 Rev 01. Shows as: Alarm shown on the display
The manual lists this as Water Detected on Floor: Check For Leaks. Water is detected in the drain pan.
When to call a pro: The manual says that if a leak is present the unit needs service. Call a qualified service provider or plumber.
Applies to: Rheem Electric Residential Hybrid (heat pump) water heaters, Use & Care Manual AP23657 Rev 01. Shows as: Alarm shown on the display
The manual lists this as High Water Temp! [ECO] Call Tech Service. The ECO tripped and the heater is disabled.
When to call a pro: The manual's steps involve disconnecting power and testing elements and thermistors. Call a qualified service provider.
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